From d5d28607f2a093564b73df9361462e5832d44c6f Mon Sep 17 00:00:00 2001
From: Antony Polukhin <antoshkka@gmail.com>
Date: Fri, 15 Nov 2024 10:19:19 +0300
Subject: [PATCH 01/19] Easy-peasy library

---
 libraries/CMakeLists.txt                      |  4 +
 libraries/easy/CMakeLists.txt                 | 11 +++
 libraries/easy/__module_deps__.yaml           | 11 +++
 .../easy/functional_tests/CMakeLists.txt      |  6 ++
 .../functional_tests/sample/CMakeLists.txt    |  6 ++
 .../easy/functional_tests/sample/main.cpp     | 11 +++
 .../sample/static_config.yaml                 | 56 +++++++++++++
 .../functional_tests/sample/tests/conftest.py |  4 +
 .../sample/tests/test_grpc_reflection.py      | 20 +++++
 libraries/easy/include/userver/easy.hpp       | 41 +++++++++
 libraries/easy/library.yaml                   | 10 +++
 libraries/easy/src/easy.cpp                   | 84 +++++++++++++++++++
 12 files changed, 264 insertions(+)
 create mode 100644 libraries/easy/CMakeLists.txt
 create mode 100644 libraries/easy/__module_deps__.yaml
 create mode 100644 libraries/easy/functional_tests/CMakeLists.txt
 create mode 100644 libraries/easy/functional_tests/sample/CMakeLists.txt
 create mode 100644 libraries/easy/functional_tests/sample/main.cpp
 create mode 100644 libraries/easy/functional_tests/sample/static_config.yaml
 create mode 100644 libraries/easy/functional_tests/sample/tests/conftest.py
 create mode 100644 libraries/easy/functional_tests/sample/tests/test_grpc_reflection.py
 create mode 100644 libraries/easy/include/userver/easy.hpp
 create mode 100644 libraries/easy/library.yaml
 create mode 100644 libraries/easy/src/easy.cpp

diff --git a/libraries/CMakeLists.txt b/libraries/CMakeLists.txt
index 69de58e752b3..e3ac22c9fe42 100644
--- a/libraries/CMakeLists.txt
+++ b/libraries/CMakeLists.txt
@@ -5,6 +5,10 @@ if (USERVER_FEATURE_S3API)
   add_subdirectory(s3api)
 endif()
 
+if (USERVER_FEATURE_EASY)
+  add_subdirectory(easy)
+endif()
+
 if (USERVER_FEATURE_GRPC_REFLECTION)
   if (NOT USERVER_FEATURE_GRPC)
     message(FATAL_ERROR "'USERVER_FEATURE_GRPC_REFLECTION' requires 'USERVER_FEATURE_GRPC=ON'")
diff --git a/libraries/easy/CMakeLists.txt b/libraries/easy/CMakeLists.txt
new file mode 100644
index 000000000000..b5701f717159
--- /dev/null
+++ b/libraries/easy/CMakeLists.txt
@@ -0,0 +1,11 @@
+project(userver-easy CXX)
+
+userver_module(easy
+    SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}"
+    LINK_LIBRARIES userver::postgresql
+    UTEST_SOURCES "${CMAKE_CURRENT_SOURCE_DIR}/src/*_test.cpp"
+)
+
+if(USERVER_IS_THE_ROOT_PROJECT)
+  add_subdirectory(functional_tests)
+endif()
diff --git a/libraries/easy/__module_deps__.yaml b/libraries/easy/__module_deps__.yaml
new file mode 100644
index 000000000000..e04680d8449c
--- /dev/null
+++ b/libraries/easy/__module_deps__.yaml
@@ -0,0 +1,11 @@
+# THIS FILE IS AUTOGENERATED, DO NOT EDIT !!!
+version: 1
+includes:
+  - taxi/schemas/schemas/proto/grpc_reflection/__module_deps__.yaml
+paths:
+  - taxi/schemas/schemas/configs/declarations/other
+  - taxi/schemas/schemas/configs/declarations/userver
+  - taxi/schemas/schemas/configs/declarations/userver-grpc
+  - taxi/uservices/libraries/grpc-reflection
+  - taxi/uservices/userver/core
+  - taxi/uservices/userver/grpc
diff --git a/libraries/easy/functional_tests/CMakeLists.txt b/libraries/easy/functional_tests/CMakeLists.txt
new file mode 100644
index 000000000000..22b213490576
--- /dev/null
+++ b/libraries/easy/functional_tests/CMakeLists.txt
@@ -0,0 +1,6 @@
+project(userver-easy-tests CXX)
+
+add_custom_target(${PROJECT_NAME})
+
+add_subdirectory(sample)
+add_dependencies(${PROJECT_NAME} ${PROJECT_NAME}-sample)
diff --git a/libraries/easy/functional_tests/sample/CMakeLists.txt b/libraries/easy/functional_tests/sample/CMakeLists.txt
new file mode 100644
index 000000000000..9cebfa72de26
--- /dev/null
+++ b/libraries/easy/functional_tests/sample/CMakeLists.txt
@@ -0,0 +1,6 @@
+project(userver-easy-tests-sample CXX)
+
+add_executable(${PROJECT_NAME} "main.cpp")
+target_link_libraries(${PROJECT_NAME} userver::easy)
+
+userver_testsuite_add_simple()
diff --git a/libraries/easy/functional_tests/sample/main.cpp b/libraries/easy/functional_tests/sample/main.cpp
new file mode 100644
index 000000000000..1959e117f843
--- /dev/null
+++ b/libraries/easy/functional_tests/sample/main.cpp
@@ -0,0 +1,11 @@
+#include <userver/utest/using_namespace_userver.hpp>  // IWYU pragma: keep
+
+#include <userver/easy.hpp>
+
+int main(int argc, char* argv[]) {
+    return easy::Http(argc, argv) //
+      .Path("/hello", [](easy::HttpRequest& req) {
+        return "Hello world";
+      }) //
+      .Run();
+}
diff --git a/libraries/easy/functional_tests/sample/static_config.yaml b/libraries/easy/functional_tests/sample/static_config.yaml
new file mode 100644
index 000000000000..75c7635ac7fb
--- /dev/null
+++ b/libraries/easy/functional_tests/sample/static_config.yaml
@@ -0,0 +1,56 @@
+components_manager:
+    task_processors:
+        main-task-processor:
+            worker_threads: 8
+        fs-task-processor:
+            worker_threads: 4
+        grpc-blocking-task-processor:  # For blocking gRPC channel creation
+            worker_threads: 2
+            thread_name: grpc-worker
+    default_task_processor: main-task-processor
+
+    components:
+        grpc-reflection-service:
+        grpc-health:
+
+        testsuite-support:
+
+        # Common configuration for gRPC server
+        grpc-server:
+            # The single listening unix socket for incoming RPCs
+            unix-socket-path: '/tmp/my_socket'
+            completion-queue-count: 3
+            service-defaults:
+                task-processor: main-task-processor
+                middlewares: []
+
+
+
+        http-client:
+            fs-task-processor: main-task-processor
+
+        tests-control:
+            method: POST
+            path: /tests/{action}
+            skip-unregistered-testpoints: true
+            task_processor: main-task-processor
+            testpoint-timeout: 10s
+            testpoint-url: $mockserver/testpoint
+            throttling_enabled: false
+
+        logging:
+            fs-task-processor: fs-task-processor
+            loggers:
+                default:
+                    file_path: "@stderr"
+                    level: debug
+                    overflow_behavior: discard
+
+        dns-client:
+            fs-task-processor: fs-task-processor
+
+        server:
+            listener:
+                port: 8187
+                task_processor: main-task-processor
+
diff --git a/libraries/easy/functional_tests/sample/tests/conftest.py b/libraries/easy/functional_tests/sample/tests/conftest.py
new file mode 100644
index 000000000000..41ffab87fc60
--- /dev/null
+++ b/libraries/easy/functional_tests/sample/tests/conftest.py
@@ -0,0 +1,4 @@
+# /// [registration]
+# Adding a plugin from userver/testsuite/pytest_plugins/
+pytest_plugins = ['pytest_userver.plugins.core']
+# /// [registration]
diff --git a/libraries/easy/functional_tests/sample/tests/test_grpc_reflection.py b/libraries/easy/functional_tests/sample/tests/test_grpc_reflection.py
new file mode 100644
index 000000000000..4a7978bcb4d8
--- /dev/null
+++ b/libraries/easy/functional_tests/sample/tests/test_grpc_reflection.py
@@ -0,0 +1,20 @@
+# /// [Functional test]
+async def test_hello_simple(service_client):
+    response = await service_client.get('/hello')
+    assert response.status == 200
+    assert 'text/plain' in response.headers['Content-Type']
+    assert response.text == 'Hello!\n'
+    # /// [Functional test]
+    
+async def disable_test_hello_base(service_client):
+    response = await service_client.get('/hello')
+    assert response.status == 200
+    assert 'text/plain' in response.headers['Content-Type']
+    assert response.text == 'Hello, unknown user!\n'
+    assert 'X-RequestId' not in response.headers.keys(), 'Unexpected header'
+
+    response = await service_client.get('/hello', params={'name': 'userver'})
+    assert response.status == 200
+    assert 'text/plain' in response.headers['Content-Type']
+    assert response.text == 'Hello, userver!\n'
+
diff --git a/libraries/easy/include/userver/easy.hpp b/libraries/easy/include/userver/easy.hpp
new file mode 100644
index 000000000000..a0413b89f39a
--- /dev/null
+++ b/libraries/easy/include/userver/easy.hpp
@@ -0,0 +1,41 @@
+#pragma once
+
+#include <string_view>
+#include <unordered_map>
+
+#include <userver/components/component_list.hpp>
+
+USERVER_NAMESPACE_BEGIN
+
+/// @brief Top namespace for `easy` library
+namespace easy {
+
+using HttpRequest = server::http::HttpRequest;
+using RequestContext = server::request::RequestContext;
+
+class Http final {
+public:
+    using Callback = std::function<std::string(HttpRequest&);
+
+    Http(int argc, const char *const argv[]);
+    ~Http();
+
+    Http& Path(std::string_view path, Callback&& func);
+
+    int Run();
+
+private:
+    static std::unordered_map<std::string, Callback> functions_;
+
+    void AddHandleConfig(std::string_view path);
+
+    class Handle;
+
+    const int argc_;
+    const char *const argv_[];
+    components::ComponentList component_list_ = MinimalServerComponentList();
+};
+
+}  // namespace easy
+
+USERVER_NAMESPACE_END
diff --git a/libraries/easy/library.yaml b/libraries/easy/library.yaml
new file mode 100644
index 000000000000..e8a02a8eb9c3
--- /dev/null
+++ b/libraries/easy/library.yaml
@@ -0,0 +1,10 @@
+project-name: userver-grpc-reflection
+project-alt-names:
+  - yandex-userver-grpc-reflection
+description: library with reflection implementation
+
+maintainers:
+  - Common componets
+
+libraries:
+  - userver-core
diff --git a/libraries/easy/src/easy.cpp b/libraries/easy/src/easy.cpp
new file mode 100644
index 000000000000..061bc6a07e1b
--- /dev/null
+++ b/libraries/easy/src/easy.cpp
@@ -0,0 +1,84 @@
+#include <userver/easy.hpp>
+
+#include <userver/server/handlers/http_handler_base.hpp>
+
+USERVER_NAMESPACE_BEGIN
+
+namespace easy {
+
+namespace {
+
+constexpr std::string_view kConfigBase = R"~(
+components_manager:
+    task_processors:                  # Task processor is an executor for coroutine tasks
+        main-task-processor:          # Make a task processor for CPU-bound coroutine tasks.
+            worker_threads: 4         # Process tasks in 4 threads.
+
+        fs-task-processor:            # Make a separate task processor for filesystem bound tasks.
+            worker_threads: 1
+
+    default_task_processor: main-task-processor  # Task processor in which components start.
+
+    components:                       # Configuring components that were registered via component_list
+        server:
+            listener:                 # configuring the main listening socket...
+                port: 8080            # ...to listen on this port and...
+                task_processor: main-task-processor    # ...process incoming requests on this task processor.
+        logging:
+            fs-task-processor: fs-task-processor
+            loggers:
+                default:
+                    file_path: '@stderr'
+                    level: debug
+                    overflow_behavior: discard  # Drop logs if the system is too busy to write them down.
+)~";
+
+
+constexpr std::string_view kConfigHandlerTemplate = R"~(
+        {0}:
+            path: {0}                  # Registering handler by URL '{0}'.
+            method: GET,POST              # It will only reply to GET (HEAD) and POST requests.
+            task_processor: main-task-processor  # Run it on CPU bound task processor
+)~";
+
+}
+
+class Http::Handle final : public server::handlers::HttpHandlerBase, Function {
+public:
+    Handle(const components::ComponentConfig& config, const components::ComponentContext& context):
+      HttpHandlerBase(config, context),
+      callback_{Http::functions_[config.Name()]}
+    {}
+
+    std::string HandleRequestThrow(const HttpRequest& request, RequestContext&) const override {
+        return callback_(request);
+    }
+private:
+    Callback& callback_;
+};
+
+Http::Http(int argc, const char *const argv[]) : argc_{argc}, argv_{argv}, static_config_{kConfigBase} {}
+
+Http::~Http() {
+    functions_.clear();
+}
+
+Http& Http::Path(std::string_view path, Callback&& func) {
+    functions_.insert(path, std::move(func));
+    component_list_.Append<Handle>(path);
+    AddHandleConfig(path);
+
+    return *this;
+}
+
+int Http::Run() {
+    return utils::DaemonMain(argc_, argv_, component_list_);
+}
+
+void Http::AddHandleConfig(std::string_view path) {
+    static_config_ += fmt::format(kConfigHandlerTemplate, path);
+}
+
+}  // namespace easy
+
+USERVER_NAMESPACE_END

From 93e5379f2bdb3203da1ccc355556f1f89b1665c1 Mon Sep 17 00:00:00 2001
From: Antony Polukhin <antoshkka@gmail.com>
Date: Fri, 15 Nov 2024 13:12:41 +0300
Subject: [PATCH 02/19] Its alive

---
 cmake/UserverTestsuite.cmake                  |  9 +++
 cmake/install/userver-easy-config.cmake       | 13 +++++
 libraries/CMakeLists.txt                      |  3 +
 libraries/easy/CMakeLists.txt                 |  2 +-
 libraries/easy/__module_deps__.yaml           | 11 ----
 .../easy/functional_tests/CMakeLists.txt      |  6 --
 .../easy/functional_tests/sample/main.cpp     | 11 ----
 .../sample/static_config.yaml                 | 56 -------------------
 .../sample/tests/test_grpc_reflection.py      | 20 -------
 libraries/easy/include/userver/easy.hpp       | 15 +++--
 libraries/easy/library.yaml                   | 10 ----
 .../0_hello_world}/CMakeLists.txt             |  4 +-
 libraries/easy/samples/0_hello_world/main.cpp | 13 +++++
 .../0_hello_world}/tests/conftest.py          |  0
 .../samples/0_hello_world/tests/test_basic.py |  7 +++
 libraries/easy/samples/CMakeLists.txt         |  6 ++
 libraries/easy/src/easy.cpp                   | 50 ++++++++++++++---
 .../pytest_userver/plugins/config.py          | 10 +++-
 18 files changed, 115 insertions(+), 131 deletions(-)
 create mode 100644 cmake/install/userver-easy-config.cmake
 delete mode 100644 libraries/easy/__module_deps__.yaml
 delete mode 100644 libraries/easy/functional_tests/CMakeLists.txt
 delete mode 100644 libraries/easy/functional_tests/sample/main.cpp
 delete mode 100644 libraries/easy/functional_tests/sample/static_config.yaml
 delete mode 100644 libraries/easy/functional_tests/sample/tests/test_grpc_reflection.py
 delete mode 100644 libraries/easy/library.yaml
 rename libraries/easy/{functional_tests/sample => samples/0_hello_world}/CMakeLists.txt (51%)
 create mode 100644 libraries/easy/samples/0_hello_world/main.cpp
 rename libraries/easy/{functional_tests/sample => samples/0_hello_world}/tests/conftest.py (100%)
 create mode 100644 libraries/easy/samples/0_hello_world/tests/test_basic.py
 create mode 100644 libraries/easy/samples/CMakeLists.txt

diff --git a/cmake/UserverTestsuite.cmake b/cmake/UserverTestsuite.cmake
index 80a3198ce5ee..d6946fb81c55 100644
--- a/cmake/UserverTestsuite.cmake
+++ b/cmake/UserverTestsuite.cmake
@@ -308,6 +308,7 @@ function(userver_testsuite_add_simple)
       CONFIG_VARS_PATH
       DYNAMIC_CONFIG_FALLBACK_PATH
       SECDIST_PATH
+      DUMP_CONFIG
   )
   set(multiValueArgs
       PYTEST_ARGS
@@ -358,9 +359,16 @@ function(userver_testsuite_add_simple)
     set(ARG_TEST_SUFFIX "")
   endif()
 
+  set(DUMP_CONFIG_OPTION "")
+  if (ARG_DUMP_CONFIG)
+    set(DUMP_CONFIG_OPTION "--dump-config")
+  endif()
+
   if(ARG_CONFIG_PATH)
     get_filename_component(config_path "${ARG_CONFIG_PATH}"
         REALPATH BASE_DIR "${CMAKE_CURRENT_SOURCE_DIR}")
+  elseif(ARG_DUMP_CONFIG)
+    set(config_path "${CMAKE_CURRENT_BINARY_DIR}/Testing/Temporary/static_config.yaml")
   else()
     foreach(probable_config_path IN ITEMS
         "${CMAKE_CURRENT_SOURCE_DIR}/configs/static_config.yaml"
@@ -460,6 +468,7 @@ function(userver_testsuite_add_simple)
       "--service-config=${config_path}"
       "--service-source-dir=${CMAKE_CURRENT_SOURCE_DIR}"
       "--service-binary=${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}"
+      "${DUMP_CONFIG_OPTION}"
       ${pytest_additional_args}
       ${ARG_PYTEST_ARGS}
       REQUIREMENTS ${ARG_REQUIREMENTS}
diff --git a/cmake/install/userver-easy-config.cmake b/cmake/install/userver-easy-config.cmake
new file mode 100644
index 000000000000..40caf93a1c06
--- /dev/null
+++ b/cmake/install/userver-easy-config.cmake
@@ -0,0 +1,13 @@
+include_guard(GLOBAL)
+
+if(userver_easy_FOUND)
+  return()
+endif()
+
+find_package(userver REQUIRED COMPONENTS
+    core
+    postgresql
+)
+
+set(userver_easy_FOUND TRUE)
+
diff --git a/libraries/CMakeLists.txt b/libraries/CMakeLists.txt
index e3ac22c9fe42..4c504f678e4d 100644
--- a/libraries/CMakeLists.txt
+++ b/libraries/CMakeLists.txt
@@ -6,6 +6,9 @@ if (USERVER_FEATURE_S3API)
 endif()
 
 if (USERVER_FEATURE_EASY)
+  if (NOT USERVER_FEATURE_POSTGRESQL)
+    message(FATAL_ERROR "'USERVER_FEATURE_EASY' requires 'USERVER_FEATURE_POSTGRESQL=ON'")
+  endif()
   add_subdirectory(easy)
 endif()
 
diff --git a/libraries/easy/CMakeLists.txt b/libraries/easy/CMakeLists.txt
index b5701f717159..67e1813b1990 100644
--- a/libraries/easy/CMakeLists.txt
+++ b/libraries/easy/CMakeLists.txt
@@ -7,5 +7,5 @@ userver_module(easy
 )
 
 if(USERVER_IS_THE_ROOT_PROJECT)
-  add_subdirectory(functional_tests)
+  add_subdirectory(samples)
 endif()
diff --git a/libraries/easy/__module_deps__.yaml b/libraries/easy/__module_deps__.yaml
deleted file mode 100644
index e04680d8449c..000000000000
--- a/libraries/easy/__module_deps__.yaml
+++ /dev/null
@@ -1,11 +0,0 @@
-# THIS FILE IS AUTOGENERATED, DO NOT EDIT !!!
-version: 1
-includes:
-  - taxi/schemas/schemas/proto/grpc_reflection/__module_deps__.yaml
-paths:
-  - taxi/schemas/schemas/configs/declarations/other
-  - taxi/schemas/schemas/configs/declarations/userver
-  - taxi/schemas/schemas/configs/declarations/userver-grpc
-  - taxi/uservices/libraries/grpc-reflection
-  - taxi/uservices/userver/core
-  - taxi/uservices/userver/grpc
diff --git a/libraries/easy/functional_tests/CMakeLists.txt b/libraries/easy/functional_tests/CMakeLists.txt
deleted file mode 100644
index 22b213490576..000000000000
--- a/libraries/easy/functional_tests/CMakeLists.txt
+++ /dev/null
@@ -1,6 +0,0 @@
-project(userver-easy-tests CXX)
-
-add_custom_target(${PROJECT_NAME})
-
-add_subdirectory(sample)
-add_dependencies(${PROJECT_NAME} ${PROJECT_NAME}-sample)
diff --git a/libraries/easy/functional_tests/sample/main.cpp b/libraries/easy/functional_tests/sample/main.cpp
deleted file mode 100644
index 1959e117f843..000000000000
--- a/libraries/easy/functional_tests/sample/main.cpp
+++ /dev/null
@@ -1,11 +0,0 @@
-#include <userver/utest/using_namespace_userver.hpp>  // IWYU pragma: keep
-
-#include <userver/easy.hpp>
-
-int main(int argc, char* argv[]) {
-    return easy::Http(argc, argv) //
-      .Path("/hello", [](easy::HttpRequest& req) {
-        return "Hello world";
-      }) //
-      .Run();
-}
diff --git a/libraries/easy/functional_tests/sample/static_config.yaml b/libraries/easy/functional_tests/sample/static_config.yaml
deleted file mode 100644
index 75c7635ac7fb..000000000000
--- a/libraries/easy/functional_tests/sample/static_config.yaml
+++ /dev/null
@@ -1,56 +0,0 @@
-components_manager:
-    task_processors:
-        main-task-processor:
-            worker_threads: 8
-        fs-task-processor:
-            worker_threads: 4
-        grpc-blocking-task-processor:  # For blocking gRPC channel creation
-            worker_threads: 2
-            thread_name: grpc-worker
-    default_task_processor: main-task-processor
-
-    components:
-        grpc-reflection-service:
-        grpc-health:
-
-        testsuite-support:
-
-        # Common configuration for gRPC server
-        grpc-server:
-            # The single listening unix socket for incoming RPCs
-            unix-socket-path: '/tmp/my_socket'
-            completion-queue-count: 3
-            service-defaults:
-                task-processor: main-task-processor
-                middlewares: []
-
-
-
-        http-client:
-            fs-task-processor: main-task-processor
-
-        tests-control:
-            method: POST
-            path: /tests/{action}
-            skip-unregistered-testpoints: true
-            task_processor: main-task-processor
-            testpoint-timeout: 10s
-            testpoint-url: $mockserver/testpoint
-            throttling_enabled: false
-
-        logging:
-            fs-task-processor: fs-task-processor
-            loggers:
-                default:
-                    file_path: "@stderr"
-                    level: debug
-                    overflow_behavior: discard
-
-        dns-client:
-            fs-task-processor: fs-task-processor
-
-        server:
-            listener:
-                port: 8187
-                task_processor: main-task-processor
-
diff --git a/libraries/easy/functional_tests/sample/tests/test_grpc_reflection.py b/libraries/easy/functional_tests/sample/tests/test_grpc_reflection.py
deleted file mode 100644
index 4a7978bcb4d8..000000000000
--- a/libraries/easy/functional_tests/sample/tests/test_grpc_reflection.py
+++ /dev/null
@@ -1,20 +0,0 @@
-# /// [Functional test]
-async def test_hello_simple(service_client):
-    response = await service_client.get('/hello')
-    assert response.status == 200
-    assert 'text/plain' in response.headers['Content-Type']
-    assert response.text == 'Hello!\n'
-    # /// [Functional test]
-    
-async def disable_test_hello_base(service_client):
-    response = await service_client.get('/hello')
-    assert response.status == 200
-    assert 'text/plain' in response.headers['Content-Type']
-    assert response.text == 'Hello, unknown user!\n'
-    assert 'X-RequestId' not in response.headers.keys(), 'Unexpected header'
-
-    response = await service_client.get('/hello', params={'name': 'userver'})
-    assert response.status == 200
-    assert 'text/plain' in response.headers['Content-Type']
-    assert response.text == 'Hello, userver!\n'
-
diff --git a/libraries/easy/include/userver/easy.hpp b/libraries/easy/include/userver/easy.hpp
index a0413b89f39a..05f6321a1448 100644
--- a/libraries/easy/include/userver/easy.hpp
+++ b/libraries/easy/include/userver/easy.hpp
@@ -1,9 +1,13 @@
 #pragma once
 
