Some relayer improvments (#2902)

* added CLI arguments: full WS URI + separate for WS path URI component + additional log

* URI -> URL?

* added TODO

* fmt

bridges/relays/client-substrate/src/client.rs

@@ -264,12 +264,22 @@ impl<C: Chain> Client<C> {
 		params: &ConnectionParams,
 	) -> Result<(Arc<tokio::runtime::Runtime>, Arc<RpcClient>)> {
 		let tokio = tokio::runtime::Runtime::new()?;
-		let uri = format!(
-			"{}://{}:{}",
-			if params.secure { "wss" } else { "ws" },
-			params.host,
-			params.port,
-		);
+
+		let uri = match params.uri {
+			Some(ref uri) => uri.clone(),
+			None => {
+				format!(
+					"{}://{}:{}{}",
+					if params.secure { "wss" } else { "ws" },
+					params.host,
+					params.port,
+					match params.path {
+						Some(ref path) => format!("/{}", path),
+						None => String::new(),
+					},
+				)
+			},
+		};
 		log::info!(target: "bridge", "Connecting to {} node at {}", C::NAME, uri);
 
 		let client = tokio

bridges/relays/client-substrate/src/lib.rs

@@ -57,10 +57,15 @@ pub use bp_runtime::{
 /// Substrate-over-websocket connection params.
 #[derive(Debug, Clone)]
 pub struct ConnectionParams {
+	/// Websocket endpoint URL. Overrides all other URL components (`host`, `port`, `path` and
+	/// `secure`).
+	pub uri: Option<String>,
 	/// Websocket server host name.
 	pub host: String,
 	/// Websocket server TCP port.
 	pub port: u16,
+	/// Websocket endpoint path at server.
+	pub path: Option<String>,
 	/// Use secure websocket connection.
 	pub secure: bool,
 	/// Defined chain runtime version
@@ -70,8 +75,10 @@ pub struct ConnectionParams {
 impl Default for ConnectionParams {
 	fn default() -> Self {
 		ConnectionParams {
+			uri: None,
 			host: "localhost".into(),
 			port: 9944,
+			path: None,
 			secure: false,
 			chain_runtime_version: ChainRuntimeVersion::Auto,
 		}