in auto-relays keep trying to connect to nodes until connection is established (#971)

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

@@ -27,6 +27,7 @@ use jsonrpsee_ws_client::{traits::SubscriptionClient, v2::params::JsonRpcParams,
 use jsonrpsee_ws_client::{Subscription, WsClient as RpcClient, WsClientBuilder as RpcClientBuilder};
 use num_traits::Zero;
 use pallet_balances::AccountData;
+use relay_utils::relay_loop::RECONNECT_DELAY;
 use sp_core::{storage::StorageKey, Bytes};
 use sp_trie::StorageProof;
 use sp_version::RuntimeVersion;
@@ -77,7 +78,29 @@ impl<C: Chain> std::fmt::Debug for Client<C> {
 
 impl<C: Chain> Client<C> {
 	/// Returns client that is able to call RPCs on Substrate node over websocket connection.
-	pub async fn new(params: ConnectionParams) -> Result<Self> {
+	///
+	/// This function will keep connecting to given Sustrate node until connection is established
+	/// and is functional. If attempt fail, it will wait for `RECONNECT_DELAY` and retry again.
+	pub async fn new(params: ConnectionParams) -> Self {
+		loop {
+			match Self::try_connect(params.clone()).await {
+				Ok(client) => return client,
+				Err(error) => log::error!(
+					target: "bridge",
+					"Failed to connect to {} node: {:?}. Going to retry in {}s",
+					C::NAME,
+					error,
+					RECONNECT_DELAY.as_secs(),
+				),
+			}
+
+			async_std::task::sleep(RECONNECT_DELAY).await;
+		}
+	}
+
+	/// Try to connect to Substrate node over websocket. Returns Substrate RPC client if connection
+	/// has been established or error otherwise.
+	pub async fn try_connect(params: ConnectionParams) -> Result<Self> {
 		let client = Self::build_client(params.clone()).await?;
 
 		let number: C::BlockNumber = Zero::zero();