+#include <functional>
+#include <string>
 #include <string_view>
 #include <unordered_map>
 
 #include <userver/components/component_list.hpp>
+#include <userver/server/http/http_request.hpp>
+#include <userver/server/request/request_context.hpp>
 
 USERVER_NAMESPACE_BEGIN
 
@@ -15,25 +19,24 @@ using RequestContext = server::request::RequestContext;
 
 class Http final {
 public:
-    using Callback = std::function<std::string(HttpRequest&);
+    using Callback = std::function<std::string(const HttpRequest&)>;
 
     Http(int argc, const char *const argv[]);
     ~Http();
 
     Http& Path(std::string_view path, Callback&& func);
 
-    int Run();
+    [[nodiscard]] int Run();
 
 private:
-    static std::unordered_map<std::string, Callback> functions_;
-
     void AddHandleConfig(std::string_view path);
 
     class Handle;
 
     const int argc_;
-    const char *const argv_[];
-    components::ComponentList component_list_ = MinimalServerComponentList();
+    const char *const* argv_;
+    std::string static_config_;
+    components::ComponentList component_list_;
 };
 
 }  // namespace easy
diff --git a/libraries/easy/library.yaml b/libraries/easy/library.yaml
deleted file mode 100644
index e8a02a8eb9c3..000000000000
--- a/libraries/easy/library.yaml
+++ /dev/null
@@ -1,10 +0,0 @@
-project-name: userver-grpc-reflection
-project-alt-names:
-  - yandex-userver-grpc-reflection
-description: library with reflection implementation
-
-maintainers:
-  - Common componets
-
-libraries:
-  - userver-core
diff --git a/libraries/easy/functional_tests/sample/CMakeLists.txt b/libraries/easy/samples/0_hello_world/CMakeLists.txt
similarity index 51%
rename from libraries/easy/functional_tests/sample/CMakeLists.txt
rename to libraries/easy/samples/0_hello_world/CMakeLists.txt
index 9cebfa72de26..536208b8e008 100644
--- a/libraries/easy/functional_tests/sample/CMakeLists.txt
+++ b/libraries/easy/samples/0_hello_world/CMakeLists.txt
@@ -1,6 +1,6 @@
-project(userver-easy-tests-sample CXX)
+project(userver-easy-samples-hello-world CXX)
 
 add_executable(${PROJECT_NAME} "main.cpp")
 target_link_libraries(${PROJECT_NAME} userver::easy)
 
-userver_testsuite_add_simple()
+userver_testsuite_add_simple(DUMP_CONFIG True)
diff --git a/libraries/easy/samples/0_hello_world/main.cpp b/libraries/easy/samples/0_hello_world/main.cpp
new file mode 100644
index 000000000000..50486291d0e5
--- /dev/null
+++ b/libraries/easy/samples/0_hello_world/main.cpp
@@ -0,0 +1,13 @@
+// Note: this is for the purposes of samples only
+#include <userver/utest/using_namespace_userver.hpp>
+
+#include <userver/easy.hpp>
+
+int main(int argc, char* argv[]) {
+    return easy::Http(argc, argv) //
+      .Path("/hello", [](const easy::HttpRequest& req) {
+        req.GetHttpResponse().SetContentType(http::content_type::kTextPlain);
+        return "Hello world";
+      }) //
+      .Run();
+}
diff --git a/libraries/easy/functional_tests/sample/tests/conftest.py b/libraries/easy/samples/0_hello_world/tests/conftest.py
similarity index 100%
rename from libraries/easy/functional_tests/sample/tests/conftest.py
rename to libraries/easy/samples/0_hello_world/tests/conftest.py
diff --git a/libraries/easy/samples/0_hello_world/tests/test_basic.py b/libraries/easy/samples/0_hello_world/tests/test_basic.py
new file mode 100644
index 000000000000..3ea76e627d03
--- /dev/null
+++ b/libraries/easy/samples/0_hello_world/tests/test_basic.py
@@ -0,0 +1,7 @@
+# /// [Functional test]
+async def test_hello_simple(service_client):
+    response = await service_client.get('/hello')
+    assert response.status == 200
+    assert 'text/plain' in response.headers['Content-Type']
+    assert response.text == 'Hello world'
+    # /// [Functional test]
diff --git a/libraries/easy/samples/CMakeLists.txt b/libraries/easy/samples/CMakeLists.txt
new file mode 100644
index 000000000000..a2b65677dfa7
--- /dev/null
+++ b/libraries/easy/samples/CMakeLists.txt
@@ -0,0 +1,6 @@
+project(userver-easy-samples CXX)
+
+add_custom_target(${PROJECT_NAME})
+
+add_subdirectory(0_hello_world)
+add_dependencies(${PROJECT_NAME} ${PROJECT_NAME}-hello-world)
diff --git a/libraries/easy/src/easy.cpp b/libraries/easy/src/easy.cpp
index 061bc6a07e1b..46cdcd8817aa 100644
--- a/libraries/easy/src/easy.cpp
+++ b/libraries/easy/src/easy.cpp
@@ -1,6 +1,13 @@
 #include <userver/easy.hpp>
 
+#include <fstream>
+
+#include <boost/program_options.hpp>
+
+#include <userver/components/minimal_server_component_list.hpp>
+#include <userver/components/run.hpp>
 #include <userver/server/handlers/http_handler_base.hpp>
+#include <userver/utils/daemon_run.hpp>
 
 USERVER_NAMESPACE_BEGIN
 
@@ -41,30 +48,34 @@ constexpr std::string_view kConfigHandlerTemplate = R"~(
             task_processor: main-task-processor  # Run it on CPU bound task processor
 )~";
 
+
+std::unordered_map<std::string, Http::Callback> g_http_functions_;
+
 }
 
-class Http::Handle final : public server::handlers::HttpHandlerBase, Function {
+class Http::Handle final : public server::handlers::HttpHandlerBase {
 public:
     Handle(const components::ComponentConfig& config, const components::ComponentContext& context):
       HttpHandlerBase(config, context),
-      callback_{Http::functions_[config.Name()]}
+      callback_{g_http_functions_[config.Name()]}
     {}
 
     std::string HandleRequestThrow(const HttpRequest& request, RequestContext&) const override {
         return callback_(request);
     }
 private:
-    Callback& callback_;
+    Http::Callback& callback_;
 };
 
-Http::Http(int argc, const char *const argv[]) : argc_{argc}, argv_{argv}, static_config_{kConfigBase} {}
+Http::Http(int argc, const char *const argv[]) : argc_{argc}, argv_{argv}, static_config_{kConfigBase},
+      component_list_{components::MinimalServerComponentList()} {}
 
 Http::~Http() {
-    functions_.clear();
+    g_http_functions_.clear();
 }
 
 Http& Http::Path(std::string_view path, Callback&& func) {
-    functions_.insert(path, std::move(func));
+    g_http_functions_.emplace(path, std::move(func));
     component_list_.Append<Handle>(path);
     AddHandleConfig(path);
 
@@ -72,7 +83,32 @@ Http& Http::Path(std::string_view path, Callback&& func) {
 }
 
 int Http::Run() {
-    return utils::DaemonMain(argc_, argv_, component_list_);
+    namespace po = boost::program_options;
+
+    po::variables_map vm;
+    po::options_description desc("Easy options");
+    std::string config_dump;
+
+    // clang-format off
+    desc.add_options()
+      ("dump-config", po::value(&config_dump), "path to dump the server config")
+    ;
+    // clang-format on
+
+    po::store(po::command_line_parser(argc_, argv_).options(desc).allow_unregistered().run(), vm);
+    po::notify(vm);
+
+    if (vm.count("dump-config")) {
+        std::ofstream(config_dump) << static_config_;
+        return 0;
+    }
+    
+    if (argc_ <= 1) {
+        components::Run(components::InMemoryConfig{static_config_}, component_list_);
+        return 0;
+    } else {
+        return utils::DaemonMain(argc_, argv_, component_list_);
+    } 
 }
 
 void Http::AddHandleConfig(std::string_view path) {
diff --git a/testsuite/pytest_plugins/pytest_userver/plugins/config.py b/testsuite/pytest_plugins/pytest_userver/plugins/config.py
index f39a4ce83617..4330ab3a02dc 100644
--- a/testsuite/pytest_plugins/pytest_userver/plugins/config.py
+++ b/testsuite/pytest_plugins/pytest_userver/plugins/config.py
@@ -7,6 +7,7 @@
 import logging
 import os
 import pathlib
+import subprocess
 import types
 import typing
 
@@ -97,13 +98,18 @@ def pytest_addoption(parser) -> None:
         type=pathlib.Path,
         help='Path to dynamic config fallback file.',
     )
+    group.addoption(
+        '--dump-config',
+        action='store_true',
+        help='Dump config from binary before running tests',
+    )
 
 
 # @endcond
 
 
 @pytest.fixture(scope='session')
-def service_config_path(pytestconfig) -> pathlib.Path:
+def service_config_path(pytestconfig, service_binary) -> pathlib.Path:
     """
     Returns the path to service.yaml file set by command line
     `--service-config` option.
@@ -112,6 +118,8 @@ def service_config_path(pytestconfig) -> pathlib.Path:
 
     @ingroup userver_testsuite_fixtures
     """
+    if pytestconfig.option.dump_config:
+        subprocess.run([service_binary, '--dump-config', pytestconfig.option.service_config]) 
     return pytestconfig.option.service_config
 
 

From 18d69bd86bc035d62e379e3ee7dab23b33dc3bd4 Mon Sep 17 00:00:00 2001
From: Antony Polukhin <antoshkka@gmail.com>
Date: Fri, 15 Nov 2024 13:18:59 +0300
Subject: [PATCH 03/19] start docs

---
 libraries/CMakeLists.txt                  | 1 +
 scripts/docs/en/index.md                  | 3 +++
 scripts/docs/en/userver/build/options.md  | 5 +++--
 scripts/docs/en/userver/libraries/easy.md | 3 +++
 4 files changed, 10 insertions(+), 2 deletions(-)
 create mode 100644 scripts/docs/en/userver/libraries/easy.md

diff --git a/libraries/CMakeLists.txt b/libraries/CMakeLists.txt
index 4c504f678e4d..b26f1ce10073 100644
--- a/libraries/CMakeLists.txt
+++ b/libraries/CMakeLists.txt
@@ -1,3 +1,4 @@
+option(USERVER_FEATURE_EASY "Build easy HTTP server library" "${USERVER_LIB_ENABLED_DEFAULT}")
 option(USERVER_FEATURE_S3API "Build S3 api client library" "${USERVER_LIB_ENABLED_DEFAULT}")
 option(USERVER_FEATURE_GRPC_REFLECTION "Build grpc reflection library" "${USERVER_LIB_ENABLED_DEFAULT}")
 
diff --git a/scripts/docs/en/index.md b/scripts/docs/en/index.md
index 8a6f8e042914..6393e5b175d9 100644
--- a/scripts/docs/en/index.md
+++ b/scripts/docs/en/index.md
@@ -152,6 +152,9 @@ are available at the
 
 ## Libraries
 
+### Easy
+* @ref scripts/docs/en/userver/libraries/easy.md
+
 ### S3 client
 * @ref scripts/docs/en/userver/libraries/s3api.md
 
diff --git a/scripts/docs/en/userver/build/options.md b/scripts/docs/en/userver/build/options.md
index efcd97eee6e0..55836d82f2d4 100644
--- a/scripts/docs/en/userver/build/options.md
+++ b/scripts/docs/en/userver/build/options.md
@@ -26,8 +26,9 @@ userver is split into multiple CMake libraries.
 | `userver::rocks`           | `USERVER_FEATURE_ROCKS`                           | `rocks`               | TODO                                               |
 | `userver::ydb`             | `USERVER_FEATURE_YDB`                             | `ydb`                 | @ref scripts/docs/en/userver/ydb.md                |
 | `userver::otlp`            | `USERVER_FEATURE_OTLP`                            | `otlp`                | @ref opentelemetry "OpenTelemetry Protocol"        |
-| `userver::s3api`            | `USERVER_FEATURE_S3API`                           | `s3api`               | @ref scripts/docs/en/userver/libraries/s3api.md    |
-| `userver::grpc-reflection`  | `USERVER_FEATURE_GRPC_REFLECTION`                 | `grpc-reflection`     | @ref scripts/docs/en/userver/libraries/grpc-reflection.md    |
+| `userver::easy`            | `USERVER_FEATURE_EASY`                            | `easy`                | @ref scripts/docs/en/userver/libraries/easy.md     |
+| `userver::s3api`           | `USERVER_FEATURE_S3API`                           | `s3api`               | @ref scripts/docs/en/userver/libraries/s3api.md    |
+| `userver::grpc-reflection` | `USERVER_FEATURE_GRPC_REFLECTION`                 | `grpc-reflection`     | @ref scripts/docs/en/userver/libraries/grpc-reflection.md    |
 
 Make sure to:
 
diff --git a/scripts/docs/en/userver/libraries/easy.md b/scripts/docs/en/userver/libraries/easy.md
new file mode 100644
index 000000000000..d623532a1626
--- /dev/null
+++ b/scripts/docs/en/userver/libraries/easy.md
@@ -0,0 +1,3 @@
+## Easy - library for single file prototyping
+
+TODO:

From 415e16891130095084b14ae33fd5de7ee251875d Mon Sep 17 00:00:00 2001
From: Antony Polukhin <antoshkka@gmail.com>
Date: Fri, 15 Nov 2024 13:46:33 +0300
Subject: [PATCH 04/19] minor tweaks

---
 libraries/easy/include/userver/easy.hpp       |  3 --
 libraries/easy/samples/0_hello_world/main.cpp |  5 ++-
 libraries/easy/src/easy.cpp                   | 33 +++++++++----------
 3 files changed, 18 insertions(+), 23 deletions(-)

diff --git a/libraries/easy/include/userver/easy.hpp b/libraries/easy/include/userver/easy.hpp
index 05f6321a1448..588a2c7b307c 100644
--- a/libraries/easy/include/userver/easy.hpp
+++ b/libraries/easy/include/userver/easy.hpp
@@ -25,9 +25,6 @@ class Http final {
     ~Http();
 
     Http& Path(std::string_view path, Callback&& func);
-
-    [[nodiscard]] int Run();
-
 private:
     void AddHandleConfig(std::string_view path);
 
diff --git a/libraries/easy/samples/0_hello_world/main.cpp b/libraries/easy/samples/0_hello_world/main.cpp
index 50486291d0e5..65c52a68ea79 100644
--- a/libraries/easy/samples/0_hello_world/main.cpp
+++ b/libraries/easy/samples/0_hello_world/main.cpp
@@ -4,10 +4,9 @@
 #include <userver/easy.hpp>
 
 int main(int argc, char* argv[]) {
-    return easy::Http(argc, argv) //
+    easy::Http(argc, argv) //
       .Path("/hello", [](const easy::HttpRequest& req) {
         req.GetHttpResponse().SetContentType(http::content_type::kTextPlain);
         return "Hello world";
-      }) //
-      .Run();
+      });
 }
diff --git a/libraries/easy/src/easy.cpp b/libraries/easy/src/easy.cpp
index 46cdcd8817aa..eef795e3fb3e 100644
--- a/libraries/easy/src/easy.cpp
+++ b/libraries/easy/src/easy.cpp
@@ -51,7 +51,7 @@ constexpr std::string_view kConfigHandlerTemplate = R"~(
 
 std::unordered_map<std::string, Http::Callback> g_http_functions_;
 
-}
+}  // anonymous namespace
 
 class Http::Handle final : public server::handlers::HttpHandlerBase {
 public:
@@ -71,18 +71,6 @@ Http::Http(int argc, const char *const argv[]) : argc_{argc}, argv_{argv}, stati
       component_list_{components::MinimalServerComponentList()} {}
 
 Http::~Http() {
-    g_http_functions_.clear();
-}
-
-Http& Http::Path(std::string_view path, Callback&& func) {
-    g_http_functions_.emplace(path, std::move(func));
-    component_list_.Append<Handle>(path);
-    AddHandleConfig(path);
-
-    return *this;
-}
-
-int Http::Run() {
     namespace po = boost::program_options;
 
     po::variables_map vm;
@@ -100,15 +88,26 @@ int Http::Run() {
 
     if (vm.count("dump-config")) {
         std::ofstream(config_dump) << static_config_;
-        return 0;
+        return;
     }
     
     if (argc_ <= 1) {
         components::Run(components::InMemoryConfig{static_config_}, component_list_);
-        return 0;
+        return;
     } else {
-        return utils::DaemonMain(argc_, argv_, component_list_);
-    } 
+        const auto ret = utils::DaemonMain(argc_, argv_, component_list_);
+        if (ret != 0) {
+            std::exit(ret);
+        }
+    }
+}
+
+Http& Http::Path(std::string_view path, Callback&& func) {
+    g_http_functions_.emplace(path, std::move(func));
+    component_list_.Append<Handle>(path);
+    AddHandleConfig(path);
+
+    return *this;
 }
 
 void Http::AddHandleConfig(std::string_view path) {

From e5ae62ca80dde8acbab5728ce901177d842f099c Mon Sep 17 00:00:00 2001
From: Antony Polukhin <antoshkka@gmail.com>
Date: Fri, 15 Nov 2024 15:28:23 +0300
Subject: [PATCH 05/19] more tests

---
 libraries/easy/include/userver/easy.hpp              |  6 +++++-
 libraries/easy/samples/0_hello_world/main.cpp        | 10 ++++++++--
 .../easy/samples/0_hello_world/tests/test_basic.py   | 12 ++++++++++++
 libraries/easy/src/easy.cpp                          | 11 ++++++++++-
 4 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/libraries/easy/include/userver/easy.hpp b/libraries/easy/include/userver/easy.hpp
index 588a2c7b307c..819e7665c148 100644
--- a/libraries/easy/include/userver/easy.hpp
+++ b/libraries/easy/include/userver/easy.hpp
@@ -6,6 +6,7 @@
 #include <unordered_map>
 
 #include <userver/components/component_list.hpp>
+#include <userver/http/content_type.hpp>
 #include <userver/server/http/http_request.hpp>
 #include <userver/server/request/request_context.hpp>
 
@@ -24,7 +25,10 @@ class Http final {
     Http(int argc, const char *const argv[]);
     ~Http();
 
-    Http& Path(std::string_view path, Callback&& func);
+    
+    Http& DefaultContentType(http::ContentType content_type);
+
+    Http& Route(std::string_view path, Callback&& func);
 private:
     void AddHandleConfig(std::string_view path);
 
diff --git a/libraries/easy/samples/0_hello_world/main.cpp b/libraries/easy/samples/0_hello_world/main.cpp
index 65c52a68ea79..34e890a1259b 100644
--- a/libraries/easy/samples/0_hello_world/main.cpp
+++ b/libraries/easy/samples/0_hello_world/main.cpp
@@ -5,8 +5,14 @@
 
 int main(int argc, char* argv[]) {
     easy::Http(argc, argv) //
-      .Path("/hello", [](const easy::HttpRequest& req) {
-        req.GetHttpResponse().SetContentType(http::content_type::kTextPlain);
+      .DefaultContentType(http::content_type::kTextPlain)
+      .Route("/hello", [](const easy::HttpRequest& req) {
         return "Hello world";
+      })
+      .Route("/hello/to/{user}", [](const easy::HttpRequest& req) {
+        return "Hello, " + req.GetPathArg("user");
+      })
+      .Route("/hi", [](const easy::HttpRequest& req) {
+        return "Hi, " + req.GetArg("name");
       });
 }
diff --git a/libraries/easy/samples/0_hello_world/tests/test_basic.py b/libraries/easy/samples/0_hello_world/tests/test_basic.py
index 3ea76e627d03..696228ccff0c 100644
--- a/libraries/easy/samples/0_hello_world/tests/test_basic.py
+++ b/libraries/easy/samples/0_hello_world/tests/test_basic.py
@@ -5,3 +5,15 @@ async def test_hello_simple(service_client):
     assert 'text/plain' in response.headers['Content-Type']
     assert response.text == 'Hello world'
     # /// [Functional test]
+
+async def test_hello_to(service_client):
+    response = await service_client.get('/hello/to/flusk')
+    assert response.status == 200
+    assert 'text/plain' in response.headers['Content-Type']
+    assert response.text == 'Hello, flusk'
+
+async def test_hi(service_client):
+    response = await service_client.get('/hi?name=pal')
+    assert response.status == 200
+    assert 'text/plain' in response.headers['Content-Type']
+    assert response.text == 'Hi, pal'
diff --git a/libraries/easy/src/easy.cpp b/libraries/easy/src/easy.cpp
index eef795e3fb3e..4c412bd67fd7 100644
--- a/libraries/easy/src/easy.cpp
+++ b/libraries/easy/src/easy.cpp
@@ -50,6 +50,7 @@ constexpr std::string_view kConfigHandlerTemplate = R"~(
 
 
 std::unordered_map<std::string, Http::Callback> g_http_functions_;
+std::optional<http::ContentType> default_content_type_;
 
 }  // anonymous namespace
 
@@ -61,6 +62,9 @@ class Http::Handle final : public server::handlers::HttpHandlerBase {
     {}
 
     std::string HandleRequestThrow(const HttpRequest& request, RequestContext&) const override {
+        if (default_content_type_) {
+            request.GetHttpResponse().SetContentType(*default_content_type_);
+        }
         return callback_(request);
     }
 private:
@@ -102,7 +106,12 @@ Http::~Http() {
     }
 }
 
-Http& Http::Path(std::string_view path, Callback&& func) {
+Http& Http::DefaultContentType(http::ContentType content_type) {
+    default_content_type_ = content_type;
+    return *this;
+}
+
+Http& Http::Route(std::string_view path, Callback&& func) {
     g_http_functions_.emplace(path, std::move(func));
     component_list_.Append<Handle>(path);
     AddHandleConfig(path);

From e8e6b1ff4a511478df722cbfb390b4bd16b99eba Mon Sep 17 00:00:00 2001
From: Antony Polukhin <antoshkka@gmail.com>
Date: Fri, 15 Nov 2024 17:49:19 +0300
Subject: [PATCH 06/19] move towards Dependency

---
 libraries/easy/include/userver/easy.hpp       | 65 ++++++++++++++++++-
 libraries/easy/samples/0_hello_world/main.cpp |  2 +-
 libraries/easy/src/easy.cpp                   | 34 ++++++++--
 3 files changed, 93 insertions(+), 8 deletions(-)

diff --git a/libraries/easy/include/userver/easy.hpp b/libraries/easy/include/userver/easy.hpp
index 819e7665c148..c3aa136668fd 100644
--- a/libraries/easy/include/userver/easy.hpp
+++ b/libraries/easy/include/userver/easy.hpp
@@ -6,10 +6,13 @@
 #include <unordered_map>
 
 #include <userver/components/component_list.hpp>
+#include <userver/components/component_base.hpp>
 #include <userver/http/content_type.hpp>
 #include <userver/server/http/http_request.hpp>
 #include <userver/server/request/request_context.hpp>
 
+#include <userver/storages/postgres/cluster.hpp>
+
 USERVER_NAMESPACE_BEGIN
 
 /// @brief Top namespace for `easy` library
@@ -18,13 +21,39 @@ namespace easy {
 using HttpRequest = server::http::HttpRequest;
 using RequestContext = server::request::RequestContext;
 
-class Http final {
+class DependenciesBase: public components::ComponentBase {
 public:
-    using Callback = std::function<std::string(const HttpRequest&)>;
+    static constexpr std::string_view kName = "easy-dependencies";
+    using components::ComponentBase::ComponentBase;
+    virtual ~DependenciesBase();
+};
+
+class Callback {
+public:
+    using Underlying = std::function<std::string(const HttpRequest&, const DependenciesBase&)>;
+
+    template <class Function>
+    Callback(Function func) {
+        if constexpr (std::is_invocable_r_v<std::string, Function, const HttpRequest&, const DependenciesBase&>) {
+            func_ = std::move(func);
+        } else {
+          static_assert(std::is_invocable_r_v<std::string, Function, const HttpRequest&>);
+          func_ = [f = std::move(func)](const HttpRequest& req, const DependenciesBase&) {
+            return f(req);
+          };
+        }
+    }
+
+    Underlying Extract() && noexcept { return std::move(func_); }
 
