validator: added a validator crate

fixes informalsystems#1134

.changelog/unreleased/features/1134-validator-crate.md

@@ -0,0 +1,2 @@
+- Added validator crate as per ADR-011
+  ([#1134](https://github.com/informalsystems/tendermint-rs/issues/1134))

Cargo.toml

@@ -13,7 +13,8 @@ members = [
     "std-ext",
     "tendermint",
     "test",
-    "testgen"
+    "testgen",
+    "validator"
 ]
 
 exclude = [

validator/Cargo.toml

@@ -0,0 +1,35 @@
+[package]
+name        = "tendermint-validator"
+version     = "0.24.0-pre.2"
+authors     = ["Informal Systems <[email protected]>"]
+edition     = "2021"
+license     = "Apache-2.0"
+readme      = "README.md"
+categories  = ["cryptography::cryptocurrencies", "network-programming"]
+keywords    = ["privval", "validator", "blockchain", "bft", "consensus", "tendermint"]
+repository  = "https://github.com/informalsystems/tendermint-rs"
+description = """
+    tendermint-validator provides a simple framework with which to build key management
+    for Tendermint validators.
+    """
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[features]
+default = ["flex-error/std", "flex-error/eyre_tracer"]
+
+[dependencies]
+ed25519-consensus = { version = "1.2", default-features = false }
+flex-error = { version = "0.4.4", default-features = false }
+rand_core = { version = "0.6", default-features = false, features = ["std"] }
+serde_json = "1"
+tempfile = { version = "3.2.0" }
+tendermint = { version = "0.24.0-pre.2", default-features = false, path = "../tendermint" }
+tendermint-proto = { version = "0.24.0-pre.2", default-features = false, path = "../proto", features = ["grpc"] }
+tokio = { version = "1", features = ["full"] }
+tokio-stream = { version = "0.1", features = ["net"] }
+tonic = { version = "0.7", features = ["tls", "transport"] }
+tracing = { version = "0.1", default-features = false }
+
+[dev-dependencies]
+tracing-subscriber = "0.2"

validator/examples/softsign.rs

@@ -0,0 +1,36 @@
+// use std::collections::HashMap;
+
+// use ed25519_consensus::SigningKey;
+// use tendermint::account::Id;
+// use tendermint_validator::{
+//     BasicServerConfig, FileStateProvider, GrpcSocket, SoftwareSigner, SoftwareSignerServer,
+// };
+
+use std::collections::HashMap;
+
+use tendermint::chain;
+use tendermint_validator::{
+    BasicServerConfig, FileStateProvider, GrpcSocket, KMSServer, SoftwareSigner,
+};
+use tracing::Level;
+use tracing_subscriber::FmtSubscriber;
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let subscriber = FmtSubscriber::builder()
+        .with_max_level(Level::INFO)
+        .finish();
+    let _ = tracing::subscriber::set_global_default(subscriber);
+    let mut providers = HashMap::new();
+    let signer = SoftwareSigner::generate_ed25519(rand_core::OsRng);
+    let state_provider = FileStateProvider::new("/tmp/validator.json".into())
+        .await
+        .unwrap();
+    providers.insert(
+        chain::Id::try_from("test-chain-4bmabt").unwrap(),
+        (signer, state_provider),
+    );
+    let config = BasicServerConfig::new(None, GrpcSocket::Unix("/tmp/validator.test".into()));
+    let server = KMSServer::new(providers, config).await.unwrap();
+    server.serve().await
+}

validator/src/config.rs

@@ -0,0 +1,30 @@
+//! Validator configuration.
+
+use std::{net::SocketAddr, path::PathBuf};
+
+use tonic::transport::ServerTlsConfig;
+
+/// The common options for listening for gRPC connections.
+#[derive(Debug, Clone)]
+pub enum GrpcSocket {
+    /// the syntax in Tendermint config is "grpc://HOST:PORT"
+    Tcp(SocketAddr),
+    /// the syntax in Tendermint config is "grpc://unix:PATH"
+    Unix(PathBuf),
+}
+
+/// The basic configuration for the gRPC server.
+#[derive(Debug, Clone)]
+pub struct BasicServerConfig {
+    /// The optional TLS configuration.
+    pub tls_config: Option<ServerTlsConfig>,
+    /// The choice of a socket type to listen on.
+    pub socket: GrpcSocket,
+}
+
+impl BasicServerConfig {
+    /// creates a basic config for the gRPC server
+    pub fn new(tls_config: Option<ServerTlsConfig>, socket: GrpcSocket) -> Self {
+        Self { tls_config, socket }
+    }
+}

validator/src/error.rs

@@ -0,0 +1,18 @@
+//! Validator errors (returned in a status via gRPC)
+
+use flex_error::{define_error, DetailOnly};
+
+define_error! {
+    Error {
+        IoError{
+            path: String,
+        } [DetailOnly<std::io::Error>] |e| {
+            format_args!("Error persisting {}", e.path)
+        },
+        JsonError{
+            path_or_msg: String,
+        } [DetailOnly<serde_json::Error>] |e| {
+            format_args!("Error parsing or serializing validator state {}", e.path_or_msg)
+        },
+    }
+}

validator/src/lib.rs

@@ -0,0 +1,13 @@
+//! A framework for building key management solutions for [Tendermint] validators in Rust.
+//!
+//! [Tendermint]: https://tendermint.com
+pub mod config;
+pub mod error;
+pub mod server;
+pub mod signer;
+pub mod state;
+
+pub use config::{BasicServerConfig, GrpcSocket};
+pub use server::KMSServer;
+pub use signer::{SignerProvider, SoftwareSigner};
+pub use state::{FileStateProvider, ValidatorStateProvider};