in auto-relays keep trying to connect to nodes until connection is es…

…tablished (paritytech#971)

bridges/relays/bin-ethereum/src/ethereum_deploy_contract.rs

@@ -60,8 +60,8 @@ pub async fn run(params: EthereumDeployContractParams) {
 	} = params;
 
 	let result = async move {
-		let eth_client = EthereumClient::new(eth_params).await.map_err(RpcError::Ethereum)?;
-		let sub_client = SubstrateClient::<Rialto>::new(sub_params).await.map_err(RpcError::Substrate)?;
+		let eth_client = EthereumClient::try_connect(eth_params).await.map_err(RpcError::Ethereum)?;
+		let sub_client = SubstrateClient::<Rialto>::try_connect(sub_params).await.map_err(RpcError::Substrate)?;
 
 		let (initial_header_id, initial_header) = prepare_initial_header(&sub_client, sub_initial_header).await?;
 		let initial_set_id = sub_initial_authorities_set_id.unwrap_or(0);

bridges/relays/bin-ethereum/src/ethereum_exchange.rs

@@ -335,8 +335,10 @@ async fn run_single_transaction_relay(params: EthereumExchangeParams, eth_tx_has
 		..
 	} = params;
 
-	let eth_client = EthereumClient::new(eth_params).await.map_err(RpcError::Ethereum)?;
-	let sub_client = SubstrateClient::<Rialto>::new(sub_params)
+	let eth_client = EthereumClient::try_connect(eth_params)
+		.await
+		.map_err(RpcError::Ethereum)?;
+	let sub_client = SubstrateClient::<Rialto>::try_connect(sub_params)
 		.await
 		.map_err(RpcError::Substrate)?;
 
@@ -363,12 +365,8 @@ async fn run_auto_transactions_relay_loop(
 		..
 	} = params;
 
-	let eth_client = EthereumClient::new(eth_params)
-		.await
-		.map_err(|err| format!("Error starting Ethereum client: {:?}", err))?;
-	let sub_client = SubstrateClient::<Rialto>::new(sub_params)
-		.await
-		.map_err(|err| format!("Error starting Substrate client: {:?}", err))?;
+	let eth_client = EthereumClient::new(eth_params).await;
+	let sub_client = SubstrateClient::<Rialto>::new(sub_params).await;
 
 	let eth_start_with_block_number = match eth_start_with_block_number {
 		Some(eth_start_with_block_number) => eth_start_with_block_number,

bridges/relays/bin-ethereum/src/ethereum_exchange_submit.rs

@@ -52,7 +52,7 @@ pub async fn run(params: EthereumExchangeSubmitParams) {
 	} = params;
 
 	let result: Result<_, String> = async move {
-		let eth_client = EthereumClient::new(eth_params)
+		let eth_client = EthereumClient::try_connect(eth_params)
 			.await
 			.map_err(|err| format!("error connecting to Ethereum node: {:?}", err))?;
 

bridges/relays/bin-ethereum/src/ethereum_sync_loop.rs

@@ -270,8 +270,8 @@ pub async fn run(params: EthereumSyncParams) -> Result<(), RpcError> {
 		instance,
 	} = params;
 
-	let eth_client = EthereumClient::new(eth_params).await?;
-	let sub_client = SubstrateClient::<Rialto>::new(sub_params).await?;
+	let eth_client = EthereumClient::new(eth_params).await;
+	let sub_client = SubstrateClient::<Rialto>::new(sub_params).await;
 
 	let sign_sub_transactions = match sync_params.target_tx_mode {
 		TargetTransactionMode::Signed | TargetTransactionMode::Backup => true,

bridges/relays/bin-ethereum/src/substrate_sync_loop.rs

@@ -177,8 +177,8 @@ pub async fn run(params: SubstrateSyncParams) -> Result<(), RpcError> {
 		metrics_params,
 	} = params;
 
-	let eth_client = EthereumClient::new(eth_params).await?;
-	let sub_client = SubstrateClient::<Rialto>::new(sub_params).await?;
+	let eth_client = EthereumClient::new(eth_params).await;
+	let sub_client = SubstrateClient::<Rialto>::new(sub_params).await;
 
 	let target = EthereumHeadersTarget::new(eth_client, eth_contract_address, eth_sign);
 	let source = SubstrateHeadersSource::new(sub_client);

bridges/relays/bin-substrate/src/cli/mod.rs

@@ -406,7 +406,7 @@ macro_rules! declare_chain_options {
 						port: self.[<$chain_prefix _port>],
 						secure: self.[<$chain_prefix _secure>],
 					})
-					.await?
+					.await
 					)
 				}
 			}

bridges/relays/client-ethereum/Cargo.toml

@@ -6,6 +6,7 @@ edition = "2018"
 license = "GPL-3.0-or-later WITH Classpath-exception-2.0"
 
 [dependencies]
+async-std = "1.6.5"
 bp-eth-poa = { path = "../../primitives/ethereum-poa" }
 codec = { package = "parity-scale-codec", version = "2.0.0" }
 headers-relay = { path = "../headers" }

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

@@ -22,6 +22,7 @@ use crate::types::{
 use crate::{ConnectionParams, Error, Result};
 
 use jsonrpsee_ws_client::{WsClient as RpcClient, WsClientBuilder as RpcClientBuilder};
+use relay_utils::relay_loop::RECONNECT_DELAY;
 use std::sync::Arc;
 
 /// Number of headers missing from the Ethereum node for us to consider node not synced.
@@ -36,7 +37,28 @@ pub struct Client {
 
 impl Client {
 	/// Create a new Ethereum RPC Client.
-	pub async fn new(params: ConnectionParams) -> Result<Self> {
+	///
+	/// This function will keep connecting to given Ethereum 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 Ethereum node: {:?}. Going to retry in {}s",
+					error,
+					RECONNECT_DELAY.as_secs(),
+				),
+			}
+
+			async_std::task::sleep(RECONNECT_DELAY).await;
+		}
+	}
+
+	/// Try to connect to Ethereum node. Returns Ethereum RPC client if connection has been established
+	/// or error otherwise.
+	pub async fn try_connect(params: ConnectionParams) -> Result<Self> {
 		Ok(Self {
 			client: Self::build_client(&params).await?,
 			params,

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();