+private:
+    std::function<std::string(const HttpRequest&, const DependenciesBase&)> func_;
+};
+
+class Http final {
+public:
     Http(int argc, const char *const argv[]);
     ~Http();
-
     
     Http& DefaultContentType(http::ContentType content_type);
 
@@ -40,6 +69,36 @@ class Http final {
     components::ComponentList component_list_;
 };
 
+///
+
+template <class Dependency>
+class CallbackWith : public Callback {
+public:
+    using Callback::Callback;
+
+    CallbackWith(std::function<std::string(const HttpRequest&, const Dependency&)> func)
+        : Callback([f = std::move(func)](const HttpRequest& req, const DependenciesBase& deps) {
+            return f(req, static_cast<Dependency&>(deps));
+        })
+    {}
+};
+
+class Postgres : public DependenciesBase {
+public:
+    Postgres(const components::ComponentConfig& config, const components::ComponentContext& context);
+
+    storages::postgres::Cluster& pg() const noexcept { return *pg_cluster_; }
+
+private:
+    storages::postgres::ClusterPtr pg_cluster_;
+};
+
 }  // namespace easy
 
+template <>
+inline constexpr auto components::kConfigFileMode<easy::DependenciesBase> = ConfigFileMode::kNotRequired;
+
+template <>
+inline constexpr auto components::kConfigFileMode<easy::Postgres> = ConfigFileMode::kNotRequired;
+
 USERVER_NAMESPACE_END
diff --git a/libraries/easy/samples/0_hello_world/main.cpp b/libraries/easy/samples/0_hello_world/main.cpp
index 34e890a1259b..c44b3ab6c10b 100644
--- a/libraries/easy/samples/0_hello_world/main.cpp
+++ b/libraries/easy/samples/0_hello_world/main.cpp
@@ -6,7 +6,7 @@
 int main(int argc, char* argv[]) {
     easy::Http(argc, argv) //
       .DefaultContentType(http::content_type::kTextPlain)
-      .Route("/hello", [](const easy::HttpRequest& req) {
+      .Route("/hello", [](const easy::HttpRequest& /*req*/) {
         return "Hello world";
       })
       .Route("/hello/to/{user}", [](const easy::HttpRequest& req) {
diff --git a/libraries/easy/src/easy.cpp b/libraries/easy/src/easy.cpp
index 4c412bd67fd7..aa311c5d3b6c 100644
--- a/libraries/easy/src/easy.cpp
+++ b/libraries/easy/src/easy.cpp
@@ -6,9 +6,12 @@
 
 #include <userver/components/minimal_server_component_list.hpp>
 #include <userver/components/run.hpp>
+#include <userver/components/component_context.hpp>
 #include <userver/server/handlers/http_handler_base.hpp>
 #include <userver/utils/daemon_run.hpp>
 
+#include <userver/storages/postgres/component.hpp>
+
 USERVER_NAMESPACE_BEGIN
 
 namespace easy {
@@ -48,16 +51,33 @@ constexpr std::string_view kConfigHandlerTemplate = R"~(
             task_processor: main-task-processor  # Run it on CPU bound task processor
 )~";
 
+class EmptyDeps final : public DependenciesBase {
+    using DependenciesBase::DependenciesBase;
+};
+
+const DependenciesBase& GetDeps(const components::ComponentConfig& config, const components::ComponentContext& context) {
+    const auto* deps = context.FindComponentOptional<DependenciesBase>();
+    if (deps) {
+        return *deps;
+    }
+
+    static const EmptyDeps empty{config, context};
+    return empty;
+}
 
-std::unordered_map<std::string, Http::Callback> g_http_functions_;
+std::unordered_map<std::string, Callback::Underlying> g_http_functions_;
 std::optional<http::ContentType> default_content_type_;
 
 }  // anonymous namespace
 
+
+DependenciesBase::~DependenciesBase() = default;
+
 class Http::Handle final : public server::handlers::HttpHandlerBase {
 public:
     Handle(const components::ComponentConfig& config, const components::ComponentContext& context):
       HttpHandlerBase(config, context),
+      deps_{GetDeps(config, context)},
       callback_{g_http_functions_[config.Name()]}
     {}
 
@@ -65,10 +85,12 @@ class Http::Handle final : public server::handlers::HttpHandlerBase {
         if (default_content_type_) {
             request.GetHttpResponse().SetContentType(*default_content_type_);
         }
-        return callback_(request);
+        return callback_(request, deps_);
     }
+
 private:
-    Http::Callback& callback_;
+    const DependenciesBase& deps_;
+    Callback::Underlying& callback_;
 };
 
 Http::Http(int argc, const char *const argv[]) : argc_{argc}, argv_{argv}, static_config_{kConfigBase},
@@ -112,7 +134,7 @@ Http& Http::DefaultContentType(http::ContentType content_type) {
 }
 
 Http& Http::Route(std::string_view path, Callback&& func) {
-    g_http_functions_.emplace(path, std::move(func));
+    g_http_functions_.emplace(path, std::move(func).Extract());
     component_list_.Append<Handle>(path);
     AddHandleConfig(path);
 
@@ -123,6 +145,10 @@ void Http::AddHandleConfig(std::string_view path) {
     static_config_ += fmt::format(kConfigHandlerTemplate, path);
 }
 
+
+Postgres::Postgres(const components::ComponentConfig& config, const components::ComponentContext& context)
+: DependenciesBase{config, context}, pg_cluster_(context.FindComponent<components::Postgres>("key-value-database").GetCluster()) {}
+
 }  // namespace easy
 
 USERVER_NAMESPACE_END

From ad2bfd28a54ae624ab38c5fd8b9bc46987b7633e Mon Sep 17 00:00:00 2001
From: Antony Polukhin <antoshkka@gmail.com>
Date: Fri, 15 Nov 2024 19:20:14 +0300
Subject: [PATCH 07/19] WIP

---
 libraries/easy/include/userver/easy.hpp       | 94 ++++++++++++-------
 libraries/easy/samples/0_hello_world/main.cpp |  2 +-
 libraries/easy/src/easy.cpp                   | 25 ++---
 3 files changed, 76 insertions(+), 45 deletions(-)

diff --git a/libraries/easy/include/userver/easy.hpp b/libraries/easy/include/userver/easy.hpp
index c3aa136668fd..5ac07b4df8dd 100644
--- a/libraries/easy/include/userver/easy.hpp
+++ b/libraries/easy/include/userver/easy.hpp
@@ -28,38 +28,26 @@ class DependenciesBase: public components::ComponentBase {
     virtual ~DependenciesBase();
 };
 
-class Callback {
-public:
-    using Underlying = std::function<std::string(const HttpRequest&, const DependenciesBase&)>;
-
-    template <class Function>
-    Callback(Function func) {
-        if constexpr (std::is_invocable_r_v<std::string, Function, const HttpRequest&, const DependenciesBase&>) {
-            func_ = std::move(func);
-        } else {
-          static_assert(std::is_invocable_r_v<std::string, Function, const HttpRequest&>);
-          func_ = [f = std::move(func)](const HttpRequest& req, const DependenciesBase&) {
-            return f(req);
-          };
-        }
-    }
+namespace impl {
 
-    Underlying Extract() && noexcept { return std::move(func_); }
+using UnderlyingCallback = std::function<std::string(const HttpRequest&, const DependenciesBase&)>;
 
-private:
-    std::function<std::string(const HttpRequest&, const DependenciesBase&)> func_;
-};
+struct AggressiveUnicorn; // Do not unleash
+
+template <class Dependency>
+using ConstDependencyRef = std::conditional_t<std::is_void_v<Dependency>, AggressiveUnicorn, Dependency> const&; 
 
-class Http final {
+class HttpBase {
 public:
-    Http(int argc, const char *const argv[]);
-    ~Http();
+    HttpBase(int argc, const char *const argv[]);
+    ~HttpBase();
     
-    Http& DefaultContentType(http::ContentType content_type);
+    void DefaultContentType(http::ContentType content_type);
+    void Route(std::string_view path, UnderlyingCallback&& func);
 
-    Http& Route(std::string_view path, Callback&& func);
 private:
     void AddHandleConfig(std::string_view path);
+    void AddDependencyConfig(std::string_view config);
 
     class Handle;
 
@@ -69,20 +57,62 @@ class Http final {
     components::ComponentList component_list_;
 };
 
-///
+}
 
 template <class Dependency>
-class CallbackWith : public Callback {
+class Configurator;
+
+template <>
+class Configurator<void> {};
+
+template <class Dependency = void>
+class HttpWith final : public Configurator<Dependency> {
 public:
-    using Callback::Callback;
+    class Callback {
+    public:
+        template <class Function>
+        Callback(Function func);
 
-    CallbackWith(std::function<std::string(const HttpRequest&, const Dependency&)> func)
-        : Callback([f = std::move(func)](const HttpRequest& req, const DependenciesBase& deps) {
-            return f(req, static_cast<Dependency&>(deps));
-        })
-    {}
+        auto Extract() && noexcept { return std::move(func_); }
+
+    private:
+        impl::UnderlyingCallback func_;
+    };
+
+    HttpWith(int argc, const char *const argv[]) : impl_(argc, argv) {}
+    ~HttpWith() = default;
+    
+    HttpWith& DefaultContentType(http::ContentType content_type) {
+        impl_.DefaultContentType(content_type);
+        return *this;
+    }
+
+    HttpWith& Route(std::string_view path, Callback&& func) {
+        impl_.Route(path, std::move(func).Extract());
+        return *this;
+    }
+
+private:
+    impl::HttpBase impl_;
 };
 
+template <class Dependency>
+template <class Function>
+HttpWith<Dependency>::Callback::Callback(Function func) {
+    if constexpr (std::is_invocable_r_v<std::string, Function, const HttpRequest&, const DependenciesBase&>) {
+        func_ = std::move(func);
+    } else if constexpr (std::is_invocable_r_v<std::string, Function, const HttpRequest&, impl::ConstDependencyRef<Dependency> >) {
+        func_ = [f = std::move(func)](const HttpRequest& req, const DependenciesBase& deps) {
+            return f(req, static_cast<Dependency&>(deps));
+        };
+    } else {
+      static_assert(std::is_invocable_r_v<std::string, Function, const HttpRequest&>);
+      func_ = [f = std::move(func)](const HttpRequest& req, const DependenciesBase&) {
+        return f(req);
+      };
+    }
+}
+
 class Postgres : public DependenciesBase {
 public:
     Postgres(const components::ComponentConfig& config, const components::ComponentContext& context);
diff --git a/libraries/easy/samples/0_hello_world/main.cpp b/libraries/easy/samples/0_hello_world/main.cpp
index c44b3ab6c10b..05fec54e35ee 100644
--- a/libraries/easy/samples/0_hello_world/main.cpp
+++ b/libraries/easy/samples/0_hello_world/main.cpp
@@ -4,7 +4,7 @@
 #include <userver/easy.hpp>
 
 int main(int argc, char* argv[]) {
-    easy::Http(argc, argv) //
+    easy::HttpWith(argc, argv) //
       .DefaultContentType(http::content_type::kTextPlain)
       .Route("/hello", [](const easy::HttpRequest& /*req*/) {
         return "Hello world";
diff --git a/libraries/easy/src/easy.cpp b/libraries/easy/src/easy.cpp
index aa311c5d3b6c..ea9923bd4277 100644
--- a/libraries/easy/src/easy.cpp
+++ b/libraries/easy/src/easy.cpp
@@ -65,7 +65,7 @@ const DependenciesBase& GetDeps(const components::ComponentConfig& config, const
     return empty;
 }
 
-std::unordered_map<std::string, Callback::Underlying> g_http_functions_;
+std::unordered_map<std::string, impl::UnderlyingCallback> g_http_functions_;
 std::optional<http::ContentType> default_content_type_;
 
 }  // anonymous namespace
@@ -73,7 +73,9 @@ std::optional<http::ContentType> default_content_type_;
 
 DependenciesBase::~DependenciesBase() = default;
 
-class Http::Handle final : public server::handlers::HttpHandlerBase {
+namespace impl {
+
+class HttpBase::Handle final : public server::handlers::HttpHandlerBase {
 public:
     Handle(const components::ComponentConfig& config, const components::ComponentContext& context):
       HttpHandlerBase(config, context),
@@ -90,13 +92,13 @@ class Http::Handle final : public server::handlers::HttpHandlerBase {
 
 private:
     const DependenciesBase& deps_;
-    Callback::Underlying& callback_;
+    impl::UnderlyingCallback& callback_;
 };
 
-Http::Http(int argc, const char *const argv[]) : argc_{argc}, argv_{argv}, static_config_{kConfigBase},
+HttpBase::HttpBase(int argc, const char *const argv[]) : argc_{argc}, argv_{argv}, static_config_{kConfigBase},
       component_list_{components::MinimalServerComponentList()} {}
 
-Http::~Http() {
+HttpBase::~HttpBase() {
     namespace po = boost::program_options;
 
     po::variables_map vm;
@@ -128,23 +130,22 @@ Http::~Http() {
     }
 }
 
-Http& Http::DefaultContentType(http::ContentType content_type) {
+void HttpBase::DefaultContentType(http::ContentType content_type) {
     default_content_type_ = content_type;
-    return *this;
 }
 
-Http& Http::Route(std::string_view path, Callback&& func) {
-    g_http_functions_.emplace(path, std::move(func).Extract());
+void HttpBase::Route(std::string_view path, UnderlyingCallback&& func) {
+    g_http_functions_.emplace(path, std::move(func));
     component_list_.Append<Handle>(path);
     AddHandleConfig(path);
-
-    return *this;
 }
 
-void Http::AddHandleConfig(std::string_view path) {
+void HttpBase::AddHandleConfig(std::string_view path) {
     static_config_ += fmt::format(kConfigHandlerTemplate, path);
 }
 
+}  // namespace impl
+
 
 Postgres::Postgres(const components::ComponentConfig& config, const components::ComponentContext& context)
 : DependenciesBase{config, context}, pg_cluster_(context.FindComponent<components::Postgres>("key-value-database").GetCluster()) {}

From 25eb3d6233e1915d0053549f6c9941a02512f234 Mon Sep 17 00:00:00 2001
From: Antony Polukhin <antoshkka@gmail.com>
Date: Fri, 15 Nov 2024 20:21:37 +0300
Subject: [PATCH 08/19] WIP

---
 libraries/easy/include/userver/easy.hpp       | 62 +++++++++++++++----
 libraries/easy/samples/0_hello_world/main.cpp |  2 +-
 .../samples/0_hello_world/tests/conftest.py   | 20 ++++--
 libraries/easy/src/easy.cpp                   | 41 +++++++++---
 4 files changed, 101 insertions(+), 24 deletions(-)

diff --git a/libraries/easy/include/userver/easy.hpp b/libraries/easy/include/userver/easy.hpp
index 5ac07b4df8dd..573858d46e8d 100644
--- a/libraries/easy/include/userver/easy.hpp
+++ b/libraries/easy/include/userver/easy.hpp
@@ -45,9 +45,18 @@ class HttpBase {
     void DefaultContentType(http::ContentType content_type);
     void Route(std::string_view path, UnderlyingCallback&& func);
 
+    void AddComponentsConfig(std::string_view config);
+
+    template <class Component>
+    void AppendComponent(std::string_view name) {
+        component_list_.Append<Component>(name);
+    }
+    template <class Component>
+    void AppendComponent() {
+        component_list_.Append<Component>();
+    }
 private:
     void AddHandleConfig(std::string_view path);
-    void AddDependencyConfig(std::string_view config);
 
     class Handle;
 
@@ -59,14 +68,22 @@ class HttpBase {
 
 }
 
-template <class Dependency>
-class Configurator;
+template <class Dependency = void>
+class HttpWith;
 
-template <>
-class Configurator<void> {};
+inline void DependenciesRegistration(HttpWith<void>&) {}
 
-template <class Dependency = void>
-class HttpWith final : public Configurator<Dependency> {
+template <class T>
+inline void DependenciesRegistration(HttpWith<T>&) {
+    static_assert(sizeof(T) && false, "Define `void DependenciesRegistration(HttpWith<T>& app)` "
+        "in the namespace of the your type `T` to automatically add required configurations and "
+        "components to the `app` for your dependences type `T`.  For example:"
+        "void DependenciesRegistration(HttpWith<MyDeps>& app) { app.AppendComponent<MyComponent>(); }"
+    );
+}
+
+template <class Dependency>
+class HttpWith final {
 public:
     class Callback {
     public:
@@ -80,7 +97,10 @@ class HttpWith final : public Configurator<Dependency> {
     };
 
     HttpWith(int argc, const char *const argv[]) : impl_(argc, argv) {}
-    ~HttpWith() = default;
+
+    ~HttpWith() {
+        DependenciesRegistration(*this);  // ADL is intentional
+    }
     
     HttpWith& DefaultContentType(http::ContentType content_type) {
         impl_.DefaultContentType(content_type);
@@ -92,6 +112,23 @@ class HttpWith final : public Configurator<Dependency> {
         return *this;
     }
 
+    HttpWith& AddComponentsConfig(std::string_view config) {
+        impl_.AddComponentsConfig(config);
+        return *this;
+    }
+
+    template <class Component>
+    HttpWith& AppendComponent(std::string_view name) {
+        impl_.AppendComponent<Component>(name);
+        return *this;
+    }
+
+    template <class Component>
+    HttpWith& AppendComponent() {
+        impl_.AppendComponent<Component>();
+        return *this;
+    }
+
 private:
     impl::HttpBase impl_;
 };
@@ -113,9 +150,9 @@ HttpWith<Dependency>::Callback::Callback(Function func) {
     }
 }
 
-class Postgres : public DependenciesBase {
+class PgDep : public DependenciesBase {
 public:
-    Postgres(const components::ComponentConfig& config, const components::ComponentContext& context);
+    PgDep(const components::ComponentConfig& config, const components::ComponentContext& context);
 
     storages::postgres::Cluster& pg() const noexcept { return *pg_cluster_; }
 
@@ -123,12 +160,15 @@ class Postgres : public DependenciesBase {
     storages::postgres::ClusterPtr pg_cluster_;
 };
 
+void DependenciesRegistration(HttpWith<PgDep>& app);
+
+
 }  // namespace easy
 
 template <>
 inline constexpr auto components::kConfigFileMode<easy::DependenciesBase> = ConfigFileMode::kNotRequired;
 
 template <>
-inline constexpr auto components::kConfigFileMode<easy::Postgres> = ConfigFileMode::kNotRequired;
+inline constexpr auto components::kConfigFileMode<easy::PgDep> = ConfigFileMode::kNotRequired;
 
 USERVER_NAMESPACE_END
diff --git a/libraries/easy/samples/0_hello_world/main.cpp b/libraries/easy/samples/0_hello_world/main.cpp
index 05fec54e35ee..807bc59222ed 100644
--- a/libraries/easy/samples/0_hello_world/main.cpp
+++ b/libraries/easy/samples/0_hello_world/main.cpp
@@ -4,7 +4,7 @@
 #include <userver/easy.hpp>
 
 int main(int argc, char* argv[]) {
-    easy::HttpWith(argc, argv) //
+    easy::HttpWith<easy::PgDep>(argc, argv) //
       .DefaultContentType(http::content_type::kTextPlain)
       .Route("/hello", [](const easy::HttpRequest& /*req*/) {
         return "Hello world";
diff --git a/libraries/easy/samples/0_hello_world/tests/conftest.py b/libraries/easy/samples/0_hello_world/tests/conftest.py
index 41ffab87fc60..0c2173fcc3cc 100644
--- a/libraries/easy/samples/0_hello_world/tests/conftest.py
+++ b/libraries/easy/samples/0_hello_world/tests/conftest.py
@@ -1,4 +1,16 @@
-# /// [registration]
-# Adding a plugin from userver/testsuite/pytest_plugins/
-pytest_plugins = ['pytest_userver.plugins.core']
-# /// [registration]
+import pytest
+
+from testsuite.databases.pgsql import discover
+
+pytest_plugins = ['pytest_userver.plugins.postgresql']
+
+@pytest.fixture(scope='session')
+def pgsql_local(service_source_dir, pgsql_local_create):
+    with open(service_source_dir.joinpath('schemas/postgresql/1.sql'), 'w') as f:
+        f.write('CREATE TABLE FOO(int);')
+
+    databases = discover.find_schemas(
+        'admin', [service_source_dir.joinpath('schemas/postgresql')],
+    )
+    return pgsql_local_create(list(databases.values()))
+
diff --git a/libraries/easy/src/easy.cpp b/libraries/easy/src/easy.cpp
index ea9923bd4277..75c9bd6a206c 100644
--- a/libraries/easy/src/easy.cpp
+++ b/libraries/easy/src/easy.cpp
@@ -3,13 +3,15 @@
 #include <fstream>
 
 #include <boost/program_options.hpp>
+#include <boost/algorithm/string/replace.hpp>
 
 #include <userver/components/minimal_server_component_list.hpp>
 #include <userver/components/run.hpp>
 #include <userver/components/component_context.hpp>
 #include <userver/server/handlers/http_handler_base.hpp>
+#include <userver/testsuite/testsuite_support.hpp>
+#include <userver/clients/dns/component.hpp>
 #include <userver/utils/daemon_run.hpp>
-
 #include <userver/storages/postgres/component.hpp>
 
 USERVER_NAMESPACE_BEGIN
@@ -45,10 +47,10 @@ constexpr std::string_view kConfigBase = R"~(
 
 
 constexpr std::string_view kConfigHandlerTemplate = R"~(
-        {0}:
-            path: {0}                  # Registering handler by URL '{0}'.
-            method: GET,POST              # It will only reply to GET (HEAD) and POST requests.
-            task_processor: main-task-processor  # Run it on CPU bound task processor
+{0}:
+    path: {0}                  # Registering handler by URL '{0}'.
+    method: GET,POST              # It will only reply to GET (HEAD) and POST requests.
+    task_processor: main-task-processor  # Run it on CPU bound task processor
 )~";
 
 class EmptyDeps final : public DependenciesBase {
@@ -141,14 +143,37 @@ void HttpBase::Route(std::string_view path, UnderlyingCallback&& func) {
 }
 
 void HttpBase::AddHandleConfig(std::string_view path) {
-    static_config_ += fmt::format(kConfigHandlerTemplate, path);
+    AddComponentsConfig(fmt::format(kConfigHandlerTemplate, path));
+}
+
+void HttpBase::AddComponentsConfig(std::string_view config) {
+    static_config_ += boost::algorithm::replace_all_copy(std::string{config}, "\n", "\n        ");
 }
 
 }  // namespace impl
 
 
-Postgres::Postgres(const components::ComponentConfig& config, const components::ComponentContext& context)
-: DependenciesBase{config, context}, pg_cluster_(context.FindComponent<components::Postgres>("key-value-database").GetCluster()) {}
+PgDep::PgDep(const components::ComponentConfig& config, const components::ComponentContext& context)
+: DependenciesBase{config, context}, pg_cluster_(context.FindComponent<components::Postgres>("postgres").GetCluster()) {}
+
+void DependenciesRegistration(HttpWith<PgDep>& app) {
+    app.AddComponentsConfig(R"~(
+postgres:
+    dbconnection#env: POSTGRESQL
+    dbconnection#fallback: 'postgresql://testsuite@localhost:15433/postgres'
+    blocking_task_processor: fs-task-processor
+    dns_resolver: async
+
+testsuite-support:
+
+dns-client:
+    fs-task-processor: fs-task-processor
+)~");
+
+    app.AppendComponent<components::Postgres>("postgres");
+    app.AppendComponent<components::TestsuiteSupport>();
+    app.AppendComponent<clients::dns::Component>();
+}
 
 }  // namespace easy
 

From d71efb0a79f5d8081b435e82de66193e075e0f6a Mon Sep 17 00:00:00 2001
From: Antony Polukhin <antoshkka@gmail.com>
Date: Sun, 17 Nov 2024 11:42:15 +0300
Subject: [PATCH 09/19] WIP

---
 cmake/install/userver-easy-config.cmake        |  5 +----
 libraries/easy/include/userver/easy.hpp        | 10 +++++++++-
 libraries/easy/samples/0_hello_world/main.cpp  | 18 ++++++++++++++++++
 .../samples/0_hello_world/tests/conftest.py    | 18 ++++++++++--------
 libraries/easy/src/easy.cpp                    |  8 +++++++-
 5 files changed, 45 insertions(+), 14 deletions(-)

diff --git a/cmake/install/userver-easy-config.cmake b/cmake/install/userver-easy-config.cmake
index 40caf93a1c06..3f8b8775bcdb 100644
--- a/cmake/install/userver-easy-config.cmake
+++ b/cmake/install/userver-easy-config.cmake
@@ -4,10 +4,7 @@ if(userver_easy_FOUND)
   return()
 endif()
 
