RPC call to get all RPC methods (#3613)

* Add meta rpc_methods call.

* Sort methods.

* Bump runtime.

* Change format a bit to support versioning.

substrate/core/rpc-servers/Cargo.toml

@@ -5,12 +5,13 @@ authors = ["Parity Technologies <admin@parity.io>"]
 edition = "2018"
 
 [dependencies]
-jsonrpc-core = "13.1.0"
-pubsub = { package = "jsonrpc-pubsub", version = "13.1.0" }
+jsonrpc-core = "13.2.0"
+pubsub = { package = "jsonrpc-pubsub", version = "13.2.0" }
 log = "0.4"
 serde = "1.0"
+serde_json = "1.0"
 sr-primitives = { path = "../sr-primitives" }
 
 [target.'cfg(not(target_os = "unknown"))'.dependencies]
-http = { package = "jsonrpc-http-server", version = "13.1.0" }
-ws = { package = "jsonrpc-ws-server", version = "13.1.0" }
+http = { package = "jsonrpc-http-server", version = "13.2.0" }
+ws = { package = "jsonrpc-ws-server", version = "13.2.0" }

substrate/core/rpc-servers/src/lib.rs

@@ -40,6 +40,19 @@ pub fn rpc_handler<M: PubSubMetadata>(
 ) -> RpcHandler<M> {
 	let mut io = pubsub::PubSubHandler::default();
 	extension.augment(&mut io);
+
+	// add an endpoint to list all available methods.
+	let mut methods = io.iter().map(|x| x.0.clone()).collect::<Vec<String>>();
+	io.add_method("rpc_methods", {
+		methods.sort();
+		let methods = serde_json::to_value(&methods)
+			.expect("Serialization of Vec<String> is infallible; qed");
+
+		move |_| Ok(serde_json::json!({
+			"version": 1,
+			"methods": methods.clone(),
+		}))
+	});
 	io
 }
 

substrate/core/rpc/api/Cargo.toml

@@ -8,10 +8,10 @@ edition = "2018"
 codec = { package = "parity-scale-codec", version = "1.0.0" }
 derive_more = "0.14.0"
 futures03 = { package = "futures-preview", version = "0.3.0-alpha.17", features = ["compat"] }
-jsonrpc-core = "13.0.0"
-jsonrpc-core-client = "13.0.0"
-jsonrpc-derive = "13.0.0"
-jsonrpc-pubsub = "13.0.0"
+jsonrpc-core = "13.2.0"
+jsonrpc-core-client = "13.2.0"
+jsonrpc-derive = "13.2.0"
+jsonrpc-pubsub = "13.2.0"
 log = "0.4"
 parking_lot = "0.9.0"
 primitives = { package = "substrate-primitives", path = "../../primitives" }

substrate/core/service/src/builder.rs

@@ -821,12 +821,9 @@ ServiceBuilder<
 			TBl
 		>,
 	>, Error> {
-		let mut config = self.config;
-		session::generate_initial_session_keys(
-			self.client.clone(),
-			config.dev_key_seed.clone().map(|s| vec![s]).unwrap_or_default()
-		)?;
-		let (
+		let ServiceBuilder {
+			marker: _,
+			mut config,
 			client,
 			fetcher,
 			backend,
@@ -840,21 +837,12 @@ ServiceBuilder<
 			rpc_extensions,
 			dht_event_tx,
 			rpc_builder,
-		) = (
-			self.client,
-			self.fetcher,
-			self.backend,
-			self.keystore,
-			self.select_chain,
-			self.import_queue,
-			self.finality_proof_request_builder,
-			self.finality_proof_provider,
-			self.network_protocol,
-			self.transaction_pool,
-			self.rpc_extensions,
-			self.dht_event_tx,
-			self.rpc_builder,
-		);
+		} = self;
+
+		session::generate_initial_session_keys(
+			client.clone(),
+			config.dev_key_seed.clone().map(|s| vec![s]).unwrap_or_default()
+		)?;
 
 		new_impl!(
 			TBl,