Expose system health via RPC and REST (#1269)

* Implement health endpoint.

* Expose health API.

substrate/core/service/src/components.rs

@@ -19,17 +19,17 @@
 use std::{sync::Arc, net::SocketAddr, marker::PhantomData, ops::Deref, ops::DerefMut};
 use serde::{Serialize, de::DeserializeOwned};
 use tokio::runtime::TaskExecutor;
-use chain_spec::{ChainSpec, Properties};
+use chain_spec::ChainSpec;
 use client_db;
 use client::{self, Client, runtime_api::{Metadata, TaggedTransactionQueue}};
-use {error, Service, RpcConfig, maybe_start_server};
+use {error, Service, maybe_start_server};
 use network::{self, OnDemand, import_queue::ImportQueue};
 use substrate_executor::{NativeExecutor, NativeExecutionDispatch};
 use transaction_pool::txpool::{self, Options as TransactionPoolOptions, Pool as TransactionPool};
 use runtime_primitives::{BuildStorage, traits::{Block as BlockT, Header as HeaderT, ProvideRuntimeApi}, generic::{BlockId, SignedBlock}};
 use config::Configuration;
 use primitives::{Blake2Hasher, H256};
-use rpc;
+use rpc::{self, apis::system::SystemInfo};
 use parking_lot::Mutex;
 
 // Type aliases.
@@ -123,12 +123,11 @@ pub trait StartRPC<C: Components> {
 
 	fn start_rpc(
 		client: Arc<ComponentClient<C>>,
-		chain_name: String,
-		impl_name: &'static str,
-		impl_version: &'static str,
+		network: Arc<network::SyncProvider<ComponentBlock<C>>>,
+		should_have_peers: bool,
+		system_info: SystemInfo,
 		rpc_http: Option<SocketAddr>,
 		rpc_ws: Option<SocketAddr>,
-		properties: Properties,
 		task_executor: TaskExecutor,
 		transaction_pool: Arc<TransactionPool<C::TransactionPoolApi>>,
 	) -> error::Result<Self::ServersHandle>;
@@ -142,17 +141,14 @@ impl<C: Components> StartRPC<Self> for C where
 
 	fn start_rpc(
 		client: Arc<ComponentClient<C>>,
-		chain_name: String,
-		impl_name: &'static str,
-		impl_version: &'static str,
+		network: Arc<network::SyncProvider<ComponentBlock<C>>>,
+		should_have_peers: bool,
+		rpc_system_info: SystemInfo,
 		rpc_http: Option<SocketAddr>,
 		rpc_ws: Option<SocketAddr>,
-		properties: Properties,
 		task_executor: TaskExecutor,
 		transaction_pool: Arc<TransactionPool<C::TransactionPoolApi>>,
 	) -> error::Result<Self::ServersHandle> {
-		let rpc_config = RpcConfig { properties, chain_name, impl_name, impl_version };
-
 		let handler = || {
 			let client = client.clone();
 			let subscriptions = rpc::apis::Subscriptions::new(task_executor.clone());
@@ -161,11 +157,14 @@ impl<C: Components> StartRPC<Self> for C where
 			let author = rpc::apis::author::Author::new(
 				client.clone(), transaction_pool.clone(), subscriptions
 			);
+			let system = rpc::apis::system::System::new(
+				rpc_system_info.clone(), network.clone(), should_have_peers
+			);
 			rpc::rpc_handler::<ComponentBlock<C>, ComponentExHash<C>, _, _, _, _>(
 				state,
 				chain,
 				author,
-				rpc_config.clone(),
+				system,
 			)
 		};
 

substrate/core/service/src/lib.rs

@@ -34,7 +34,6 @@ extern crate substrate_client as client;
 extern crate substrate_client_db as client_db;
 extern crate parity_codec as codec;
 extern crate substrate_transaction_pool as transaction_pool;
-extern crate substrate_rpc;
 extern crate substrate_rpc_servers as rpc;
 extern crate target_info;
 extern crate tokio;
@@ -189,6 +188,7 @@ impl<Components: components::Components> Service<Components> {
 			protocol_id
 		};
 
+		let has_bootnodes = !network_params.network_config.boot_nodes.is_empty();
 		let network = network::Service::new(
 			network_params,
 			protocol_id,
@@ -240,10 +240,14 @@ impl<Components: components::Components> Service<Components> {
 
 
 		// RPC
+		let system_info = rpc::apis::system::SystemInfo {
+			chain_name: config.chain_spec.name().into(),
+			impl_name: config.impl_name.into(),
+			impl_version: config.impl_version.into(),
+			properties: config.chain_spec.properties(),
+		};
 		let rpc = Components::RPC::start_rpc(
-			client.clone(), config.chain_spec.name().to_string(), config.impl_name,
-			config.impl_version, config.rpc_http, config.rpc_ws, config.chain_spec.properties(),
-			task_executor.clone(), transaction_pool.clone()
+			client.clone(), network.clone(), has_bootnodes, system_info, config.rpc_http, config.rpc_ws, task_executor.clone(), transaction_pool.clone(),
 		)?;
 
 		// Telemetry
@@ -358,32 +362,6 @@ fn maybe_start_server<T, F>(address: Option<SocketAddr>, start: F) -> Result<Opt
 	})
 }
 
-#[derive(Clone)]
-struct RpcConfig {
-	chain_name: String,
-	properties: Properties,
-	impl_name: &'static str,
-	impl_version: &'static str,
-}
-
-impl substrate_rpc::system::SystemApi for RpcConfig {
-	fn system_name(&self) -> substrate_rpc::system::error::Result<String> {
-		Ok(self.impl_name.into())
-	}
-
-	fn system_version(&self) -> substrate_rpc::system::error::Result<String> {
-		Ok(self.impl_version.into())
-	}
-
-	fn system_chain(&self) -> substrate_rpc::system::error::Result<String> {
-		Ok(self.chain_name.clone())
-	}
-
-	fn system_properties(&self) -> substrate_rpc::system::error::Result<Properties> {
-		Ok(self.properties.clone())
-	}
-}
-
 /// Transaction pool adapter.
 pub struct TransactionPoolAdapter<C: Components> {
 	imports_external_transactions: bool,