-find_package(userver REQUIRED COMPONENTS
-    core
-    postgresql
-)
+find_package(userver REQUIRED COMPONENTS postgresql)
 
 set(userver_easy_FOUND TRUE)
 
diff --git a/libraries/easy/include/userver/easy.hpp b/libraries/easy/include/userver/easy.hpp
index 573858d46e8d..acbecd1ba0db 100644
--- a/libraries/easy/include/userver/easy.hpp
+++ b/libraries/easy/include/userver/easy.hpp
@@ -55,6 +55,8 @@ class HttpBase {
     void AppendComponent() {
         component_list_.Append<Component>();
     }
+    
+    void Schema(std::string_view schema) { schema_ = schema; }
 private:
     void AddHandleConfig(std::string_view path);
 
@@ -63,6 +65,7 @@ class HttpBase {
     const int argc_;
     const char *const* argv_;
     std::string static_config_;
+    std::string schema_;
     components::ComponentList component_list_;
 };
 
@@ -128,6 +131,11 @@ class HttpWith final {
         impl_.AppendComponent<Component>();
         return *this;
     }
+    
+    HttpWith& Schema(std::string_view schema) {
+        impl_.Schema(schema);
+        return *this;
+    }
 
 private:
     impl::HttpBase impl_;
@@ -140,7 +148,7 @@ HttpWith<Dependency>::Callback::Callback(Function func) {
         func_ = std::move(func);
     } else if constexpr (std::is_invocable_r_v<std::string, Function, const HttpRequest&, impl::ConstDependencyRef<Dependency> >) {
         func_ = [f = std::move(func)](const HttpRequest& req, const DependenciesBase& deps) {
-            return f(req, static_cast<Dependency&>(deps));
+            return f(req, static_cast<const Dependency&>(deps));
         };
     } else {
       static_assert(std::is_invocable_r_v<std::string, Function, const HttpRequest&>);
diff --git a/libraries/easy/samples/0_hello_world/main.cpp b/libraries/easy/samples/0_hello_world/main.cpp
index 807bc59222ed..63e2354b759b 100644
--- a/libraries/easy/samples/0_hello_world/main.cpp
+++ b/libraries/easy/samples/0_hello_world/main.cpp
@@ -3,8 +3,16 @@
 
 #include <userver/easy.hpp>
 
+constexpr std::string_view kSchema = R"~(
+CREATE TABLE IF NOT EXISTS key_value_table (
+	key VARCHAR PRIMARY KEY,
+	value VARCHAR
+)
+)~";
+
 int main(int argc, char* argv[]) {
     easy::HttpWith<easy::PgDep>(argc, argv) //
+      .Schema(kSchema)
       .DefaultContentType(http::content_type::kTextPlain)
       .Route("/hello", [](const easy::HttpRequest& /*req*/) {
         return "Hello world";
@@ -14,5 +22,15 @@ int main(int argc, char* argv[]) {
       })
       .Route("/hi", [](const easy::HttpRequest& req) {
         return "Hi, " + req.GetArg("name");
+      })
+      .Route("/kv", [](const easy::HttpRequest& req, const easy::PgDep& dep) {
+        const auto& key = req.GetArg("key");
+        if (req.GetMethod() == server::http::HttpMethod::kGet) {
+            auto res = dep.pg().Execute(storages::postgres::ClusterHostType::kSlave, "SELECT value FROM key_value_table WHERE key=$1", key);
+            return res[0][0].As<std::string>();
+        } else {
+            dep.pg().Execute(storages::postgres::ClusterHostType::kMaster, "INSERT INTO key_value_table VALUES($1, $2) ON CONFLICT DO UPDATE", key, req.GetArg("name"));
+            return {};
+        }
       });
 }
diff --git a/libraries/easy/samples/0_hello_world/tests/conftest.py b/libraries/easy/samples/0_hello_world/tests/conftest.py
index 0c2173fcc3cc..4b1bea98ca3f 100644
--- a/libraries/easy/samples/0_hello_world/tests/conftest.py
+++ b/libraries/easy/samples/0_hello_world/tests/conftest.py
@@ -1,16 +1,18 @@
+# /// [psql prepare]
+import os
 import pytest
+import subprocess
 
 from testsuite.databases.pgsql import discover
 
 pytest_plugins = ['pytest_userver.plugins.postgresql']
 
-@pytest.fixture(scope='session')
-def pgsql_local(service_source_dir, pgsql_local_create):
-    with open(service_source_dir.joinpath('schemas/postgresql/1.sql'), 'w') as f:
-        f.write('CREATE TABLE FOO(int);')
 
-    databases = discover.find_schemas(
-        'admin', [service_source_dir.joinpath('schemas/postgresql')],
-    )
+@pytest.fixture(scope='session')
+def pgsql_local(service_tmpdir, service_binary, pgsql_local_create):
+    schema_path = service_tmpdir.joinpath('schemas')
+    os.mkdir(schema_path)
+    subprocess.run([service_binary, '--dump-schema', schema_path]) 
+    databases = discover.find_schemas('admin', [schema_path])
     return pgsql_local_create(list(databases.values()))
-
+    # /// [psql prepare]
diff --git a/libraries/easy/src/easy.cpp b/libraries/easy/src/easy.cpp
index 75c9bd6a206c..4f6410a001d8 100644
--- a/libraries/easy/src/easy.cpp
+++ b/libraries/easy/src/easy.cpp
@@ -106,10 +106,12 @@ HttpBase::~HttpBase() {
     po::variables_map vm;
     po::options_description desc("Easy options");
     std::string config_dump;
+    std::string schema_dump;
 
     // clang-format off
     desc.add_options()
       ("dump-config", po::value(&config_dump), "path to dump the server config")
+      ("dump-schema", po::value(&schema_dump), "path to dump the DB schema")
     ;
     // clang-format on
 
@@ -120,7 +122,11 @@ HttpBase::~HttpBase() {
         std::ofstream(config_dump) << static_config_;
         return;
     }
-    
+
+    if (vm.count("dump-schema")) {
+        std::ofstream(schema_dump + "/0_pg.sql") << schema_;
+    }
+
     if (argc_ <= 1) {
         components::Run(components::InMemoryConfig{static_config_}, component_list_);
         return;

From 1c8b3ec0a6edd5427dd899359467922f1182894f Mon Sep 17 00:00:00 2001
From: Antony Polukhin <antoshkka@gmail.com>
Date: Sun, 17 Nov 2024 20:47:05 +0300
Subject: [PATCH 10/19] its alive!

---
 libraries/easy/include/userver/easy.hpp          | 10 +++++++---
 libraries/easy/samples/0_hello_world/main.cpp    |  4 ++--
 .../samples/0_hello_world/tests/test_basic.py    | 15 +++++++++++++++
 libraries/easy/src/easy.cpp                      | 16 ++++++++++++----
 4 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/libraries/easy/include/userver/easy.hpp b/libraries/easy/include/userver/easy.hpp
index acbecd1ba0db..6f9cc85b96ae 100644
--- a/libraries/easy/include/userver/easy.hpp
+++ b/libraries/easy/include/userver/easy.hpp
@@ -56,7 +56,7 @@ class HttpBase {
         component_list_.Append<Component>();
     }
     
-    void Schema(std::string_view schema) { schema_ = schema; }
+    void Schema(std::string_view schema);
 private:
     void AddHandleConfig(std::string_view path);
 
@@ -65,7 +65,6 @@ class HttpBase {
     const int argc_;
     const char *const* argv_;
     std::string static_config_;
-    std::string schema_;
     components::ComponentList component_list_;
 };
 
@@ -99,7 +98,12 @@ class HttpWith final {
         impl::UnderlyingCallback func_;
     };
 
-    HttpWith(int argc, const char *const argv[]) : impl_(argc, argv) {}
+    HttpWith(int argc, const char *const argv[]) : impl_(argc, argv) {
+        if constexpr (!std::is_void_v<Dependency>) {
+            impl_.AppendComponent<Dependency>();
+            impl_.AddComponentsConfig(std::string{Dependency::kName} + ": {}");
+        }
+    }
 
     ~HttpWith() {
         DependenciesRegistration(*this);  // ADL is intentional
diff --git a/libraries/easy/samples/0_hello_world/main.cpp b/libraries/easy/samples/0_hello_world/main.cpp
index 63e2354b759b..76786528e91d 100644
--- a/libraries/easy/samples/0_hello_world/main.cpp
+++ b/libraries/easy/samples/0_hello_world/main.cpp
@@ -29,8 +29,8 @@ int main(int argc, char* argv[]) {
             auto res = dep.pg().Execute(storages::postgres::ClusterHostType::kSlave, "SELECT value FROM key_value_table WHERE key=$1", key);
             return res[0][0].As<std::string>();
         } else {
-            dep.pg().Execute(storages::postgres::ClusterHostType::kMaster, "INSERT INTO key_value_table VALUES($1, $2) ON CONFLICT DO UPDATE", key, req.GetArg("name"));
-            return {};
+            dep.pg().Execute(storages::postgres::ClusterHostType::kMaster, "INSERT INTO key_value_table(key, value) VALUES($1, $2) ON CONFLICT (key) DO UPDATE SET value = $2", key, req.GetArg("value"));
+            return std::string{};
         }
       });
 }
diff --git a/libraries/easy/samples/0_hello_world/tests/test_basic.py b/libraries/easy/samples/0_hello_world/tests/test_basic.py
index 696228ccff0c..97d9d1735839 100644
--- a/libraries/easy/samples/0_hello_world/tests/test_basic.py
+++ b/libraries/easy/samples/0_hello_world/tests/test_basic.py
@@ -17,3 +17,18 @@ async def test_hi(service_client):
     assert response.status == 200
     assert 'text/plain' in response.headers['Content-Type']
     assert response.text == 'Hi, pal'
+
+async def test_kv(service_client):
+    response = await service_client.post('/kv?key=1&value=one')
+    assert response.status == 200
+
+    response = await service_client.get('/kv?key=1')
+    assert response.status == 200
+    assert response.text == 'one'
+
+    response = await service_client.post('/kv?key=1&value=again_1')
+    assert response.status == 200
+
+    response = await service_client.get('/kv?key=1')
+    assert response.status == 200
+    assert response.text == 'again_1'
diff --git a/libraries/easy/src/easy.cpp b/libraries/easy/src/easy.cpp
index 4f6410a001d8..922c8f88efc9 100644
--- a/libraries/easy/src/easy.cpp
+++ b/libraries/easy/src/easy.cpp
@@ -49,7 +49,7 @@ constexpr std::string_view kConfigBase = R"~(
 constexpr std::string_view kConfigHandlerTemplate = R"~(
 {0}:
     path: {0}                  # Registering handler by URL '{0}'.
-    method: GET,POST              # It will only reply to GET (HEAD) and POST requests.
+    method: GET,PUT,POST,DELETE,PATCH
     task_processor: main-task-processor  # Run it on CPU bound task processor
 )~";
 
@@ -58,7 +58,8 @@ class EmptyDeps final : public DependenciesBase {
 };
 
 const DependenciesBase& GetDeps(const components::ComponentConfig& config, const components::ComponentContext& context) {
-    const auto* deps = context.FindComponentOptional<DependenciesBase>();
+    const auto* deps = context.
+    FindComponentOptional<DependenciesBase>();
     if (deps) {
         return *deps;
     }
@@ -69,6 +70,7 @@ const DependenciesBase& GetDeps(const components::ComponentConfig& config, const
 
 std::unordered_map<std::string, impl::UnderlyingCallback> g_http_functions_;
 std::optional<http::ContentType> default_content_type_;
+std::string schema_;
 
 }  // anonymous namespace
 
@@ -153,14 +155,20 @@ void HttpBase::AddHandleConfig(std::string_view path) {
 }
 
 void HttpBase::AddComponentsConfig(std::string_view config) {
-    static_config_ += boost::algorithm::replace_all_copy(std::string{config}, "\n", "\n        ");
+    auto conf = fmt::format("\n{}\n", config);
+    static_config_ += boost::algorithm::replace_all_copy(conf, "\n", "\n        ");
 }
 
+void HttpBase::Schema(std::string_view schema) { schema_ = schema; }
+    
 }  // namespace impl
 
 
 PgDep::PgDep(const components::ComponentConfig& config, const components::ComponentContext& context)
-: DependenciesBase{config, context}, pg_cluster_(context.FindComponent<components::Postgres>("postgres").GetCluster()) {}
+: DependenciesBase{config, context}, pg_cluster_(context.FindComponent<components::Postgres>("postgres").GetCluster())
+{
+    pg_cluster_->Execute(storages::postgres::ClusterHostType::kMaster, schema_);
+}
 
 void DependenciesRegistration(HttpWith<PgDep>& app) {
     app.AddComponentsConfig(R"~(

From 3fe07788b03af65574de0f488e080fc49e170e8e Mon Sep 17 00:00:00 2001
From: Antony Polukhin <antoshkka@gmail.com>
Date: Sun, 17 Nov 2024 22:30:27 +0300
Subject: [PATCH 11/19] cleanup

---
 libraries/easy/include/userver/easy.hpp | 41 +++++++++----------------
 libraries/easy/src/easy.cpp             | 18 ++---------
 2 files changed, 17 insertions(+), 42 deletions(-)

diff --git a/libraries/easy/include/userver/easy.hpp b/libraries/easy/include/userver/easy.hpp
index 6f9cc85b96ae..5f67f7946ba8 100644
--- a/libraries/easy/include/userver/easy.hpp
+++ b/libraries/easy/include/userver/easy.hpp
@@ -3,7 +3,6 @@
 #include <functional>
 #include <string>
 #include <string_view>
-#include <unordered_map>
 
 #include <userver/components/component_list.hpp>
 #include <userver/components/component_base.hpp>
@@ -32,11 +31,6 @@ namespace impl {
 
 using UnderlyingCallback = std::function<std::string(const HttpRequest&, const DependenciesBase&)>;
 
-struct AggressiveUnicorn; // Do not unleash
-
-template <class Dependency>
-using ConstDependencyRef = std::conditional_t<std::is_void_v<Dependency>, AggressiveUnicorn, Dependency> const&; 
-
 class HttpBase {
 public:
     HttpBase(int argc, const char *const argv[]);
@@ -70,21 +64,7 @@ class HttpBase {
 
 }
 
-template <class Dependency = void>
-class HttpWith;
-
-inline void DependenciesRegistration(HttpWith<void>&) {}
-
-template <class T>
-inline void DependenciesRegistration(HttpWith<T>&) {
-    static_assert(sizeof(T) && false, "Define `void DependenciesRegistration(HttpWith<T>& app)` "
-        "in the namespace of the your type `T` to automatically add required configurations and "
-        "components to the `app` for your dependences type `T`.  For example:"
-        "void DependenciesRegistration(HttpWith<MyDeps>& app) { app.AppendComponent<MyComponent>(); }"
-    );
-}
-
-template <class Dependency>
+template <class Dependency = DependenciesBase>
 class HttpWith final {
 public:
     class Callback {
@@ -99,10 +79,8 @@ class HttpWith final {
     };
 
     HttpWith(int argc, const char *const argv[]) : impl_(argc, argv) {
-        if constexpr (!std::is_void_v<Dependency>) {
-            impl_.AppendComponent<Dependency>();
-            impl_.AddComponentsConfig(std::string{Dependency::kName} + ": {}");
-        }
+        impl_.AppendComponent<Dependency>();
+        impl_.AddComponentsConfig(std::string{Dependency::kName} + ": {}");
     }
 
     ~HttpWith() {
@@ -145,12 +123,23 @@ class HttpWith final {
     impl::HttpBase impl_;
 };
 
+template <class T>
+inline void DependenciesRegistration(HttpWith<T>&) {
+    static_assert(sizeof(T) && false, "Define `void DependenciesRegistration(HttpWith<T>& app)` "
+        "in the namespace of the your type `T` to automatically add required configurations and "
+        "components to the `app` for your dependences type `T`.  For example:"
+        "void DependenciesRegistration(HttpWith<MyDeps>& app) { app.AppendComponent<MyComponent>(); }"
+    );
+}
+
+inline void DependenciesRegistration(HttpWith<DependenciesBase>&) {}
+
 template <class Dependency>
 template <class Function>
 HttpWith<Dependency>::Callback::Callback(Function func) {
     if constexpr (std::is_invocable_r_v<std::string, Function, const HttpRequest&, const DependenciesBase&>) {
         func_ = std::move(func);
-    } else if constexpr (std::is_invocable_r_v<std::string, Function, const HttpRequest&, impl::ConstDependencyRef<Dependency> >) {
+    } else if constexpr (std::is_invocable_r_v<std::string, Function, const HttpRequest&, const Dependency&>) {
         func_ = [f = std::move(func)](const HttpRequest& req, const DependenciesBase& deps) {
             return f(req, static_cast<const Dependency&>(deps));
         };
diff --git a/libraries/easy/src/easy.cpp b/libraries/easy/src/easy.cpp
index 922c8f88efc9..21c94a7128b4 100644
--- a/libraries/easy/src/easy.cpp
+++ b/libraries/easy/src/easy.cpp
@@ -1,6 +1,7 @@
 #include <userver/easy.hpp>
 
 #include <fstream>
+#include <unordered_map>
 
 #include <boost/program_options.hpp>
 #include <boost/algorithm/string/replace.hpp>
@@ -53,21 +54,6 @@ constexpr std::string_view kConfigHandlerTemplate = R"~(
     task_processor: main-task-processor  # Run it on CPU bound task processor
 )~";
 
-class EmptyDeps final : public DependenciesBase {
-    using DependenciesBase::DependenciesBase;
-};
-
-const DependenciesBase& GetDeps(const components::ComponentConfig& config, const components::ComponentContext& context) {
-    const auto* deps = context.
-    FindComponentOptional<DependenciesBase>();
-    if (deps) {
-        return *deps;
-    }
-
-    static const EmptyDeps empty{config, context};
-    return empty;
-}
-
 std::unordered_map<std::string, impl::UnderlyingCallback> g_http_functions_;
 std::optional<http::ContentType> default_content_type_;
 std::string schema_;
@@ -83,7 +69,7 @@ class HttpBase::Handle final : public server::handlers::HttpHandlerBase {
 public:
     Handle(const components::ComponentConfig& config, const components::ComponentContext& context):
       HttpHandlerBase(config, context),
-      deps_{GetDeps(config, context)},
+      deps_{context.FindComponent<DependenciesBase>()},
       callback_{g_http_functions_[config.Name()]}
     {}
 

From a5dd59137216742fb3a780092eb0aa79485614e0 Mon Sep 17 00:00:00 2001
From: Antony Polukhin <antoshkka@gmail.com>
Date: Tue, 19 Nov 2024 10:36:42 +0300
Subject: [PATCH 12/19] cleanup and samples

---
 libraries/easy/include/userver/easy.hpp       | 140 ++++++++++++------
 libraries/easy/samples/0_hello_world/main.cpp |  34 +----
 .../samples/0_hello_world/tests/conftest.py   |  20 +--
 .../samples/0_hello_world/tests/test_basic.py |  33 +----
 libraries/easy/samples/1_hi/CMakeLists.txt    |   6 +
 libraries/easy/samples/1_hi/main.cpp          |  20 +++
 libraries/easy/samples/1_hi/tests/conftest.py |   4 +
 .../easy/samples/1_hi/tests/test_basic.py     |  12 ++
 .../easy/samples/2_key_value/CMakeLists.txt   |   6 +
 libraries/easy/samples/2_key_value/main.cpp   |  37 +++++
 .../samples/2_key_value/tests/conftest.py     |  18 +++
 .../samples/2_key_value/tests/test_basic.py   |  14 ++
 libraries/easy/samples/CMakeLists.txt         |   6 +
 libraries/easy/src/easy.cpp                   | 113 +++++++-------
 14 files changed, 286 insertions(+), 177 deletions(-)
 create mode 100644 libraries/easy/samples/1_hi/CMakeLists.txt
 create mode 100644 libraries/easy/samples/1_hi/main.cpp
 create mode 100644 libraries/easy/samples/1_hi/tests/conftest.py
 create mode 100644 libraries/easy/samples/1_hi/tests/test_basic.py
 create mode 100644 libraries/easy/samples/2_key_value/CMakeLists.txt
 create mode 100644 libraries/easy/samples/2_key_value/main.cpp
 create mode 100644 libraries/easy/samples/2_key_value/tests/conftest.py
 create mode 100644 libraries/easy/samples/2_key_value/tests/test_basic.py

diff --git a/libraries/easy/include/userver/easy.hpp b/libraries/easy/include/userver/easy.hpp
index 5f67f7946ba8..0220f96e267d 100644
--- a/libraries/easy/include/userver/easy.hpp
+++ b/libraries/easy/include/userver/easy.hpp
@@ -4,8 +4,8 @@
 #include <string>
 #include <string_view>
 
-#include <userver/components/component_list.hpp>
 #include <userver/components/component_base.hpp>
+#include <userver/components/component_list.hpp>
 #include <userver/http/content_type.hpp>
 #include <userver/server/http/http_request.hpp>
 #include <userver/server/request/request_context.hpp>
@@ -17,27 +17,22 @@ USERVER_NAMESPACE_BEGIN
 /// @brief Top namespace for `easy` library
 namespace easy {
 
-using HttpRequest = server::http::HttpRequest;
-using RequestContext = server::request::RequestContext;
-
-class DependenciesBase: public components::ComponentBase {
+class DependenciesBase : public components::ComponentBase {
 public:
     static constexpr std::string_view kName = "easy-dependencies";
     using components::ComponentBase::ComponentBase;
     virtual ~DependenciesBase();
 };
 
-namespace impl {
-
-using UnderlyingCallback = std::function<std::string(const HttpRequest&, const DependenciesBase&)>;
+template <class Dependency>
+struct OfDependency final {};
 
-class HttpBase {
+class HttpBase final {
 public:
-    HttpBase(int argc, const char *const argv[]);
-    ~HttpBase();
-    
+    using Callback = std::function<std::string(const server::http::HttpRequest&, const DependenciesBase&)>;
+
     void DefaultContentType(http::ContentType content_type);
-    void Route(std::string_view path, UnderlyingCallback&& func);
+    void Route(std::string_view path, Callback&& func, std::initializer_list<server::http::HttpMethod> methods);
 
     void AddComponentsConfig(std::string_view config);
 
@@ -49,51 +44,88 @@ class HttpBase {
     void AppendComponent() {
         component_list_.Append<Component>();
     }
-    
+
     void Schema(std::string_view schema);
+    void Port(std::uint16_t port);
+    void LogLevel(logging::Level level);
+
 private:
-    void AddHandleConfig(std::string_view path);
+    template <class>
+    friend class HttpWith;
+
+    HttpBase(int argc, const char* const argv[]);
+    ~HttpBase();
 
     class Handle;
 
     const int argc_;
-    const char *const* argv_;
+    const char* const* argv_;
     std::string static_config_;
     components::ComponentList component_list_;
-};
 
-}
+    std::uint16_t port_ = 8080;
+    logging::Level level_ = logging::Level::kDebug;
+};
 
 template <class Dependency = DependenciesBase>
 class HttpWith final {
 public:
-    class Callback {
+    class Callback final {
     public:
         template <class Function>
         Callback(Function func);
 
-        auto Extract() && noexcept { return std::move(func_); }
+        HttpBase::Callback Extract() && noexcept { return std::move(func_); }
 
     private:
-        impl::UnderlyingCallback func_;
+        HttpBase::Callback func_;
     };
 
-    HttpWith(int argc, const char *const argv[]) : impl_(argc, argv) {
-        impl_.AppendComponent<Dependency>();
-        impl_.AddComponentsConfig(std::string{Dependency::kName} + ": {}");
+    HttpWith(int argc, const char* const argv[]) : impl_(argc, argv) { impl_.AppendComponent<Dependency>(); }
+    ~HttpWith() { Registration(OfDependency<Dependency>{}, impl_); /* ADL is intentional */ }
+
+    HttpWith& DefaultContentType(http::ContentType content_type) {
+        return (impl_.DefaultContentType(content_type), *this);
     }
 
