Simplify Service Discovery by decoupling the service registry from in…

…tent brokering (#141)

Service Discovery as its own service - Simple implementation

Cargo.toml

@@ -1,3 +1,7 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT license.
+# SPDX-License-Identifier: MIT
+
 [workspace]
 members = [
     "common",
@@ -15,10 +19,11 @@ members = [
     "examples/common",
     "keyvalue",
     "proto.rs",
+    "service_discovery/core",
+    "service_discovery/samples/simple-discovery/consumer",
+    "service_discovery/samples/simple-discovery/provider"
 ]
 
-exclude = []
-
 [package]
 name = "chariott"
 version = "0.1.0"
@@ -55,6 +60,7 @@ chariott-common = { path = "./common/" }
 chariott-proto = { path = "./proto.rs/" }
 futures = { version = "0.3" }
 lazy_static = "1.4.0"
+parking_lot = "0.12.1"
 prost = "0.11"
 prost-types = "0.11"
 regex = "1.7"

service_discovery/core/Cargo.toml

@@ -0,0 +1,21 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT license.
+# SPDX-License-Identifier: MIT
+
+[package]
+name = "service_discovery"
+version = "0.1.0"
+edition = "2021"
+license = "MIT"
+
+[dependencies]
+parking_lot = { workspace = true }
+prost = { workspace = true }
+service_discovery_proto = { path = "../proto_build/"}
+tokio = { workspace = true, features = ["macros", "rt-multi-thread"] }
+tonic = { workspace = true }
+tracing = { version = "0.1" }
+tracing-subscriber = { version = "0.3", features = ["env-filter"] }
+
+[build-dependencies]
+tonic-build = { workspace = true }

service_discovery/core/src/main.rs

@@ -0,0 +1,52 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+// SPDX-License-Identifier: MIT
+
+//! Project Eclipse Chariott Service Discovery
+//!
+//! This is the Service Discovery system for Chariott. It includes a service registry,
+//! which is a database of services that are currently registered. Other applications
+//! can find the metadata for registered services.
+
+// Tells cargo to warn if a doc comment is missing and should be provided.
+#![warn(missing_docs)]
+
+use parking_lot::RwLock;
+use service_discovery_proto::service_registry::v1::service_registry_server::ServiceRegistryServer;
+use std::collections::HashMap;
+use std::net::SocketAddr;
+use std::sync::Arc;
+use tonic::transport::Server;
+use tracing::{debug, info};
+use tracing_subscriber::util::SubscriberInitExt;
+use tracing_subscriber::EnvFilter;
+
+mod service_registry_impl;
+
+/// Endpoint for the service registry
+const SERVICE_REGISTRY_ADDR: &str = "0.0.0.0:50000";
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    // Set up tracing
+    let collector = tracing_subscriber::fmt()
+        .with_env_filter(
+            EnvFilter::builder()
+                .with_default_directive(tracing::Level::INFO.into())
+                .from_env_lossy(),
+        )
+        .finish();
+
+    collector.init();
+
+    // Start up registry service
+    let addr: SocketAddr = SERVICE_REGISTRY_ADDR.parse()?;
+    let registry_impl =
+        service_registry_impl::ServiceRegistryImpl::new(Arc::new(RwLock::new(HashMap::new())));
+    info!("Service Registry listening on {addr}");
+
+    Server::builder().add_service(ServiceRegistryServer::new(registry_impl)).serve(addr).await?;
+
+    debug!("The Service Registry has completed.");
+    Ok(())
+}