From 23c2c9d516884fcc569cc0ad451214e6eff1fc09 Mon Sep 17 00:00:00 2001
From: Matt Sicker <msicker@apple.com>
Date: Thu, 7 Dec 2023 16:40:26 -0600
Subject: [PATCH] feat(web): Improve error handling for WebClient

This ensures that errors in WebClient are treated similarly to Retrofit.
---
 .../exceptions/GenericExceptionHandlers.java  | 35 ++++++++++++++++++
 .../web/exceptions/UpstreamRequestError.java  | 36 +++++++++++++++++++
 2 files changed, 71 insertions(+)
 create mode 100644 kork-web/src/main/java/com/netflix/spinnaker/kork/web/exceptions/UpstreamRequestError.java

diff --git a/kork-web/src/main/java/com/netflix/spinnaker/kork/web/exceptions/GenericExceptionHandlers.java b/kork-web/src/main/java/com/netflix/spinnaker/kork/web/exceptions/GenericExceptionHandlers.java
index 1f9a0cefa..8513840cc 100644
--- a/kork-web/src/main/java/com/netflix/spinnaker/kork/web/exceptions/GenericExceptionHandlers.java
+++ b/kork-web/src/main/java/com/netflix/spinnaker/kork/web/exceptions/GenericExceptionHandlers.java
@@ -30,11 +30,16 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.core.annotation.AnnotationUtils;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpRequest;
 import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
 import org.springframework.security.access.AccessDeniedException;
 import org.springframework.web.bind.annotation.ControllerAdvice;
 import org.springframework.web.bind.annotation.ExceptionHandler;
 import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.web.reactive.function.client.WebClientResponseException;
 import retrofit.RetrofitError;
 import retrofit.client.Header;
 
@@ -89,6 +94,36 @@ public void handleIllegalStateException(
     handleResponseStatusAnnotatedException(e, response);
   }
 
+  @ExceptionHandler(WebClientResponseException.class)
+  public ResponseEntity<UpstreamRequestError> handleWebClientResponseException(
+      WebClientResponseException e) {
+    HttpStatus statusCode = e.getStatusCode();
+    var builder = ResponseEntity.status(statusCode);
+    var error = new UpstreamRequestError();
+    error.setStatus(e.getRawStatusCode());
+    error.setError(e.getStatusText());
+    HttpRequest request = e.getRequest();
+    if (request != null) {
+      error.setUri(request.getURI());
+      error.setMethod(request.getMethod());
+    }
+    HttpHeaders headers = e.getHeaders();
+    String eTag = headers.getETag();
+    if (eTag != null) {
+      builder.eTag(eTag);
+    }
+    long lastModified = headers.getLastModified();
+    if (lastModified != -1) {
+      builder.lastModified(lastModified);
+    }
+    MediaType contentType = headers.getContentType();
+    if (contentType != null && contentType.isCompatibleWith(MediaType.APPLICATION_JSON)) {
+      error.setBody(e.getResponseBodyAsString());
+    }
+    error.setMessage(exceptionMessageDecorator.decorate(e, e.getMessage()));
+    return builder.body(error);
+  }
+
   @ExceptionHandler(RetrofitError.class)
   public void handleRetrofitError(
       RetrofitError e, HttpServletResponse response, HttpServletRequest request)
diff --git a/kork-web/src/main/java/com/netflix/spinnaker/kork/web/exceptions/UpstreamRequestError.java b/kork-web/src/main/java/com/netflix/spinnaker/kork/web/exceptions/UpstreamRequestError.java
new file mode 100644
index 000000000..4a37c4b3f
--- /dev/null
+++ b/kork-web/src/main/java/com/netflix/spinnaker/kork/web/exceptions/UpstreamRequestError.java
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2023 Apple Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.netflix.spinnaker.kork.web.exceptions;
+
+import com.fasterxml.jackson.annotation.JsonRawValue;
+import java.net.URI;
+import java.time.Instant;
+import lombok.Getter;
+import lombok.Setter;
+import org.springframework.http.HttpMethod;
+
+@Getter
+@Setter
+public class UpstreamRequestError {
+  private int status;
+  private String error;
+  private Instant timestamp = Instant.now();
+  private HttpMethod method;
+  private URI uri;
+  private String message;
+  @JsonRawValue private String body;
+}