-    ~HttpWith() {
-        DependenciesRegistration(*this);  // ADL is intentional
+    HttpWith& Route(
+        std::string_view path,
+        Callback&& func,
+        std::initializer_list<server::http::HttpMethod> methods =
+            {
+                server::http::HttpMethod::kGet,
+                server::http::HttpMethod::kPost,
+                server::http::HttpMethod::kDelete,
+                server::http::HttpMethod::kPut,
+                server::http::HttpMethod::kPatch,
+            }
+    ) {
+        impl_.Route(path, std::move(func).Extract(), methods);
+        return *this;
     }
-    
-    HttpWith& DefaultContentType(http::ContentType content_type) {
-        impl_.DefaultContentType(content_type);
+
+    HttpWith& Get(std::string_view path, Callback&& func) {
+        impl_.Route(path, std::move(func).Extract(), {server::http::HttpMethod::kGet});
         return *this;
     }
 
-    HttpWith& Route(std::string_view path, Callback&& func) {
-        impl_.Route(path, std::move(func).Extract());
+    HttpWith& Post(std::string_view path, Callback&& func) {
+        impl_.Route(path, std::move(func).Extract(), {server::http::HttpMethod::kPost});
+        return *this;
+    }
+
+    HttpWith& Del(std::string_view path, Callback&& func) {
+        impl_.Route(path, std::move(func).Extract(), {server::http::HttpMethod::kDelete});
+        return *this;
+    }
+
+    HttpWith& Put(std::string_view path, Callback&& func) {
+        impl_.Route(path, std::move(func).Extract(), {server::http::HttpMethod::kPut});
+        return *this;
+    }
+
+    HttpWith& Patch(std::string_view path, Callback&& func) {
+        impl_.Route(path, std::move(func).Extract(), {server::http::HttpMethod::kPatch});
         return *this;
     }
 
@@ -113,41 +145,52 @@ class HttpWith final {
         impl_.AppendComponent<Component>();
         return *this;
     }
-    
+
     HttpWith& Schema(std::string_view schema) {
         impl_.Schema(schema);
         return *this;
     }
 
+    HttpWith& Port(std::uint16_t port) {
+        impl_.Port(port);
+        return *this;
+    }
+
+    HttpWith& LogLevel(logging::Level level) {
+        impl_.LogLevel(level);
+        return *this;
+    }
+
 private:
-    impl::HttpBase impl_;
+    HttpBase impl_;
 };
 
-template <class T>
-inline void DependenciesRegistration(HttpWith<T>&) {
-    static_assert(sizeof(T) && false, "Define `void DependenciesRegistration(HttpWith<T>& app)` "
-        "in the namespace of the your type `T` to automatically add required configurations and "
-        "components to the `app` for your dependences type `T`.  For example:"
-        "void DependenciesRegistration(HttpWith<MyDeps>& app) { app.AppendComponent<MyComponent>(); }"
+template <class T, class HttpBase>
+inline void Registration(T, HttpBase&&) {
+    static_assert(
+        sizeof(T) && false,
+        "Define `void Registration(easy::OfDependency<T>, HttpBase& app)` "
+        "in the namespace of the your dependency type `T` to automatically add required configurations and "
+        "components to the `app`.  For example:"
+        "void Registration(easy::OfDependency<MyDeps>, easy::HttpBase& app) { app.AppendComponent<MyComponent>(); }"
     );
 }
 
-inline void DependenciesRegistration(HttpWith<DependenciesBase>&) {}
+inline void Registration(OfDependency<DependenciesBase>, HttpBase&) {}
 
 template <class Dependency>
 template <class Function>
 HttpWith<Dependency>::Callback::Callback(Function func) {
-    if constexpr (std::is_invocable_r_v<std::string, Function, const HttpRequest&, const DependenciesBase&>) {
-        func_ = std::move(func);
-    } else if constexpr (std::is_invocable_r_v<std::string, Function, const HttpRequest&, const Dependency&>) {
+    using server::http::HttpRequest;
+    if constexpr (std::is_invocable_r_v<std::string, Function, const HttpRequest&, const Dependency&>) {
         func_ = [f = std::move(func)](const HttpRequest& req, const DependenciesBase& deps) {
             return f(req, static_cast<const Dependency&>(deps));
         };
+    } else if constexpr (std::is_invocable_r_v<std::string, Function, const HttpRequest&, const DependenciesBase&>) {
+        func_ = std::move(func);
     } else {
-      static_assert(std::is_invocable_r_v<std::string, Function, const HttpRequest&>);
-      func_ = [f = std::move(func)](const HttpRequest& req, const DependenciesBase&) {
-        return f(req);
-      };
+        static_assert(std::is_invocable_r_v<std::string, Function, const HttpRequest&>);
+        func_ = [f = std::move(func)](const HttpRequest& req, const DependenciesBase&) { return f(req); };
     }
 }
 
@@ -161,8 +204,7 @@ class PgDep : public DependenciesBase {
     storages::postgres::ClusterPtr pg_cluster_;
 };
 
-void DependenciesRegistration(HttpWith<PgDep>& app);
-
+void Registration(OfDependency<PgDep>, HttpBase& app);
 
 }  // namespace easy
 
diff --git a/libraries/easy/samples/0_hello_world/main.cpp b/libraries/easy/samples/0_hello_world/main.cpp
index 76786528e91d..c50340d8a070 100644
--- a/libraries/easy/samples/0_hello_world/main.cpp
+++ b/libraries/easy/samples/0_hello_world/main.cpp
@@ -3,34 +3,10 @@
 
 #include <userver/easy.hpp>
 
-constexpr std::string_view kSchema = R"~(
-CREATE TABLE IF NOT EXISTS key_value_table (
-	key VARCHAR PRIMARY KEY,
-	value VARCHAR
-)
-)~";
-
 int main(int argc, char* argv[]) {
-    easy::HttpWith<easy::PgDep>(argc, argv) //
-      .Schema(kSchema)
-      .DefaultContentType(http::content_type::kTextPlain)
-      .Route("/hello", [](const easy::HttpRequest& /*req*/) {
-        return "Hello world";
-      })
-      .Route("/hello/to/{user}", [](const easy::HttpRequest& req) {
-        return "Hello, " + req.GetPathArg("user");
-      })
-      .Route("/hi", [](const easy::HttpRequest& req) {
-        return "Hi, " + req.GetArg("name");
-      })
-      .Route("/kv", [](const easy::HttpRequest& req, const easy::PgDep& dep) {
-        const auto& key = req.GetArg("key");
-        if (req.GetMethod() == server::http::HttpMethod::kGet) {
-            auto res = dep.pg().Execute(storages::postgres::ClusterHostType::kSlave, "SELECT value FROM key_value_table WHERE key=$1", key);
-            return res[0][0].As<std::string>();
-        } else {
-            dep.pg().Execute(storages::postgres::ClusterHostType::kMaster, "INSERT INTO key_value_table(key, value) VALUES($1, $2) ON CONFLICT (key) DO UPDATE SET value = $2", key, req.GetArg("value"));
-            return std::string{};
-        }
-      });
+    easy::HttpWith(argc, argv)
+        .DefaultContentType(http::content_type::kTextPlain)
+        .Route("/hello", [](const server::http::HttpRequest& /*req*/) {
+            return "Hello world";  // Just return the string as a response body
+        });
 }
diff --git a/libraries/easy/samples/0_hello_world/tests/conftest.py b/libraries/easy/samples/0_hello_world/tests/conftest.py
index 4b1bea98ca3f..87356961ffd6 100644
--- a/libraries/easy/samples/0_hello_world/tests/conftest.py
+++ b/libraries/easy/samples/0_hello_world/tests/conftest.py
@@ -1,18 +1,4 @@
 # /// [psql prepare]
-import os
-import pytest
-import subprocess
-
-from testsuite.databases.pgsql import discover
-
-pytest_plugins = ['pytest_userver.plugins.postgresql']
-
-
-@pytest.fixture(scope='session')
-def pgsql_local(service_tmpdir, service_binary, pgsql_local_create):
-    schema_path = service_tmpdir.joinpath('schemas')
-    os.mkdir(schema_path)
-    subprocess.run([service_binary, '--dump-schema', schema_path]) 
-    databases = discover.find_schemas('admin', [schema_path])
-    return pgsql_local_create(list(databases.values()))
-    # /// [psql prepare]
+# Use only core plugin
+pytest_plugins = ["pytest_userver.plugins.core"]
+# /// [psql prepare]
diff --git a/libraries/easy/samples/0_hello_world/tests/test_basic.py b/libraries/easy/samples/0_hello_world/tests/test_basic.py
index 97d9d1735839..c7490424d6c7 100644
--- a/libraries/easy/samples/0_hello_world/tests/test_basic.py
+++ b/libraries/easy/samples/0_hello_world/tests/test_basic.py
@@ -1,34 +1,7 @@
 # /// [Functional test]
 async def test_hello_simple(service_client):
-    response = await service_client.get('/hello')
+    response = await service_client.get("/hello")
     assert response.status == 200
-    assert 'text/plain' in response.headers['Content-Type']
-    assert response.text == 'Hello world'
+    assert "text/plain" in response.headers["Content-Type"]
+    assert response.text == "Hello world"
     # /// [Functional test]
-
-async def test_hello_to(service_client):
-    response = await service_client.get('/hello/to/flusk')
-    assert response.status == 200
-    assert 'text/plain' in response.headers['Content-Type']
-    assert response.text == 'Hello, flusk'
-
-async def test_hi(service_client):
-    response = await service_client.get('/hi?name=pal')
-    assert response.status == 200
-    assert 'text/plain' in response.headers['Content-Type']
-    assert response.text == 'Hi, pal'
-
-async def test_kv(service_client):
-    response = await service_client.post('/kv?key=1&value=one')
-    assert response.status == 200
-
-    response = await service_client.get('/kv?key=1')
-    assert response.status == 200
-    assert response.text == 'one'
-
-    response = await service_client.post('/kv?key=1&value=again_1')
-    assert response.status == 200
-
-    response = await service_client.get('/kv?key=1')
-    assert response.status == 200
-    assert response.text == 'again_1'
diff --git a/libraries/easy/samples/1_hi/CMakeLists.txt b/libraries/easy/samples/1_hi/CMakeLists.txt
new file mode 100644
index 000000000000..0dba282c82e0
--- /dev/null
+++ b/libraries/easy/samples/1_hi/CMakeLists.txt
@@ -0,0 +1,6 @@
+project(userver-easy-samples-hi CXX)
+
+add_executable(${PROJECT_NAME} "main.cpp")
+target_link_libraries(${PROJECT_NAME} userver::easy)
+
+userver_testsuite_add_simple(DUMP_CONFIG True)
diff --git a/libraries/easy/samples/1_hi/main.cpp b/libraries/easy/samples/1_hi/main.cpp
new file mode 100644
index 000000000000..3afd0fce47fc
--- /dev/null
+++ b/libraries/easy/samples/1_hi/main.cpp
@@ -0,0 +1,20 @@
+// Note: this is for the purposes of samples only
+#include <userver/utest/using_namespace_userver.hpp>
+
+#include <userver/easy.hpp>
+
+std::string Greet(const server::http::HttpRequest& req) {
+    const auto& username = req.GetPathArg("user");
+    return "Hello, " + username;
+}
+
+struct Hi {
+    std::string operator()(const server::http::HttpRequest& req) const { return "Hi, " + req.GetArg("name"); }
+};
+
+int main(int argc, char* argv[]) {
+    easy::HttpWith(argc, argv)
+        .DefaultContentType(http::content_type::kTextPlain)
+        .Get("/hi/{user}", &Greet)
+        .Get("/hi", Hi{});
+}
diff --git a/libraries/easy/samples/1_hi/tests/conftest.py b/libraries/easy/samples/1_hi/tests/conftest.py
new file mode 100644
index 000000000000..87356961ffd6
--- /dev/null
+++ b/libraries/easy/samples/1_hi/tests/conftest.py
@@ -0,0 +1,4 @@
+# /// [psql prepare]
+# Use only core plugin
+pytest_plugins = ["pytest_userver.plugins.core"]
+# /// [psql prepare]
diff --git a/libraries/easy/samples/1_hi/tests/test_basic.py b/libraries/easy/samples/1_hi/tests/test_basic.py
new file mode 100644
index 000000000000..77e14f506f5f
--- /dev/null
+++ b/libraries/easy/samples/1_hi/tests/test_basic.py
@@ -0,0 +1,12 @@
+async def test_hi_to(service_client):
+    response = await service_client.get("/hi/flusk")
+    assert response.status == 200
+    assert "text/plain" in response.headers["Content-Type"]
+    assert response.text == "Hello, flusk"
+
+
+async def test_hi(service_client):
+    response = await service_client.get("/hi?name=pal")
+    assert response.status == 200
+    assert "text/plain" in response.headers["Content-Type"]
+    assert response.text == "Hi, pal"
diff --git a/libraries/easy/samples/2_key_value/CMakeLists.txt b/libraries/easy/samples/2_key_value/CMakeLists.txt
new file mode 100644
index 000000000000..279540941ea8
--- /dev/null
+++ b/libraries/easy/samples/2_key_value/CMakeLists.txt
@@ -0,0 +1,6 @@
+project(userver-easy-samples-key-value CXX)
+
+add_executable(${PROJECT_NAME} "main.cpp")
+target_link_libraries(${PROJECT_NAME} userver::easy)
+
+userver_testsuite_add_simple(DUMP_CONFIG True)
diff --git a/libraries/easy/samples/2_key_value/main.cpp b/libraries/easy/samples/2_key_value/main.cpp
new file mode 100644
index 000000000000..cf8967422e8a
--- /dev/null
+++ b/libraries/easy/samples/2_key_value/main.cpp
@@ -0,0 +1,37 @@
+// Note: this is for the purposes of samples only
+#include <userver/utest/using_namespace_userver.hpp>
+
+#include <userver/easy.hpp>
+
+constexpr std::string_view kSchema = R"~(
+CREATE TABLE IF NOT EXISTS key_value_table (
+	key VARCHAR PRIMARY KEY,
+	value VARCHAR
+)
+)~";
+
+int main(int argc, char* argv[]) {
+    easy::HttpWith<easy::PgDep>(argc, argv)
+        .Schema(kSchema)
+        .DefaultContentType(http::content_type::kTextPlain)
+        .Get(
+            "/kv",
+            [](const server::http::HttpRequest& req, const easy::PgDep& dep) {
+                auto res = dep.pg().Execute(
+                    storages::postgres::ClusterHostType::kSlave,
+                    "SELECT value FROM key_value_table WHERE key=$1",
+                    req.GetArg("key")
+                );
+                return res[0][0].As<std::string>();
+            }
+        )
+        .Post("/kv", [](const server::http::HttpRequest& req, const auto& dep) {
+            dep.pg().Execute(
+                storages::postgres::ClusterHostType::kMaster,
+                "INSERT INTO key_value_table(key, value) VALUES($1, $2) ON CONFLICT (key) DO UPDATE SET value = $2",
+                req.GetArg("key"),
+                req.GetArg("value")
+            );
+            return std::string{};
+        });
+}
diff --git a/libraries/easy/samples/2_key_value/tests/conftest.py b/libraries/easy/samples/2_key_value/tests/conftest.py
new file mode 100644
index 000000000000..2a91ee35c675
--- /dev/null
+++ b/libraries/easy/samples/2_key_value/tests/conftest.py
@@ -0,0 +1,18 @@
+# /// [psql prepare]
+import os
+import pytest
+import subprocess
+
+from testsuite.databases.pgsql import discover
+
+pytest_plugins = ["pytest_userver.plugins.postgresql"]
+
+
+@pytest.fixture(scope="session")
+def pgsql_local(service_tmpdir, service_binary, pgsql_local_create):
+    schema_path = service_tmpdir.joinpath("schemas")
+    os.mkdir(schema_path)
+    subprocess.run([service_binary, "--dump-schema", schema_path])
+    databases = discover.find_schemas("admin", [schema_path])
+    return pgsql_local_create(list(databases.values()))
+    # /// [psql prepare]
diff --git a/libraries/easy/samples/2_key_value/tests/test_basic.py b/libraries/easy/samples/2_key_value/tests/test_basic.py
new file mode 100644
index 000000000000..b79fcc3a2009
--- /dev/null
+++ b/libraries/easy/samples/2_key_value/tests/test_basic.py
@@ -0,0 +1,14 @@
+async def test_kv(service_client):
+    response = await service_client.post("/kv?key=1&value=one")
+    assert response.status == 200
+
+    response = await service_client.get("/kv?key=1")
+    assert response.status == 200
+    assert response.text == "one"
+
+    response = await service_client.post("/kv?key=1&value=again_1")
+    assert response.status == 200
+
+    response = await service_client.get("/kv?key=1")
+    assert response.status == 200
+    assert response.text == "again_1"
diff --git a/libraries/easy/samples/CMakeLists.txt b/libraries/easy/samples/CMakeLists.txt
index a2b65677dfa7..5cc4652808bc 100644
--- a/libraries/easy/samples/CMakeLists.txt
+++ b/libraries/easy/samples/CMakeLists.txt
@@ -4,3 +4,9 @@ add_custom_target(${PROJECT_NAME})
 
 add_subdirectory(0_hello_world)
 add_dependencies(${PROJECT_NAME} ${PROJECT_NAME}-hello-world)
+
+add_subdirectory(1_hi)
+add_dependencies(${PROJECT_NAME} ${PROJECT_NAME}-hi)
+
+add_subdirectory(2_key_value)
+add_dependencies(${PROJECT_NAME} ${PROJECT_NAME}-key-value)
diff --git a/libraries/easy/src/easy.cpp b/libraries/easy/src/easy.cpp
index 21c94a7128b4..e6e749d9f9cb 100644
--- a/libraries/easy/src/easy.cpp
+++ b/libraries/easy/src/easy.cpp
@@ -3,17 +3,17 @@
 #include <fstream>
 #include <unordered_map>
 
-#include <boost/program_options.hpp>
 #include <boost/algorithm/string/replace.hpp>
+#include <boost/program_options.hpp>
 
+#include <userver/clients/dns/component.hpp>
+#include <userver/components/component_context.hpp>
 #include <userver/components/minimal_server_component_list.hpp>
 #include <userver/components/run.hpp>
-#include <userver/components/component_context.hpp>
 #include <userver/server/handlers/http_handler_base.hpp>
+#include <userver/storages/postgres/component.hpp>
 #include <userver/testsuite/testsuite_support.hpp>
-#include <userver/clients/dns/component.hpp>
 #include <userver/utils/daemon_run.hpp>
-#include <userver/storages/postgres/component.hpp>
 
 USERVER_NAMESPACE_BEGIN
 
@@ -33,62 +33,74 @@ constexpr std::string_view kConfigBase = R"~(
     default_task_processor: main-task-processor  # Task processor in which components start.
 
     components:                       # Configuring components that were registered via component_list
-        server:
-            listener:                 # configuring the main listening socket...
-                port: 8080            # ...to listen on this port and...
-                task_processor: main-task-processor    # ...process incoming requests on this task processor.
-        logging:
-            fs-task-processor: fs-task-processor
-            loggers:
-                default:
-                    file_path: '@stderr'
-                    level: debug
-                    overflow_behavior: discard  # Drop logs if the system is too busy to write them down.
 )~";
 
+constexpr std::string_view kConfigServerTemplate = R"~(
+server:
+    listener:                 # configuring the main listening socket...
+        port: {}            # ...to listen on this port and...
+        task_processor: main-task-processor    # ...process incoming requests on this task processor.
+)~";
+
+constexpr std::string_view kConfigLoggingTemplate = R"~(
+logging:
+    fs-task-processor: fs-task-processor
+    loggers:
+        default:
+            file_path: '@stderr'
+            level: {}
+            overflow_behavior: discard  # Drop logs if the system is too busy to write them down.
+)~";
 
 constexpr std::string_view kConfigHandlerTemplate = R"~(
 {0}:
-    path: {0}                  # Registering handler by URL '{0}'.
-    method: GET,PUT,POST,DELETE,PATCH
+    path: {1}                  # Registering handler by URL '{1}'.
+    method: {2}
     task_processor: main-task-processor  # Run it on CPU bound task processor
 )~";
 
-std::unordered_map<std::string, impl::UnderlyingCallback> g_http_functions_;
-std::optional<http::ContentType> default_content_type_;
-std::string schema_;
+struct SharedPyaload {
+  std::unordered_map<std::string, HttpBase::Callback> http_functions;
+  std::optional<http::ContentType> default_content_type;
+  std::string schema;
+};
 
-}  // anonymous namespace
+SharedPyaload globals{};
 
+}  // anonymous namespace
 
 DependenciesBase::~DependenciesBase() = default;
 
-namespace impl {
-
 class HttpBase::Handle final : public server::handlers::HttpHandlerBase {
 public:
-    Handle(const components::ComponentConfig& config, const components::ComponentContext& context):
-      HttpHandlerBase(config, context),
-      deps_{context.FindComponent<DependenciesBase>()},
-      callback_{g_http_functions_[config.Name()]}
-    {}
-
-    std::string HandleRequestThrow(const HttpRequest& request, RequestContext&) const override {
-        if (default_content_type_) {
-            request.GetHttpResponse().SetContentType(*default_content_type_);
+    Handle(const components::ComponentConfig& config, const components::ComponentContext& context)
+        : HttpHandlerBase(config, context),
+          deps_{context.FindComponent<DependenciesBase>()},
+          callback_{globals.http_functions.at(config.Name())} {}
+
+    std::string HandleRequestThrow(const server::http::HttpRequest& request, server::request::RequestContext&)
+        const override {
+        if (globals.default_content_type) {
+            request.GetHttpResponse().SetContentType(*globals.default_content_type);
         }
         return callback_(request, deps_);
     }
 
 private:
     const DependenciesBase& deps_;
-    impl::UnderlyingCallback& callback_;
+    HttpBase::Callback& callback_;
 };
 
-HttpBase::HttpBase(int argc, const char *const argv[]) : argc_{argc}, argv_{argv}, static_config_{kConfigBase},
+HttpBase::HttpBase(int argc, const char* const argv[])
+    : argc_{argc},
+      argv_{argv},
+      static_config_{kConfigBase},
       component_list_{components::MinimalServerComponentList()} {}
 
 HttpBase::~HttpBase() {
+    AddComponentsConfig(fmt::format(kConfigServerTemplate, port_));
+    AddComponentsConfig(fmt::format(kConfigLoggingTemplate, ToString(level_)));
+
     namespace po = boost::program_options;
 
     po::variables_map vm;
@@ -112,7 +124,7 @@ HttpBase::~HttpBase() {
     }
 
     if (vm.count("dump-schema")) {
-        std::ofstream(schema_dump + "/0_pg.sql") << schema_;
+        std::ofstream(schema_dump + "/0_pg.sql") << globals.schema;
     }
 
     if (argc_ <= 1) {
@@ -126,18 +138,14 @@ HttpBase::~HttpBase() {
     }
 }
 
-void HttpBase::DefaultContentType(http::ContentType content_type) {
-    default_content_type_ = content_type;
-}
+void HttpBase::DefaultContentType(http::ContentType content_type) { globals.default_content_type = content_type; }
 
-void HttpBase::Route(std::string_view path, UnderlyingCallback&& func) {
-    g_http_functions_.emplace(path, std::move(func));
-    component_list_.Append<Handle>(path);
-    AddHandleConfig(path);
-}
+void HttpBase::Route(std::string_view path, Callback&& func, std::initializer_list<server::http::HttpMethod> methods) {
+    auto component_name = fmt::format("{}-{}", path, fmt::join(methods, ","));
 
-void HttpBase::AddHandleConfig(std::string_view path) {
-    AddComponentsConfig(fmt::format(kConfigHandlerTemplate, path));
+    globals.http_functions.emplace(component_name, std::move(func));
+    component_list_.Append<Handle>(component_name);
+    AddComponentsConfig(fmt::format(kConfigHandlerTemplate, component_name, path, fmt::join(methods, ",")));
 }
 
 void HttpBase::AddComponentsConfig(std::string_view config) {
@@ -145,18 +153,19 @@ void HttpBase::AddComponentsConfig(std::string_view config) {
     static_config_ += boost::algorithm::replace_all_copy(conf, "\n", "\n        ");
 }
 
-void HttpBase::Schema(std::string_view schema) { schema_ = schema; }
-    
-}  // namespace impl
+void HttpBase::Schema(std::string_view schema) { globals.schema = schema; }
+
+void HttpBase::Port(std::uint16_t port) { port_ = port; }
 
+void HttpBase::LogLevel(logging::Level level) { level_ = level; }
 
 PgDep::PgDep(const components::ComponentConfig& config, const components::ComponentContext& context)
-: DependenciesBase{config, context}, pg_cluster_(context.FindComponent<components::Postgres>("postgres").GetCluster())
-{
-    pg_cluster_->Execute(storages::postgres::ClusterHostType::kMaster, schema_);
+    : DependenciesBase{config, context},
+      pg_cluster_(context.FindComponent<components::Postgres>("postgres").GetCluster()) {
+    pg_cluster_->Execute(storages::postgres::ClusterHostType::kMaster, globals.schema);
 }
 
-void DependenciesRegistration(HttpWith<PgDep>& app) {
+void Registration(OfDependency<PgDep>, HttpBase& app) {
     app.AddComponentsConfig(R"~(
 postgres:
     dbconnection#env: POSTGRESQL

From e65f6e5df1dd5b08303a11dd082e3ae1257b0d04 Mon Sep 17 00:00:00 2001
From: Antony Polukhin <antoshkka@gmail.com>
Date: Tue, 19 Nov 2024 10:58:42 +0300
Subject: [PATCH 13/19] update

---
 libraries/easy/CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/easy/CMakeLists.txt b/libraries/easy/CMakeLists.txt
index 67e1813b1990..2a1b45623a5e 100644
--- a/libraries/easy/CMakeLists.txt
+++ b/libraries/easy/CMakeLists.txt
@@ -6,6 +6,6 @@ userver_module(easy
     UTEST_SOURCES "${CMAKE_CURRENT_SOURCE_DIR}/src/*_test.cpp"
 )
 
-if(USERVER_IS_THE_ROOT_PROJECT)
+if(USERVER_BUILD_SAMPLES)
   add_subdirectory(samples)
 endif()

From 34e570e621c77f592166101573addc846bef7a0f Mon Sep 17 00:00:00 2001
From: Antony Polukhin <antoshkka@gmail.com>
Date: Tue, 19 Nov 2024 11:14:13 +0300
Subject: [PATCH 14/19] tweaks

---
 libraries/easy/include/userver/easy.hpp | 2 ++
 libraries/easy/src/easy.cpp             | 4 +++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/libraries/easy/include/userver/easy.hpp b/libraries/easy/include/userver/easy.hpp
index 0220f96e267d..3d6e52d5c379 100644
--- a/libraries/easy/include/userver/easy.hpp
+++ b/libraries/easy/include/userver/easy.hpp
@@ -22,6 +22,8 @@ class DependenciesBase : public components::ComponentBase {
     static constexpr std::string_view kName = "easy-dependencies";
     using components::ComponentBase::ComponentBase;
     virtual ~DependenciesBase();
+
+    static const std::string& GetSchema() noexcept;
 };
 
 template <class Dependency>
diff --git a/libraries/easy/src/easy.cpp b/libraries/easy/src/easy.cpp
index e6e749d9f9cb..dde9a301320b 100644
--- a/libraries/easy/src/easy.cpp
+++ b/libraries/easy/src/easy.cpp
@@ -71,6 +71,8 @@ SharedPyaload globals{};
 
 DependenciesBase::~DependenciesBase() = default;
 
+const std::string& DependenciesBase::GetSchema() noexcept { return globals.schema; }
+
 class HttpBase::Handle final : public server::handlers::HttpHandlerBase {
 public:
     Handle(const components::ComponentConfig& config, const components::ComponentContext& context)
@@ -162,7 +164,7 @@ void HttpBase::LogLevel(logging::Level level) { level_ = level; }
 PgDep::PgDep(const components::ComponentConfig& config, const components::ComponentContext& context)
     : DependenciesBase{config, context},
       pg_cluster_(context.FindComponent<components::Postgres>("postgres").GetCluster()) {
-    pg_cluster_->Execute(storages::postgres::ClusterHostType::kMaster, globals.schema);
+    pg_cluster_->Execute(storages::postgres::ClusterHostType::kMaster, GetSchema());
 }
 
 void Registration(OfDependency<PgDep>, HttpBase& app) {

From b910a2f6300c336ea3ab9ddc58357f3dead20bf7 Mon Sep 17 00:00:00 2001
From: Antony Polukhin <antoshkka@gmail.com>
Date: Fri, 22 Nov 2024 10:34:58 +0300
Subject: [PATCH 15/19] more samples

---
 .../3_custom_dependency/CMakeLists.txt        |  6 ++
 .../easy/samples/3_custom_dependency/main.cpp | 64 +++++++++++++++++++
 .../3_custom_dependency/tests/conftest.py     | 18 ++++++
 .../3_custom_dependency/tests/test_basic.py   | 10 +++
 libraries/easy/samples/CMakeLists.txt         |  3 +
 libraries/easy/src/easy.cpp                   |  6 +-
 6 files changed, 104 insertions(+), 3 deletions(-)
 create mode 100644 libraries/easy/samples/3_custom_dependency/CMakeLists.txt
 create mode 100644 libraries/easy/samples/3_custom_dependency/main.cpp
 create mode 100644 libraries/easy/samples/3_custom_dependency/tests/conftest.py
 create mode 100644 libraries/easy/samples/3_custom_dependency/tests/test_basic.py

diff --git a/libraries/easy/samples/3_custom_dependency/CMakeLists.txt b/libraries/easy/samples/3_custom_dependency/CMakeLists.txt
new file mode 100644
index 000000000000..d7b47e6bf129
--- /dev/null
+++ b/libraries/easy/samples/3_custom_dependency/CMakeLists.txt
@@ -0,0 +1,6 @@
+project(userver-easy-samples-custom-dependency CXX)
+
+add_executable(${PROJECT_NAME} "main.cpp")
+target_link_libraries(${PROJECT_NAME} userver::easy)
+
+userver_testsuite_add_simple(DUMP_CONFIG True)
diff --git a/libraries/easy/samples/3_custom_dependency/main.cpp b/libraries/easy/samples/3_custom_dependency/main.cpp
new file mode 100644
index 000000000000..bd719fe5be4d
--- /dev/null
+++ b/libraries/easy/samples/3_custom_dependency/main.cpp
@@ -0,0 +1,64 @@
+// Note: this is for the purposes of samples only
+#include <userver/utest/using_namespace_userver.hpp>
+
+#include <userver/easy.hpp>
+#include <userver/yaml_config/merge_schemas.hpp>
+
+constexpr std::string_view kSchema = R"~(
+CREATE TABLE IF NOT EXISTS events_table (
+  id serial NOT NULL,
+	action VARCHAR PRIMARY KEY,
+	host_id INTEGER
+)
+)~";
+
+class MyDependency : public easy::PgDep {
+public:
+    MyDependency(const components::ComponentConfig& config, const components::ComponentContext& context)
+        : PgDep(config, context), host_id_(config["host_id"].As<int>()) {}
+
+    int host_id() const { return host_id_; }
+
+    static yaml_config::Schema GetStaticConfigSchema() {
+        return yaml_config::MergeSchemas<easy::PgDep>(R"(
+    type: object
+    description: ID of the host
+    additionalProperties: false
+    properties:
+        host_id:
+            type: integer
+            description: ID of the host
+    )");
+    }
+
+private:
+    const int host_id_;
+};
+
+void Registration(easy::OfDependency<MyDependency>, easy::HttpBase& app) {
+    Registration(easy::OfDependency<easy::PgDep>{}, app);  // base class initilization
+
+    app.AddComponentsConfig(R"~(
+easy-dependencies:
+    host_id#env: HOST_ID
+    host_id#fallback: 42
+)~");
+}
+
+template <>
+inline constexpr auto components::kConfigFileMode<MyDependency> = ConfigFileMode::kNotRequired;
+
+int main(int argc, char* argv[]) {
+    easy::HttpWith<MyDependency>(argc, argv)
+        .Schema(kSchema)
+        .DefaultContentType(http::content_type::kTextPlain)
+        .Post("/log", [](const server::http::HttpRequest& req, const MyDependency& dep) {
+            dep.pg().Execute(
+                storages::postgres::ClusterHostType::kMaster,
+                "INSERT INTO events_table(action, host_id) VALUES($1, $2)",
+                req.GetArg("action"),
+                dep.host_id()
+            );
+            return std::string{};
+        });
+}
diff --git a/libraries/easy/samples/3_custom_dependency/tests/conftest.py b/libraries/easy/samples/3_custom_dependency/tests/conftest.py
new file mode 100644
index 000000000000..2a91ee35c675
--- /dev/null
+++ b/libraries/easy/samples/3_custom_dependency/tests/conftest.py
@@ -0,0 +1,18 @@
+# /// [psql prepare]
+import os
+import pytest
+import subprocess
+
+from testsuite.databases.pgsql import discover
+
+pytest_plugins = ["pytest_userver.plugins.postgresql"]
+
+
+@pytest.fixture(scope="session")
+def pgsql_local(service_tmpdir, service_binary, pgsql_local_create):
+    schema_path = service_tmpdir.joinpath("schemas")
+    os.mkdir(schema_path)
+    subprocess.run([service_binary, "--dump-schema", schema_path])
+    databases = discover.find_schemas("admin", [schema_path])
+    return pgsql_local_create(list(databases.values()))
+    # /// [psql prepare]
diff --git a/libraries/easy/samples/3_custom_dependency/tests/test_basic.py b/libraries/easy/samples/3_custom_dependency/tests/test_basic.py
new file mode 100644
index 000000000000..25735a7b0f67
--- /dev/null
+++ b/libraries/easy/samples/3_custom_dependency/tests/test_basic.py
@@ -0,0 +1,10 @@
+async def test_log_action(service_client, pgsql):
+    response = await service_client.post("/log?action=test_1")
+    assert response.status == 200
+
+    cursor = pgsql["0_pg"].cursor()  # '0_pg.sql' is created by easy::PgDep, so the database is '0_pg'
+    cursor.execute("SELECT action, host_id FROM events_table WHERE id=1")
+    result = cursor.fetchall()
+    assert len(result) == 1
+    assert result[0][0] == "test_1"
+    assert result[0][1] == 42
diff --git a/libraries/easy/samples/CMakeLists.txt b/libraries/easy/samples/CMakeLists.txt
index 5cc4652808bc..ee07b23e857a 100644
--- a/libraries/easy/samples/CMakeLists.txt
+++ b/libraries/easy/samples/CMakeLists.txt
@@ -10,3 +10,6 @@ add_dependencies(${PROJECT_NAME} ${PROJECT_NAME}-hi)
 
 add_subdirectory(2_key_value)
 add_dependencies(${PROJECT_NAME} ${PROJECT_NAME}-key-value)
+
+add_subdirectory(3_custom_dependency)
+add_dependencies(${PROJECT_NAME} ${PROJECT_NAME}-custom-dependency)
diff --git a/libraries/easy/src/easy.cpp b/libraries/easy/src/easy.cpp
index dde9a301320b..d461a8c22479 100644
--- a/libraries/easy/src/easy.cpp
+++ b/libraries/easy/src/easy.cpp
@@ -60,9 +60,9 @@ constexpr std::string_view kConfigHandlerTemplate = R"~(
 )~";
 
 struct SharedPyaload {
-  std::unordered_map<std::string, HttpBase::Callback> http_functions;
-  std::optional<http::ContentType> default_content_type;
-  std::string schema;
+    std::unordered_map<std::string, HttpBase::Callback> http_functions;
+    std::optional<http::ContentType> default_content_type;
+    std::string schema;
 };
 
 SharedPyaload globals{};

From de0d755a6ec293f07987d1dd702739cb972191a0 Mon Sep 17 00:00:00 2001
From: Antony Polukhin <antoshkka@gmail.com>
Date: Fri, 29 Nov 2024 10:15:43 +0300
Subject: [PATCH 16/19] JSON example and docs

---
 libraries/easy/include/userver/easy.hpp       | 79 ++++++++++++++++++-
 libraries/easy/samples/3_json/CMakeLists.txt  | 24 ++++++
 libraries/easy/samples/3_json/main.cpp        | 44 +++++++++++
 .../samples/3_json/schemas/key_value.yaml     | 17 ++++
 .../tests/conftest.py                         |  0
 .../easy/samples/3_json/tests/test_basic.py   | 18 +++++
 .../CMakeLists.txt                            |  0
 .../main.cpp                                  |  0
 .../4_custom_dependency/tests/conftest.py     | 18 +++++
 .../tests/test_basic.py                       |  0
 libraries/easy/samples/CMakeLists.txt         |  5 +-
 11 files changed, 201 insertions(+), 4 deletions(-)
 create mode 100644 libraries/easy/samples/3_json/CMakeLists.txt
 create mode 100644 libraries/easy/samples/3_json/main.cpp
 create mode 100644 libraries/easy/samples/3_json/schemas/key_value.yaml
 rename libraries/easy/samples/{3_custom_dependency => 3_json}/tests/conftest.py (100%)
 create mode 100644 libraries/easy/samples/3_json/tests/test_basic.py
 rename libraries/easy/samples/{3_custom_dependency => 4_custom_dependency}/CMakeLists.txt (100%)
 rename libraries/easy/samples/{3_custom_dependency => 4_custom_dependency}/main.cpp (100%)
 create mode 100644 libraries/easy/samples/4_custom_dependency/tests/conftest.py
 rename libraries/easy/samples/{3_custom_dependency => 4_custom_dependency}/tests/test_basic.py (100%)

diff --git a/libraries/easy/include/userver/easy.hpp b/libraries/easy/include/userver/easy.hpp
index 3d6e52d5c379..91e714d66626 100644
--- a/libraries/easy/include/userver/easy.hpp
+++ b/libraries/easy/include/userver/easy.hpp
@@ -1,11 +1,15 @@
 #pragma once
 
+/// @file userver/easy.hpp
+/// @brief Headers of an library for `easy` prototyping
+
 #include <functional>
 #include <string>
 #include <string_view>
 
 #include <userver/components/component_base.hpp>
 #include <userver/components/component_list.hpp>
+#include <userver/formats/json.hpp>
 #include <userver/http/content_type.hpp>
 #include <userver/server/http/http_request.hpp>
 #include <userver/server/request/request_context.hpp>
@@ -17,38 +21,58 @@ USERVER_NAMESPACE_BEGIN
 /// @brief Top namespace for `easy` library
 namespace easy {
 
+/// @brief Base class for all the dependencies of the `easy` library.
 class DependenciesBase : public components::ComponentBase {
 public:
     static constexpr std::string_view kName = "easy-dependencies";
     using components::ComponentBase::ComponentBase;
     virtual ~DependenciesBase();
 
+    /// @returns the \b last schema that was provided to the easy::HttpWith or easy::HttpBase
     static const std::string& GetSchema() noexcept;
 };
 
+/// @brief Tag for custom Dependency registration customization.
+///
+/// For a new dependency type `Dependency` a function `void Registration(OfDependency<Dependency>, HttpBase& app)`
+/// should be provided to be able to use that dependency with the easy::HttpWith class.
 template <class Dependency>
 struct OfDependency final {};
 
+/// @brief easy::HttpWith like class with erased dependencies information that should be used only in dependency
+/// registration functions; use easy::HttpWith if not making a new dependency class.
 class HttpBase final {
 public:
     using Callback = std::function<std::string(const server::http::HttpRequest&, const DependenciesBase&)>;
 
+    /// Sets the default Content-Type header for all the routes
     void DefaultContentType(http::ContentType content_type);
+
+    /// Register an HTTP handler by `path` that supports the `methods` HTTP methods
     void Route(std::string_view path, Callback&& func, std::initializer_list<server::http::HttpMethod> methods);
 
+    /// Add a comonent config to the service config
     void AddComponentsConfig(std::string_view config);
 
+    /// Append a component to the component list of a service
     template <class Component>
     void AppendComponent(std::string_view name) {
         component_list_.Append<Component>(name);
     }
+
+    /// @overload
     template <class Component>
     void AppendComponent() {
         component_list_.Append<Component>();
     }
 
+    /// Stores the schema for further retrieval from DependenciesBase::GetSchema()
     void Schema(std::string_view schema);
+
+    /// Set the HTTP server listen port, default is 8080.
     void Port(std::uint16_t port);
+
+    /// Set the logging level for the service
     void LogLevel(logging::Level level);
 
 private:
@@ -69,9 +93,23 @@ class HttpBase final {
     logging::Level level_ = logging::Level::kDebug;
 };
 
+/// @brief Class for describing the service functionality in simple declarative way that generates static configs,
+/// applies schemas.
+///
+/// @see @ref scripts/docs/en/userver/libraries/easy.md
 template <class Dependency = DependenciesBase>
 class HttpWith final {
 public:
+    /// Helper class that can store any callback of the following signatures:
+    ///
+    /// * formats::json::Value(formats::json::Value, const Dependency&)
+    /// * formats::json::Value(formats::json::Value)
+    /// * formats::json::Value(const HttpRequest&, const Dependency&)
+    /// * std::string(const HttpRequest&, const Dependency&)
+    /// * formats::json::Value(const HttpRequest&)
+    /// * std::string(const HttpRequest&)
+    ///
+    /// If callback returns formats::json::Value then the deafult content type is set to `application/json`
     class Callback final {
     public:
         template <class Function>
@@ -86,10 +124,12 @@ class HttpWith final {
     HttpWith(int argc, const char* const argv[]) : impl_(argc, argv) { impl_.AppendComponent<Dependency>(); }
     ~HttpWith() { Registration(OfDependency<Dependency>{}, impl_); /* ADL is intentional */ }
 
+    /// @copydoc HttpBase::DefaultContentType
     HttpWith& DefaultContentType(http::ContentType content_type) {
         return (impl_.DefaultContentType(content_type), *this);
     }
 
+    /// @copydoc HttpBase::Route
     HttpWith& Route(
         std::string_view path,
         Callback&& func,
@@ -106,58 +146,69 @@ class HttpWith final {
         return *this;
     }
 
+    /// Register an HTTP handler by `path` that supports the HTTP GET method.
     HttpWith& Get(std::string_view path, Callback&& func) {
         impl_.Route(path, std::move(func).Extract(), {server::http::HttpMethod::kGet});
         return *this;
     }
 
+    /// Register an HTTP handler by `path` that supports the HTTP POST method.
     HttpWith& Post(std::string_view path, Callback&& func) {
         impl_.Route(path, std::move(func).Extract(), {server::http::HttpMethod::kPost});
         return *this;
     }
 
+    /// Register an HTTP handler by `path` that supports the HTTP DELETE method.
     HttpWith& Del(std::string_view path, Callback&& func) {
         impl_.Route(path, std::move(func).Extract(), {server::http::HttpMethod::kDelete});
         return *this;
     }
 
+    /// Register an HTTP handler by `path` that supports the HTTP PUT method.
     HttpWith& Put(std::string_view path, Callback&& func) {
         impl_.Route(path, std::move(func).Extract(), {server::http::HttpMethod::kPut});
         return *this;
     }
 
+    /// Register an HTTP handler by `path` that supports the HTTP PATCH method.
     HttpWith& Patch(std::string_view path, Callback&& func) {
         impl_.Route(path, std::move(func).Extract(), {server::http::HttpMethod::kPatch});
         return *this;
     }
 
+    /// @copydoc HttpBase::AddComponentsConfig
     HttpWith& AddComponentsConfig(std::string_view config) {
         impl_.AddComponentsConfig(config);
         return *this;
     }
 
+    /// @copydoc HttpBase::AppendComponent
     template <class Component>
     HttpWith& AppendComponent(std::string_view name) {
         impl_.AppendComponent<Component>(name);
         return *this;
     }
 
+    /// @copydoc HttpBase::AppendComponent
     template <class Component>
     HttpWith& AppendComponent() {
         impl_.AppendComponent<Component>();
         return *this;
     }
 
+    /// @copydoc HttpBase::Schema
     HttpWith& Schema(std::string_view schema) {
         impl_.Schema(schema);
         return *this;
     }
 
+    /// @copydoc HttpBase::Port
     HttpWith& Port(std::uint16_t port) {
         impl_.Port(port);
         return *this;
     }
 
+    /// @copydoc HttpBase::LogLevel
     HttpWith& LogLevel(logging::Level level) {
         impl_.LogLevel(level);
         return *this;
@@ -184,18 +235,40 @@ template <class Dependency>
 template <class Function>
 HttpWith<Dependency>::Callback::Callback(Function func) {
     using server::http::HttpRequest;
-    if constexpr (std::is_invocable_r_v<std::string, Function, const HttpRequest&, const Dependency&>) {
+
+    if constexpr (std::is_invocable_r_v<formats::json::Value, Function, formats::json::Value, const Dependency&>) {
+        func_ = [f = std::move(func)](const HttpRequest& req, const DependenciesBase& deps) {
+            req.GetHttpResponse().SetContentType(http::content_type::kApplicationJson);
+            return formats::json::ToString(
+                f(formats::json::FromString(req.RequestBody()), static_cast<const Dependency&>(deps))
+            );
+        };
+    } else if constexpr (std::is_invocable_r_v<formats::json::Value, Function, formats::json::Value>) {
+        func_ = [f = std::move(func)](const HttpRequest& req, const DependenciesBase&) {
+            req.GetHttpResponse().SetContentType(http::content_type::kApplicationJson);
+            return formats::json::ToString(f(formats::json::FromString(req.RequestBody())));
+        };
+    } else if constexpr (std::is_invocable_r_v<formats::json::Value, Function, const HttpRequest&, const Dependency&>) {
+        func_ = [f = std::move(func)](const HttpRequest& req, const DependenciesBase& deps) {
+            req.GetHttpResponse().SetContentType(http::content_type::kApplicationJson);
+            return formats::json::ToString(f(req, static_cast<const Dependency&>(deps)));
+        };
+    } else if constexpr (std::is_invocable_r_v<std::string, Function, const HttpRequest&, const Dependency&>) {
         func_ = [f = std::move(func)](const HttpRequest& req, const DependenciesBase& deps) {
             return f(req, static_cast<const Dependency&>(deps));
         };
-    } else if constexpr (std::is_invocable_r_v<std::string, Function, const HttpRequest&, const DependenciesBase&>) {
-        func_ = std::move(func);
+    } else if constexpr (std::is_invocable_r_v<formats::json::Value, Function, const HttpRequest&>) {
+        func_ = [f = std::move(func)](const HttpRequest& req, const DependenciesBase&) {
+            req.GetHttpResponse().SetContentType(http::content_type::kApplicationJson);
+            return formats::json::ToString(f(req));
+        };
     } else {
         static_assert(std::is_invocable_r_v<std::string, Function, const HttpRequest&>);
         func_ = [f = std::move(func)](const HttpRequest& req, const DependenciesBase&) { return f(req); };
     }
 }
 
+/// @brief Predefined dependencies class that provides a PostgreSQL cluster client.
 class PgDep : public DependenciesBase {
 public:
     PgDep(const components::ComponentConfig& config, const components::ComponentContext& context);
diff --git a/libraries/easy/samples/3_json/CMakeLists.txt b/libraries/easy/samples/3_json/CMakeLists.txt
new file mode 100644
index 000000000000..5be1c72c727d
--- /dev/null
+++ b/libraries/easy/samples/3_json/CMakeLists.txt
@@ -0,0 +1,24 @@
+project(userver-easy-samples-json CXX)
+
+file(GLOB_RECURSE SCHEMAS ${CMAKE_CURRENT_SOURCE_DIR}/schemas/*.yaml)
+userver_target_generate_chaotic(${PROJECT_NAME}-chgen
+    ARGS
+        # Map '/components/schemas/*' JSONSchema types to C++ types in 'schemas' namespace
+        -n "/components/schemas/([^/]*)/=schemas::{0}"
+        -f "(.*)={0}"
+        # Don't call clang-format
+        --clang-format=
+        # Generate serializers for responses
+        --generate-serializers
+    OUTPUT_DIR
+        ${CMAKE_CURRENT_BINARY_DIR}/src
+    SCHEMAS
+        ${SCHEMAS}
+    RELATIVE_TO
+        ${CMAKE_CURRENT_SOURCE_DIR}
+)
+
+add_executable(${PROJECT_NAME} "main.cpp")
+target_link_libraries(${PROJECT_NAME} userver::easy ${PROJECT_NAME}-chgen)
+
+userver_testsuite_add_simple(DUMP_CONFIG True)
diff --git a/libraries/easy/samples/3_json/main.cpp b/libraries/easy/samples/3_json/main.cpp
new file mode 100644
index 000000000000..e93be32d3ad8
--- /dev/null
+++ b/libraries/easy/samples/3_json/main.cpp
@@ -0,0 +1,44 @@
+// Note: this is for the purposes of samples only
+#include <userver/utest/using_namespace_userver.hpp>
+
+#include <userver/easy.hpp>
+#include "schemas/key_value.hpp"
+
+constexpr std::string_view kSchema = R"~(
+CREATE TABLE IF NOT EXISTS key_value_table (
+	key integer PRIMARY KEY,
+	value VARCHAR
+)
+)~";
+
+int main(int argc, char* argv[]) {
+    easy::HttpWith<easy::PgDep>(argc, argv)
+        .Schema(kSchema)
+        .Get(
+            "/kv",
+            [](formats::json::Value request_json, const easy::PgDep& dep) {
+                // Use generated parser for As()
+                auto key = request_json.As<schemas::KeyRequest>().key;
+
+                auto res = dep.pg().Execute(
+                    storages::postgres::ClusterHostType::kSlave, "SELECT value FROM key_value_table WHERE key=$1", key
+                );
+
+                schemas::KeyValue response{key, res[0][0].As<std::string>()};
+                return formats::json::ValueBuilder{response}.ExtractValue();
+            }
+        )
+        .Post("/kv", [](formats::json::Value request_json, const auto& dep) {
+            // Use generated parser for As()
+            auto key_value = request_json.As<schemas::KeyValue>();
+
+            dep.pg().Execute(
+                storages::postgres::ClusterHostType::kMaster,
+                "INSERT INTO key_value_table(key, value) VALUES($1, $2) ON CONFLICT (key) DO UPDATE SET value = $2",
+                key_value.key,
+                key_value.value
+            );
+
+            return formats::json::Value{};
+        });
+}
diff --git a/libraries/easy/samples/3_json/schemas/key_value.yaml b/libraries/easy/samples/3_json/schemas/key_value.yaml
new file mode 100644
index 000000000000..a4e3bb84433d
--- /dev/null
+++ b/libraries/easy/samples/3_json/schemas/key_value.yaml
@@ -0,0 +1,17 @@
+# yaml
+components:
+    schemas:
+        KeyRequest:
+            type: object
+            additionalProperties: false
+            properties:
+                key:
+                    type: integer
+        KeyValue:
+            type: object
+            additionalProperties: false
+            properties:
+                key:
+                    type: integer
+                value:
+                    type: string
diff --git a/libraries/easy/samples/3_custom_dependency/tests/conftest.py b/libraries/easy/samples/3_json/tests/conftest.py
similarity index 100%
rename from libraries/easy/samples/3_custom_dependency/tests/conftest.py
rename to libraries/easy/samples/3_json/tests/conftest.py
diff --git a/libraries/easy/samples/3_json/tests/test_basic.py b/libraries/easy/samples/3_json/tests/test_basic.py
new file mode 100644
index 000000000000..1d4548f74d4c
--- /dev/null
+++ b/libraries/easy/samples/3_json/tests/test_basic.py
@@ -0,0 +1,18 @@
+async def test_kv(service_client):
+    response = await service_client.post("/kv", json={"key": 1, "value": "one"})
+    assert response.status == 200
+    assert response.json() == None
+    assert "application/json" in response.headers["Content-Type"]
+
+    response = await service_client.get("/kv", json={"key": 1})
+    assert response.status == 200
+    assert response.json() == {"key": 1, "value": "one"}
+    assert "application/json" in response.headers["Content-Type"]
+
+    response = await service_client.post("/kv", json={"key": 1, "value": "again_1"})
+    assert response.status == 200
+
+    response = await service_client.get("/kv", json={"key": 1})
+    assert response.status == 200
+    assert response.json() == {"key": 1, "value": "again_1"}
+    assert "application/json" in response.headers["Content-Type"]
diff --git a/libraries/easy/samples/3_custom_dependency/CMakeLists.txt b/libraries/easy/samples/4_custom_dependency/CMakeLists.txt
similarity index 100%
rename from libraries/easy/samples/3_custom_dependency/CMakeLists.txt
rename to libraries/easy/samples/4_custom_dependency/CMakeLists.txt
diff --git a/libraries/easy/samples/3_custom_dependency/main.cpp b/libraries/easy/samples/4_custom_dependency/main.cpp
similarity index 100%
rename from libraries/easy/samples/3_custom_dependency/main.cpp
rename to libraries/easy/samples/4_custom_dependency/main.cpp
diff --git a/libraries/easy/samples/4_custom_dependency/tests/conftest.py b/libraries/easy/samples/4_custom_dependency/tests/conftest.py
new file mode 100644
index 000000000000..2a91ee35c675
--- /dev/null
+++ b/libraries/easy/samples/4_custom_dependency/tests/conftest.py
@@ -0,0 +1,18 @@
+# /// [psql prepare]
+import os
+import pytest
+import subprocess
+
+from testsuite.databases.pgsql import discover
+
+pytest_plugins = ["pytest_userver.plugins.postgresql"]
+
+
+@pytest.fixture(scope="session")
+def pgsql_local(service_tmpdir, service_binary, pgsql_local_create):
+    schema_path = service_tmpdir.joinpath("schemas")
+    os.mkdir(schema_path)
+    subprocess.run([service_binary, "--dump-schema", schema_path])
+    databases = discover.find_schemas("admin", [schema_path])
+    return pgsql_local_create(list(databases.values()))
+    # /// [psql prepare]
diff --git a/libraries/easy/samples/3_custom_dependency/tests/test_basic.py b/libraries/easy/samples/4_custom_dependency/tests/test_basic.py
similarity index 100%
rename from libraries/easy/samples/3_custom_dependency/tests/test_basic.py
rename to libraries/easy/samples/4_custom_dependency/tests/test_basic.py
diff --git a/libraries/easy/samples/CMakeLists.txt b/libraries/easy/samples/CMakeLists.txt
index ee07b23e857a..55d49fd9b942 100644
--- a/libraries/easy/samples/CMakeLists.txt
+++ b/libraries/easy/samples/CMakeLists.txt
@@ -11,5 +11,8 @@ add_dependencies(${PROJECT_NAME} ${PROJECT_NAME}-hi)
 add_subdirectory(2_key_value)
 add_dependencies(${PROJECT_NAME} ${PROJECT_NAME}-key-value)
 
-add_subdirectory(3_custom_dependency)
+add_subdirectory(3_json)
+add_dependencies(${PROJECT_NAME} ${PROJECT_NAME}-json)
+
+add_subdirectory(4_custom_dependency)
 add_dependencies(${PROJECT_NAME} ${PROJECT_NAME}-custom-dependency)

From d9f0cc62918a1dc8c3da5c2f00e55bd54d7fd40f Mon Sep 17 00:00:00 2001
From: Antony Polukhin <antoshkka@gmail.com>
Date: Fri, 29 Nov 2024 11:41:22 +0300
Subject: [PATCH 17/19] Better integration with core

---
 core/include/userver/utils/daemon_run.hpp | 18 ++++++--
 core/src/utils/daemon_run.cpp             | 54 +++++++++++++----------
 libraries/easy/src/easy.cpp               | 15 ++++---
 3 files changed, 56 insertions(+), 31 deletions(-)

diff --git a/core/include/userver/utils/daemon_run.hpp b/core/include/userver/utils/daemon_run.hpp
index 768d9abf5b59..4f54aa5aaeb8 100644
--- a/core/include/userver/utils/daemon_run.hpp
+++ b/core/include/userver/utils/daemon_run.hpp
@@ -5,22 +5,34 @@
 
 #include <userver/components/component_list.hpp>
 
+
+namespace boost::program_options {
+class options_description;
+class variables_map;
+}
+
 USERVER_NAMESPACE_BEGIN
 
 namespace utils {
 
-/// Parses command line arguments and calls components::Run with config file
-/// from --config parameter.
+/// @returns default options of DaemonMain
 ///
-/// Other command line arguments:
+/// List of options:
 /// * --help - show all command line arguments
 /// * --config CONFIG - path to config.yaml
 /// * --config_vars CONFIG_VARS - path to config_vars.yaml
 /// * --config_vars_override CONFIG_VARS - path to config_vars.override.yaml
 /// * --print-config-schema - print config.yaml YAML Schema
 /// * --print-dynamic-config-defaults - print JSON with dynamic config defaults
+boost::program_options::options_description BaseRunOptions();
+
+/// Parses command line arguments and calls components::Run with config file
+/// from --config parameter. See BaseRunOptions() for a list of options
 int DaemonMain(int argc, const char* const argv[], const components::ComponentList& components_list);
 
+/// @overload
+int DaemonMain(const boost::program_options::variables_map& vm, const components::ComponentList& components_list);
+
 }  // namespace utils
 
 USERVER_NAMESPACE_END
diff --git a/core/src/utils/daemon_run.cpp b/core/src/utils/daemon_run.cpp
index e3e9c4d1d7b2..d023bf1ea96a 100644
--- a/core/src/utils/daemon_run.cpp
+++ b/core/src/utils/daemon_run.cpp
@@ -15,36 +15,38 @@ namespace utils {
 
 namespace {
 
-std::optional<std::string> ToOptional(std::string&& s) {
-    if (s.empty())
+template <class Value>
+std::optional<std::string> ToOptional(const Value& val) {
+    if (val.empty())
         return {};
     else
-        return {std::move(s)};
+        return {val.template as<std::string>()};
 }
 
 }  // namespace
 
-int DaemonMain(const int argc, const char* const argv[], const components::ComponentList& components_list) {
-    utils::impl::FinishStaticRegistration();
-
+boost::program_options::options_description BaseRunOptions() {
     namespace po = boost::program_options;
-
-    po::variables_map vm;
     po::options_description desc("Allowed options");
-    std::string config_path;
-    std::string config_vars_path;
-    std::string config_vars_override_path;
-
     // clang-format off
-  desc.add_options()
-    ("help,h", "produce this help message")
-    ("print-config-schema", "print config.yaml YAML Schema")
-    ("print-dynamic-config-defaults", "print JSON object with dynamic config defaults")
-    ("config,c", po::value(&config_path)->required(), "path to server config")
-    ("config_vars", po::value(&config_vars_path), "path to config_vars.yaml; if set, config_vars in config.yaml are ignored")
-    ("config_vars_override", po::value(&config_vars_override_path), "path to an additional config_vars.yaml, which overrides vars of config_vars.yaml")
-  ;
+    desc.add_options()
+        ("help,h", "produce this help message")
+        ("print-config-schema", "print config.yaml YAML Schema")
+        ("print-dynamic-config-defaults", "print JSON object with dynamic config defaults")
+        ("config_vars", po::value<std::string>(), "path to config_vars.yaml; if set, config_vars in config.yaml are ignored")
+        ("config_vars_override", po::value<std::string>(), "path to an additional config_vars.yaml, which overrides vars of config_vars.yaml")
+    ;
     // clang-format on
+return desc;
+}
+
+int DaemonMain(const int argc, const char* const argv[], const components::ComponentList& components_list) {
+    namespace po = boost::program_options;
+    po::variables_map vm;
+    auto desc = BaseRunOptions();
+    desc.add_options()
+        ("config,c", po::value<std::string>()->required(), "path to server config")
+    ;
 
     try {
         po::store(po::parse_command_line(argc, argv, desc), vm);
@@ -59,6 +61,12 @@ int DaemonMain(const int argc, const char* const argv[], const components::Compo
         return 0;
     }
 
+    return DaemonMain(vm, components_list);
+}
+
+int DaemonMain(const boost::program_options::variables_map& vm, const components::ComponentList& components_list) {
+    utils::impl::FinishStaticRegistration();
+
     if (vm.count("print-config-schema")) {
         std::cout << components::impl::GetStaticConfigSchema(components_list) << "\n";
         return 0;
@@ -71,9 +79,9 @@ int DaemonMain(const int argc, const char* const argv[], const components::Compo
 
     try {
         components::Run(
-            config_path,
-            ToOptional(std::move(config_vars_path)),
-            ToOptional(std::move(config_vars_override_path)),
+            vm["config"].as<std::string>(),
+            ToOptional(vm["config_vars"]),
+            ToOptional(vm["config_vars_override"]),
             components_list
         );
         return 0;
diff --git a/libraries/easy/src/easy.cpp b/libraries/easy/src/easy.cpp
index d461a8c22479..17ecca90e4fc 100644
--- a/libraries/easy/src/easy.cpp
+++ b/libraries/easy/src/easy.cpp
@@ -1,6 +1,7 @@
 #include <userver/easy.hpp>
 
 #include <fstream>
+#include <iostream>
 #include <unordered_map>
 
 #include <boost/algorithm/string/replace.hpp>
@@ -104,9 +105,8 @@ HttpBase::~HttpBase() {
     AddComponentsConfig(fmt::format(kConfigLoggingTemplate, ToString(level_)));
 
     namespace po = boost::program_options;
-
     po::variables_map vm;
-    po::options_description desc("Easy options");
+    auto desc = utils::BaseRunOptions();
     std::string config_dump;
     std::string schema_dump;
 
@@ -114,12 +114,18 @@ HttpBase::~HttpBase() {
     desc.add_options()
       ("dump-config", po::value(&config_dump), "path to dump the server config")
       ("dump-schema", po::value(&schema_dump), "path to dump the DB schema")
+      ("config,c", po::value<std::string>(), "path to server config")
     ;
     // clang-format on
 
-    po::store(po::command_line_parser(argc_, argv_).options(desc).allow_unregistered().run(), vm);
+    po::store(po::parse_command_line(argc_, argv_, desc), vm);
     po::notify(vm);
 
+    if (vm.count("help")) {
+        std::cerr << desc << '\n';
+        return;
+    }
+
     if (vm.count("dump-config")) {
         std::ofstream(config_dump) << static_config_;
         return;
@@ -131,9 +137,8 @@ HttpBase::~HttpBase() {
 
     if (argc_ <= 1) {
         components::Run(components::InMemoryConfig{static_config_}, component_list_);
-        return;
     } else {
-        const auto ret = utils::DaemonMain(argc_, argv_, component_list_);
+        const auto ret = utils::DaemonMain(vm, component_list_);
         if (ret != 0) {
             std::exit(ret);
         }

From adb286cec8d7ef9a94daae06bc0a8081c1d0b777 Mon Sep 17 00:00:00 2001
From: Antony Polukhin <antoshkka@gmail.com>
Date: Sun, 1 Dec 2024 17:27:18 +0300
Subject: [PATCH 18/19] review fixes

---
 libraries/easy/include/userver/easy.hpp       | 178 ++++++++++--------
 libraries/easy/samples/2_key_value/main.cpp   |   2 +-
 .../samples/2_key_value/tests/conftest.py     |  13 +-
 libraries/easy/samples/3_json/main.cpp        |   4 +-
 .../easy/samples/3_json/tests/conftest.py     |  17 +-
 .../easy/samples/4_custom_dependency/main.cpp |  73 ++++---
 .../4_custom_dependency/tests/conftest.py     |  28 ++-
 .../4_custom_dependency/tests/test_basic.py   |  10 +-
 libraries/easy/src/easy.cpp                   | 124 ++++++------
 9 files changed, 261 insertions(+), 188 deletions(-)

diff --git a/libraries/easy/include/userver/easy.hpp b/libraries/easy/include/userver/easy.hpp
index 91e714d66626..4f1d104a0e5b 100644
--- a/libraries/easy/include/userver/easy.hpp
+++ b/libraries/easy/include/userver/easy.hpp
@@ -7,6 +7,7 @@
 #include <string>
 #include <string_view>
 
+#include <userver/clients/http/client.hpp>
 #include <userver/components/component_base.hpp>
 #include <userver/components/component_list.hpp>
 #include <userver/formats/json.hpp>
@@ -21,29 +22,22 @@ USERVER_NAMESPACE_BEGIN
 /// @brief Top namespace for `easy` library
 namespace easy {
 
-/// @brief Base class for all the dependencies of the `easy` library.
+namespace impl {
+
 class DependenciesBase : public components::ComponentBase {
 public:
     static constexpr std::string_view kName = "easy-dependencies";
     using components::ComponentBase::ComponentBase;
     virtual ~DependenciesBase();
-
-    /// @returns the \b last schema that was provided to the easy::HttpWith or easy::HttpBase
-    static const std::string& GetSchema() noexcept;
 };
 
-/// @brief Tag for custom Dependency registration customization.
-///
-/// For a new dependency type `Dependency` a function `void Registration(OfDependency<Dependency>, HttpBase& app)`
-/// should be provided to be able to use that dependency with the easy::HttpWith class.
-template <class Dependency>
-struct OfDependency final {};
+}  // namespace impl
 
 /// @brief easy::HttpWith like class with erased dependencies information that should be used only in dependency
 /// registration functions; use easy::HttpWith if not making a new dependency class.
 class HttpBase final {
 public:
-    using Callback = std::function<std::string(const server::http::HttpRequest&, const DependenciesBase&)>;
+    using Callback = std::function<std::string(const server::http::HttpRequest&, const impl::DependenciesBase&)>;
 
     /// Sets the default Content-Type header for all the routes
     void DefaultContentType(http::ContentType content_type);
@@ -51,23 +45,33 @@ class HttpBase final {
     /// Register an HTTP handler by `path` that supports the `methods` HTTP methods
     void Route(std::string_view path, Callback&& func, std::initializer_list<server::http::HttpMethod> methods);
 
-    /// Add a comonent config to the service config
-    void AddComponentsConfig(std::string_view config);
-
     /// Append a component to the component list of a service
     template <class Component>
-    void AppendComponent(std::string_view name) {
+    bool TryAddComponent(std::string_view name, std::string_view config) {
+        if (component_list_.Contains(name)) {
+            return false;
+        }
+
         component_list_.Append<Component>(name);
+        AddComponentConfig(name, config);
+        return true;
     }
 
-    /// @overload
     template <class Component>
-    void AppendComponent() {
-        component_list_.Append<Component>();
+    bool TryAddComponent(std::string_view name) {
+        if (component_list_.Contains(name)) {
+            return false;
+        }
+
+        component_list_.Append<Component>(name);
+        return true;
     }
 
-    /// Stores the schema for further retrieval from DependenciesBase::GetSchema()
-    void Schema(std::string_view schema);
+    /// Stores the schema for further retrieval from GetDbSchema()
+    void DbSchema(std::string_view schema);
+
+    /// @returns the \b last schema that was provided to the easy::HttpWith or easy::HttpBase
+    static const std::string& GetDbSchema() noexcept;
 
     /// Set the HTTP server listen port, default is 8080.
     void Port(std::uint16_t port);
@@ -79,6 +83,8 @@ class HttpBase final {
     template <class>
     friend class HttpWith;
 
+    void AddComponentConfig(std::string_view name, std::string_view config);
+
     HttpBase(int argc, const char* const argv[]);
     ~HttpBase();
 
@@ -93,13 +99,27 @@ class HttpBase final {
     logging::Level level_ = logging::Level::kDebug;
 };
 
+/// Class that combines dependencies passed to HttpWith into a single type, that is passed to callbacks.
+///
+/// @see @ref scripts/docs/en/userver/libraries/easy.md
+template <class... Dependency>
+class Dependencies final : public impl::DependenciesBase, public Dependency... {
+public:
+    Dependencies(const components::ComponentConfig& config, const components::ComponentContext& context)
+        : DependenciesBase{config, context}, Dependency{context}... {}
+
+    static void RegisterOn(HttpBase& app) { (Dependency::RegisterOn(app), ...); }
+};
+
 /// @brief Class for describing the service functionality in simple declarative way that generates static configs,
 /// applies schemas.
 ///
 /// @see @ref scripts/docs/en/userver/libraries/easy.md
-template <class Dependency = DependenciesBase>
+template <class Deps = Dependencies<>>
 class HttpWith final {
 public:
+    using Dependency = std::conditional_t<std::is_base_of_v<impl::DependenciesBase, Deps>, Deps, Dependencies<Deps>>;
+
     /// Helper class that can store any callback of the following signatures:
     ///
     /// * formats::json::Value(formats::json::Value, const Dependency&)
@@ -121,8 +141,10 @@ class HttpWith final {
         HttpBase::Callback func_;
     };
 
-    HttpWith(int argc, const char* const argv[]) : impl_(argc, argv) { impl_.AppendComponent<Dependency>(); }
-    ~HttpWith() { Registration(OfDependency<Dependency>{}, impl_); /* ADL is intentional */ }
+    HttpWith(int argc, const char* const argv[]) : impl_(argc, argv) {
+        impl_.TryAddComponent<Dependency>(Dependency::kName);
+    }
+    ~HttpWith() { Dependency::RegisterOn(impl_); }
 
     /// @copydoc HttpBase::DefaultContentType
     HttpWith& DefaultContentType(http::ContentType content_type) {
@@ -176,29 +198,9 @@ class HttpWith final {
         return *this;
     }
 
-    /// @copydoc HttpBase::AddComponentsConfig
-    HttpWith& AddComponentsConfig(std::string_view config) {
-        impl_.AddComponentsConfig(config);
-        return *this;
-    }
-
-    /// @copydoc HttpBase::AppendComponent
-    template <class Component>
-    HttpWith& AppendComponent(std::string_view name) {
-        impl_.AppendComponent<Component>(name);
-        return *this;
-    }
-
-    /// @copydoc HttpBase::AppendComponent
-    template <class Component>
-    HttpWith& AppendComponent() {
-        impl_.AppendComponent<Component>();
-        return *this;
-    }
-
     /// @copydoc HttpBase::Schema
-    HttpWith& Schema(std::string_view schema) {
-        impl_.Schema(schema);
+    HttpWith& DbSchema(std::string_view schema) {
+        impl_.DbSchema(schema);
         return *this;
     }
 
@@ -218,75 +220,87 @@ class HttpWith final {
     HttpBase impl_;
 };
 
-template <class T, class HttpBase>
-inline void Registration(T, HttpBase&&) {
-    static_assert(
-        sizeof(T) && false,
-        "Define `void Registration(easy::OfDependency<T>, HttpBase& app)` "
-        "in the namespace of the your dependency type `T` to automatically add required configurations and "
-        "components to the `app`.  For example:"
-        "void Registration(easy::OfDependency<MyDeps>, easy::HttpBase& app) { app.AppendComponent<MyComponent>(); }"
-    );
-}
-
-inline void Registration(OfDependency<DependenciesBase>, HttpBase&) {}
-
-template <class Dependency>
+template <class Deps>
 template <class Function>
-HttpWith<Dependency>::Callback::Callback(Function func) {
+HttpWith<Deps>::Callback::Callback(Function func) {
     using server::http::HttpRequest;
 
-    if constexpr (std::is_invocable_r_v<formats::json::Value, Function, formats::json::Value, const Dependency&>) {
-        func_ = [f = std::move(func)](const HttpRequest& req, const DependenciesBase& deps) {
+    constexpr unsigned kMatches =
+        (std::is_invocable_r_v<formats::json::Value, Function, formats::json::Value, const Dependency&> << 0) |
+        (std::is_invocable_r_v<formats::json::Value, Function, formats::json::Value> << 1) |
+        (std::is_invocable_r_v<formats::json::Value, Function, const HttpRequest&, const Dependency&> << 2) |
+        (std::is_invocable_r_v<std::string, Function, const HttpRequest&, const Dependency&> << 3) |
+        (std::is_invocable_r_v<formats::json::Value, Function, const HttpRequest&> << 4) |
+        (std::is_invocable_r_v<std::string, Function, const HttpRequest&> << 5);
+    static_assert(
+        kMatches,
+        "Failed to find a matching signature. See the easy::HttpWith::Callback docs for info on "
+        "supported signatures"
+    );
+    constexpr bool has_single_match = ((kMatches & (kMatches - 1)) == 0);
+    static_assert(
+        has_single_match,
+        "Found more than one matching signature, probably due to `auto` usage in parameters. See "
+        "the easy::HttpWith::Callback docs for info on supported signatures"
+    );
+
+    if constexpr (kMatches & 1) {
+        func_ = [f = std::move(func)](const HttpRequest& req, const impl::DependenciesBase& deps) {
             req.GetHttpResponse().SetContentType(http::content_type::kApplicationJson);
             return formats::json::ToString(
                 f(formats::json::FromString(req.RequestBody()), static_cast<const Dependency&>(deps))
             );
         };
-    } else if constexpr (std::is_invocable_r_v<formats::json::Value, Function, formats::json::Value>) {
-        func_ = [f = std::move(func)](const HttpRequest& req, const DependenciesBase&) {
+    } else if constexpr (kMatches & 2) {
+        func_ = [f = std::move(func)](const HttpRequest& req, const impl::DependenciesBase&) {
             req.GetHttpResponse().SetContentType(http::content_type::kApplicationJson);
             return formats::json::ToString(f(formats::json::FromString(req.RequestBody())));
         };
-    } else if constexpr (std::is_invocable_r_v<formats::json::Value, Function, const HttpRequest&, const Dependency&>) {
-        func_ = [f = std::move(func)](const HttpRequest& req, const DependenciesBase& deps) {
+    } else if constexpr (kMatches & 4) {
+        func_ = [f = std::move(func)](const HttpRequest& req, const impl::DependenciesBase& deps) {
             req.GetHttpResponse().SetContentType(http::content_type::kApplicationJson);
             return formats::json::ToString(f(req, static_cast<const Dependency&>(deps)));
         };
-    } else if constexpr (std::is_invocable_r_v<std::string, Function, const HttpRequest&, const Dependency&>) {
-        func_ = [f = std::move(func)](const HttpRequest& req, const DependenciesBase& deps) {
+    } else if constexpr (kMatches & 8) {
+        func_ = [f = std::move(func)](const HttpRequest& req, const impl::DependenciesBase& deps) {
             return f(req, static_cast<const Dependency&>(deps));
         };
-    } else if constexpr (std::is_invocable_r_v<formats::json::Value, Function, const HttpRequest&>) {
-        func_ = [f = std::move(func)](const HttpRequest& req, const DependenciesBase&) {
+    } else if constexpr (kMatches & 16) {
+        func_ = [f = std::move(func)](const HttpRequest& req, const impl::DependenciesBase&) {
             req.GetHttpResponse().SetContentType(http::content_type::kApplicationJson);
             return formats::json::ToString(f(req));
         };
     } else {
-        static_assert(std::is_invocable_r_v<std::string, Function, const HttpRequest&>);
-        func_ = [f = std::move(func)](const HttpRequest& req, const DependenciesBase&) { return f(req); };
+        static_assert(kMatches & 32);
+        func_ = [f = std::move(func)](const HttpRequest& req, const impl::DependenciesBase&) { return f(req); };
     }
 }
 
-/// @brief Predefined dependencies class that provides a PostgreSQL cluster client.
-class PgDep : public DependenciesBase {
+/// @brief Dependency class that provides a PostgreSQL cluster client.
+class PgDep {
 public:
-    PgDep(const components::ComponentConfig& config, const components::ComponentContext& context);
-
+    explicit PgDep(const components::ComponentContext& context);
     storages::postgres::Cluster& pg() const noexcept { return *pg_cluster_; }
+    static void RegisterOn(HttpBase& app);
 
 private:
     storages::postgres::ClusterPtr pg_cluster_;
 };
 
-void Registration(OfDependency<PgDep>, HttpBase& app);
+/// @brief Dependency class that provides a Http client.
+class HttpDep {
+public:
+    explicit HttpDep(const components::ComponentContext& context);
+    clients::http::Client& http() { return http_; }
+    static void RegisterOn(HttpBase& app);
 
-}  // namespace easy
+private:
+    clients::http::Client& http_;
+};
 
-template <>
-inline constexpr auto components::kConfigFileMode<easy::DependenciesBase> = ConfigFileMode::kNotRequired;
+}  // namespace easy
 
-template <>
-inline constexpr auto components::kConfigFileMode<easy::PgDep> = ConfigFileMode::kNotRequired;
+template <class... Components>
+inline constexpr auto components::kConfigFileMode<easy::Dependencies<Components...>> = ConfigFileMode::kNotRequired;
 
 USERVER_NAMESPACE_END
diff --git a/libraries/easy/samples/2_key_value/main.cpp b/libraries/easy/samples/2_key_value/main.cpp
index cf8967422e8a..309678a5d2a5 100644
--- a/libraries/easy/samples/2_key_value/main.cpp
+++ b/libraries/easy/samples/2_key_value/main.cpp
@@ -12,7 +12,7 @@ CREATE TABLE IF NOT EXISTS key_value_table (
 
 int main(int argc, char* argv[]) {
     easy::HttpWith<easy::PgDep>(argc, argv)
-        .Schema(kSchema)
+        .DbSchema(kSchema)
         .DefaultContentType(http::content_type::kTextPlain)
         .Get(
             "/kv",
diff --git a/libraries/easy/samples/2_key_value/tests/conftest.py b/libraries/easy/samples/2_key_value/tests/conftest.py
index 2a91ee35c675..21a32cff6580 100644
--- a/libraries/easy/samples/2_key_value/tests/conftest.py
+++ b/libraries/easy/samples/2_key_value/tests/conftest.py
@@ -9,10 +9,15 @@
 
 
 @pytest.fixture(scope="session")
-def pgsql_local(service_tmpdir, service_binary, pgsql_local_create):
-    schema_path = service_tmpdir.joinpath("schemas")
-    os.mkdir(schema_path)
-    subprocess.run([service_binary, "--dump-schema", schema_path])
+def schema_path(service_binary, service_tmpdir):
+    path = service_tmpdir.joinpath("schemas")
+    os.mkdir(path)
+    subprocess.run([service_binary, "--dump-db-schema", path / "0_pg.sql"])
+    return path
+
+
+@pytest.fixture(scope="session")
+def pgsql_local(schema_path, pgsql_local_create):
     databases = discover.find_schemas("admin", [schema_path])
     return pgsql_local_create(list(databases.values()))
     # /// [psql prepare]
diff --git a/libraries/easy/samples/3_json/main.cpp b/libraries/easy/samples/3_json/main.cpp
index e93be32d3ad8..155fe88d97cf 100644
--- a/libraries/easy/samples/3_json/main.cpp
+++ b/libraries/easy/samples/3_json/main.cpp
@@ -13,7 +13,7 @@ CREATE TABLE IF NOT EXISTS key_value_table (
 
 int main(int argc, char* argv[]) {
     easy::HttpWith<easy::PgDep>(argc, argv)
-        .Schema(kSchema)
+        .DbSchema(kSchema)
         .Get(
             "/kv",
             [](formats::json::Value request_json, const easy::PgDep& dep) {
@@ -28,7 +28,7 @@ int main(int argc, char* argv[]) {
                 return formats::json::ValueBuilder{response}.ExtractValue();
             }
         )
-        .Post("/kv", [](formats::json::Value request_json, const auto& dep) {
+        .Post("/kv", [](formats::json::Value request_json, easy::PgDep dep) {
             // Use generated parser for As()
             auto key_value = request_json.As<schemas::KeyValue>();
 
diff --git a/libraries/easy/samples/3_json/tests/conftest.py b/libraries/easy/samples/3_json/tests/conftest.py
index 2a91ee35c675..c927a72c0ffe 100644
--- a/libraries/easy/samples/3_json/tests/conftest.py
+++ b/libraries/easy/samples/3_json/tests/conftest.py
@@ -1,4 +1,4 @@
-# /// [psql prepare]
+# /// [pgsql prepare]
 import os
 import pytest
 import subprocess
@@ -9,10 +9,15 @@
 
 
 @pytest.fixture(scope="session")
-def pgsql_local(service_tmpdir, service_binary, pgsql_local_create):
-    schema_path = service_tmpdir.joinpath("schemas")
-    os.mkdir(schema_path)
-    subprocess.run([service_binary, "--dump-schema", schema_path])
+def schema_path(service_binary, service_tmpdir):
+    path = service_tmpdir.joinpath("schemas")
+    os.mkdir(path)
+    subprocess.run([service_binary, "--dump-db-schema", path / "0_pg.sql"])
+    return path
+
+
+@pytest.fixture(scope="session")
+def pgsql_local(schema_path, pgsql_local_create):
     databases = discover.find_schemas("admin", [schema_path])
     return pgsql_local_create(list(databases.values()))
-    # /// [psql prepare]
+    # /// [pgsql prepare]
diff --git a/libraries/easy/samples/4_custom_dependency/main.cpp b/libraries/easy/samples/4_custom_dependency/main.cpp
index bd719fe5be4d..70c4a8c64bb3 100644
--- a/libraries/easy/samples/4_custom_dependency/main.cpp
+++ b/libraries/easy/samples/4_custom_dependency/main.cpp
@@ -4,61 +4,72 @@
 #include <userver/easy.hpp>
 #include <userver/yaml_config/merge_schemas.hpp>
 
+#include <userver/clients/http/component.hpp>
+#include <userver/components/component_context.hpp>
+
 constexpr std::string_view kSchema = R"~(
 CREATE TABLE IF NOT EXISTS events_table (
   id serial NOT NULL,
-	action VARCHAR PRIMARY KEY,
-	host_id INTEGER
+	action VARCHAR PRIMARY KEY
 )
 )~";
 
-class MyDependency : public easy::PgDep {
+class ActionClient : public components::ComponentBase {
 public:
-    MyDependency(const components::ComponentConfig& config, const components::ComponentContext& context)
-        : PgDep(config, context), host_id_(config["host_id"].As<int>()) {}
+    static constexpr std::string_view kName = "action-client";
+
+    ActionClient(const components::ComponentConfig& config, const components::ComponentContext& context)
+        : ComponentBase{config, context},
+          service_url_(config["service-url"].As<std::string>()),
+          http_client_(context.FindComponent<components::HttpClient>().GetHttpClient()) {}
 
-    int host_id() const { return host_id_; }
+    auto CreateHttpRequest(std::string action) const {
+        return http_client_.CreateRequest().url(service_url_).post().data(std::move(action)).perform();
+    }
 
     static yaml_config::Schema GetStaticConfigSchema() {
-        return yaml_config::MergeSchemas<easy::PgDep>(R"(
+        return yaml_config::MergeSchemas<components::ComponentBase>(R"(
     type: object
-    description: ID of the host
+    description: My dependencies schema
     additionalProperties: false
     properties:
-        host_id:
-            type: integer
-            description: ID of the host
+        service-url:
+            type: string
+            description: URL of the service to send the actions to
     )");
     }
 
 private:
-    const int host_id_;
+    const std::string service_url_;
+    clients::http::Client& http_client_;
 };
 
-void Registration(easy::OfDependency<MyDependency>, easy::HttpBase& app) {
-    Registration(easy::OfDependency<easy::PgDep>{}, app);  // base class initilization
+class ActionDep {
+public:
+    explicit ActionDep(const components::ComponentContext& config) : component_{config.FindComponent<ActionClient>()} {}
+    auto CreateActionRequest(std::string action) const { return component_.CreateHttpRequest(std::move(action)); }
 
-    app.AddComponentsConfig(R"~(
-easy-dependencies:
-    host_id#env: HOST_ID
-    host_id#fallback: 42
-)~");
-}
+protected:
+    static void RegisterOn(easy::HttpBase& app) {
+        app.TryAddComponent<ActionClient>(ActionClient::kName, "service-url: http://some-service.example/v1/action");
+        easy::HttpDep::RegisterOn(app);
+    }
 
-template <>
-inline constexpr auto components::kConfigFileMode<MyDependency> = ConfigFileMode::kNotRequired;
+private:
+    ActionClient& component_;
+};
 
 int main(int argc, char* argv[]) {
-    easy::HttpWith<MyDependency>(argc, argv)
-        .Schema(kSchema)
+    using Deps = easy::Dependencies<ActionDep, easy::PgDep>;
+
+    easy::HttpWith<Deps>(argc, argv)
+        .DbSchema(kSchema)
         .DefaultContentType(http::content_type::kTextPlain)
-        .Post("/log", [](const server::http::HttpRequest& req, const MyDependency& dep) {
-            dep.pg().Execute(
-                storages::postgres::ClusterHostType::kMaster,
-                "INSERT INTO events_table(action, host_id) VALUES($1, $2)",
-                req.GetArg("action"),
-                dep.host_id()
+        .Post("/log", [](const server::http::HttpRequest& req, const Deps& deps) {
+            const auto& action = req.GetArg("action");
+            deps.pg().Execute(
+                storages::postgres::ClusterHostType::kMaster, "INSERT INTO events_table(action) VALUES($1)", action
             );
-            return std::string{};
+            return deps.CreateActionRequest(action)->body();
         });
 }
diff --git a/libraries/easy/samples/4_custom_dependency/tests/conftest.py b/libraries/easy/samples/4_custom_dependency/tests/conftest.py
index 2a91ee35c675..31c20c170a3c 100644
--- a/libraries/easy/samples/4_custom_dependency/tests/conftest.py
+++ b/libraries/easy/samples/4_custom_dependency/tests/conftest.py
@@ -1,4 +1,4 @@
-# /// [psql prepare]
+# /// [pgsql prepare]
 import os
 import pytest
 import subprocess
@@ -7,12 +7,28 @@
 
 pytest_plugins = ["pytest_userver.plugins.postgresql"]
 
+USERVER_CONFIG_HOOKS = ["userver_actions_service"]
+
+
+@pytest.fixture(scope="session")
+def userver_actions_service(mockserver_info):
+    def do_patch(config_yaml, config_vars):
+        components = config_yaml["components_manager"]["components"]
+        components["action-client"]["service-url"] = mockserver_info.url("/v1/action")
+
+    return do_patch
+
+
+@pytest.fixture(scope="session")
+def schema_path(service_binary, service_tmpdir):
+    path = service_tmpdir.joinpath("schemas")
+    os.mkdir(path)
+    subprocess.run([service_binary, "--dump-db-schema", path / "0_pg.sql"])
+    return path
+
 
 @pytest.fixture(scope="session")
-def pgsql_local(service_tmpdir, service_binary, pgsql_local_create):
-    schema_path = service_tmpdir.joinpath("schemas")
-    os.mkdir(schema_path)
-    subprocess.run([service_binary, "--dump-schema", schema_path])
+def pgsql_local(schema_path, pgsql_local_create):
     databases = discover.find_schemas("admin", [schema_path])
     return pgsql_local_create(list(databases.values()))
-    # /// [psql prepare]
+    # /// [pgsql prepare]
diff --git a/libraries/easy/samples/4_custom_dependency/tests/test_basic.py b/libraries/easy/samples/4_custom_dependency/tests/test_basic.py
index 25735a7b0f67..6e599154d046 100644
--- a/libraries/easy/samples/4_custom_dependency/tests/test_basic.py
+++ b/libraries/easy/samples/4_custom_dependency/tests/test_basic.py
@@ -1,10 +1,14 @@
-async def test_log_action(service_client, pgsql):
+async def test_log_action(service_client, pgsql, mockserver):
+    @mockserver.handler("/v1/action")
+    def _mock(request):
+        assert request.get_data() == b"test_1", f"Actual data is {request.get_data()}"
+        return mockserver.make_response()
+
     response = await service_client.post("/log?action=test_1")
     assert response.status == 200
 
     cursor = pgsql["0_pg"].cursor()  # '0_pg.sql' is created by easy::PgDep, so the database is '0_pg'
-    cursor.execute("SELECT action, host_id FROM events_table WHERE id=1")
+    cursor.execute("SELECT action FROM events_table WHERE id=1")
     result = cursor.fetchall()
     assert len(result) == 1
     assert result[0][0] == "test_1"
-    assert result[0][1] == 42
diff --git a/libraries/easy/src/easy.cpp b/libraries/easy/src/easy.cpp
index 17ecca90e4fc..1f61bdf1fa51 100644
--- a/libraries/easy/src/easy.cpp
+++ b/libraries/easy/src/easy.cpp
@@ -8,6 +8,7 @@
 #include <boost/program_options.hpp>
 
 #include <userver/clients/dns/component.hpp>
+#include <userver/clients/http/component.hpp>
 #include <userver/components/component_context.hpp>
 #include <userver/components/minimal_server_component_list.hpp>
 #include <userver/components/run.hpp>
@@ -33,52 +34,51 @@ constexpr std::string_view kConfigBase = R"~(
 
     default_task_processor: main-task-processor  # Task processor in which components start.
 
-    components:                       # Configuring components that were registered via component_list
-)~";
+    components:                       # Configuring components that were registered via component_list)~";
 
 constexpr std::string_view kConfigServerTemplate = R"~(
-server:
-    listener:                 # configuring the main listening socket...
-        port: {}            # ...to listen on this port and...
-        task_processor: main-task-processor    # ...process incoming requests on this task processor.
+        server:
+            listener:                 # configuring the main listening socket...
+                port: {}            # ...to listen on this port and...
+                task_processor: main-task-processor    # ...process incoming requests on this task processor.
 )~";
 
 constexpr std::string_view kConfigLoggingTemplate = R"~(
-logging:
-    fs-task-processor: fs-task-processor
-    loggers:
-        default:
-            file_path: '@stderr'
-            level: {}
-            overflow_behavior: discard  # Drop logs if the system is too busy to write them down.
+        logging:
+            fs-task-processor: fs-task-processor
+            loggers:
+                default:
+                    file_path: '@stderr'
+                    level: {}
+                    overflow_behavior: discard  # Drop logs if the system is too busy to write them down.
 )~";
 
-constexpr std::string_view kConfigHandlerTemplate = R"~(
-{0}:
-    path: {1}                  # Registering handler by URL '{1}'.
-    method: {2}
-    task_processor: main-task-processor  # Run it on CPU bound task processor
-)~";
+constexpr std::string_view kConfigHandlerTemplate{
+    "path: {0}                  # Registering handler by URL '{0}'.\n"
+    "method: {1}\n"
+    "task_processor: main-task-processor  # Run it on CPU bound task processor\n"};
 
 struct SharedPyaload {
     std::unordered_map<std::string, HttpBase::Callback> http_functions;
     std::optional<http::ContentType> default_content_type;
-    std::string schema;
+    std::string db_schema;
 };
 
 SharedPyaload globals{};
 
 }  // anonymous namespace
 
+namespace impl {
+
 DependenciesBase::~DependenciesBase() = default;
 
-const std::string& DependenciesBase::GetSchema() noexcept { return globals.schema; }
+}  // namespace impl
 
 class HttpBase::Handle final : public server::handlers::HttpHandlerBase {
 public:
     Handle(const components::ComponentConfig& config, const components::ComponentContext& context)
         : HttpHandlerBase(config, context),
-          deps_{context.FindComponent<DependenciesBase>()},
+          deps_{context.FindComponent<impl::DependenciesBase>()},
           callback_{globals.http_functions.at(config.Name())} {}
 
     std::string HandleRequestThrow(const server::http::HttpRequest& request, server::request::RequestContext&)
@@ -90,7 +90,7 @@ class HttpBase::Handle final : public server::handlers::HttpHandlerBase {
     }
 
 private:
-    const DependenciesBase& deps_;
+    const impl::DependenciesBase& deps_;
     HttpBase::Callback& callback_;
 };
 
@@ -101,8 +101,8 @@ HttpBase::HttpBase(int argc, const char* const argv[])
       component_list_{components::MinimalServerComponentList()} {}
 
 HttpBase::~HttpBase() {
-    AddComponentsConfig(fmt::format(kConfigServerTemplate, port_));
-    AddComponentsConfig(fmt::format(kConfigLoggingTemplate, ToString(level_)));
+    static_config_.append(fmt::format(kConfigServerTemplate, port_));
+    static_config_.append(fmt::format(kConfigLoggingTemplate, ToString(level_)));
 
     namespace po = boost::program_options;
     po::variables_map vm;
@@ -113,7 +113,7 @@ HttpBase::~HttpBase() {
     // clang-format off
     desc.add_options()
       ("dump-config", po::value(&config_dump), "path to dump the server config")
-      ("dump-schema", po::value(&schema_dump), "path to dump the DB schema")
+      ("dump-db-schema", po::value(&schema_dump), "path to dump the DB schema")
       ("config,c", po::value<std::string>(), "path to server config")
     ;
     // clang-format on
@@ -131,8 +131,8 @@ HttpBase::~HttpBase() {
         return;
     }
 
-    if (vm.count("dump-schema")) {
-        std::ofstream(schema_dump + "/0_pg.sql") << globals.schema;
+    if (vm.count("dump-db-schema")) {
+        std::ofstream(schema_dump) << globals.db_schema;
     }
 
     if (argc_ <= 1) {
@@ -152,43 +152,61 @@ void HttpBase::Route(std::string_view path, Callback&& func, std::initializer_li
 
     globals.http_functions.emplace(component_name, std::move(func));
     component_list_.Append<Handle>(component_name);
-    AddComponentsConfig(fmt::format(kConfigHandlerTemplate, component_name, path, fmt::join(methods, ",")));
+    AddComponentConfig(component_name, fmt::format(kConfigHandlerTemplate, path, fmt::join(methods, ",")));
 }
 
-void HttpBase::AddComponentsConfig(std::string_view config) {
-    auto conf = fmt::format("\n{}\n", config);
-    static_config_ += boost::algorithm::replace_all_copy(conf, "\n", "\n        ");
+void HttpBase::AddComponentConfig(std::string_view component, std::string_view config) {
+    static_config_ += fmt::format("\n        {}:", component);
+    if (config.empty()) {
+        static_config_ += " {}\n";
+    } else {
+        if (config.back() == '\n') {
+            config = std::string_view{config.data(), config.size() - 1};
+        }
+        static_config_ += boost::algorithm::replace_all_copy("\n" + std::string{config}, "\n", "\n            ");
+        static_config_ += '\n';
+    }
 }
 
-void HttpBase::Schema(std::string_view schema) { globals.schema = schema; }
+void HttpBase::DbSchema(std::string_view schema) { globals.db_schema = schema; }
+
+const std::string& HttpBase::GetDbSchema() noexcept { return globals.db_schema; }
 
 void HttpBase::Port(std::uint16_t port) { port_ = port; }
 
 void HttpBase::LogLevel(logging::Level level) { level_ = level; }
 
-PgDep::PgDep(const components::ComponentConfig& config, const components::ComponentContext& context)
-    : DependenciesBase{config, context},
-      pg_cluster_(context.FindComponent<components::Postgres>("postgres").GetCluster()) {
-    pg_cluster_->Execute(storages::postgres::ClusterHostType::kMaster, GetSchema());
+PgDep::PgDep(const components::ComponentContext& context)
+    : pg_cluster_(context.FindComponent<components::Postgres>("postgres").GetCluster()) {
+    pg_cluster_->Execute(storages::postgres::ClusterHostType::kMaster, HttpBase::GetDbSchema());
 }
 
-void Registration(OfDependency<PgDep>, HttpBase& app) {
-    app.AddComponentsConfig(R"~(
-postgres:
-    dbconnection#env: POSTGRESQL
-    dbconnection#fallback: 'postgresql://testsuite@localhost:15433/postgres'
-    blocking_task_processor: fs-task-processor
-    dns_resolver: async
-
-testsuite-support:
-
-dns-client:
-    fs-task-processor: fs-task-processor
-)~");
+void PgDep::RegisterOn(HttpBase& app) {
+    app.TryAddComponent<components::Postgres>(
+        "postgres",
+        "dbconnection#env: POSTGRESQL\n"
+        "dbconnection#fallback: 'postgresql://testsuite@localhost:15433/postgres'\n"
+        "blocking_task_processor: fs-task-processor\n"
+        "dns_resolver: async\n"
+    );
+
+    app.TryAddComponent<components::TestsuiteSupport>(components::TestsuiteSupport::kName, "");
+    app.TryAddComponent<clients::dns::Component>(
+        clients::dns::Component::kName, "fs-task-processor: fs-task-processor"
+    );
+}
 
-    app.AppendComponent<components::Postgres>("postgres");
-    app.AppendComponent<components::TestsuiteSupport>();
-    app.AppendComponent<clients::dns::Component>();
+HttpDep::HttpDep(const components::ComponentContext& context)
+    : http_(context.FindComponent<components::HttpClient>().GetHttpClient()) {}
+
+void HttpDep::RegisterOn(easy::HttpBase& app) {
+    app.TryAddComponent<components::HttpClient>(
+        components::HttpClient::kName,
+        "pool-statistics-disable: false\n"
+        "thread-name-prefix: http-client\n"
+        "threads: 2\n"
+        "fs-task-processor: fs-task-processor\n"
+    );
 }
 
 }  // namespace easy

From 564d49a200e743d2a563d6ae6432b141e84d32a1 Mon Sep 17 00:00:00 2001
From: Antony Polukhin <antoshkka@gmail.com>
Date: Sun, 1 Dec 2024 17:32:36 +0300
Subject: [PATCH 19/19] minimal docs

---
 scripts/docs/en/userver/libraries/easy.md | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/scripts/docs/en/userver/libraries/easy.md b/scripts/docs/en/userver/libraries/easy.md
index d623532a1626..39e2f2104ab8 100644
--- a/scripts/docs/en/userver/libraries/easy.md
+++ b/scripts/docs/en/userver/libraries/easy.md
@@ -1,3 +1,11 @@
 ## Easy - library for single file prototyping
 
-TODO:
+**Quality:** @ref QUALITY_TIERS "Silver Tier".
+
+Library for easy prototyping. Service functionality is described in code in a
+short and declarative way. Static configs and database schemas are applied
+automatically.
+
+Migration of a service on easy library to a more functional
+[pg_service_template](https://github.com/userver-framework/pg_service_template)
+is straightforward.