CFE RPC Client optional genesis hash check for tests (#4041)

* refactor: optional genesis hash for tests

* chore: renamed new_ext -> new_inner

engine/src/dot/http_rpc.rs

@@ -21,6 +21,7 @@ use subxt::{
 };
 
 use anyhow::Result;
+use tracing::{error, warn};
 use utilities::{make_periodic_tick, redact_endpoint_secret::SecretUrl};
 
 use crate::constants::DOT_AVERAGE_BLOCK_TIME;
@@ -80,7 +81,10 @@ pub struct DotHttpRpcClient {
 }
 
 impl DotHttpRpcClient {
-	pub fn new(url: SecretUrl) -> Result<impl Future<Output = Self>> {
+	pub fn new(
+		url: SecretUrl,
+		expected_genesis_hash: Option<PolkadotHash>,
+	) -> Result<impl Future<Output = Self>> {
 		let polkadot_http_client = Arc::new(PolkadotHttpClient::new(&url)?);
 
 		Ok(async move {
@@ -94,9 +98,23 @@ impl DotHttpRpcClient {
 				match OnlineClient::<PolkadotConfig>::from_rpc_client(polkadot_http_client.clone())
 					.await
 				{
-					Ok(online_client) => break online_client,
+					Ok(online_client) => {
+						if let Some(expected_genesis_hash) = expected_genesis_hash {
+							let genesis_hash = online_client.genesis_hash();
+							if genesis_hash == expected_genesis_hash {
+								break online_client
+							} else {
+								error!(
+									"Connected to Polkadot node at {url} but the genesis hash {genesis_hash} does not match the expected genesis hash {expected_genesis_hash}. Please check your CFE configuration file."
+								)
+							}
+						} else {
+							warn!("Skipping Polkadot genesis hash check");
+							break online_client
+						}
+					},
 					Err(e) => {
-						tracing::error!(
+						error!(
 						"Failed to connect to Polkadot node at {url} with error: {e}. Please check your CFE
 						configuration file. Retrying in {:?}...",
 						poll_interval.period()
@@ -201,7 +219,8 @@ mod tests {
 	#[ignore = "requires local node"]
 	#[tokio::test]
 	async fn test_http_rpc() {
-		let dot_http_rpc = DotHttpRpcClient::new("http://localhost:9945".into()).unwrap().await;
+		let dot_http_rpc =
+			DotHttpRpcClient::new("http://localhost:9945".into(), None).unwrap().await;
 		let block_hash = dot_http_rpc.block_hash(1).await.unwrap();
 		println!("block_hash: {:?}", block_hash);
 	}

engine/src/dot/retry_rpc.rs

@@ -44,6 +44,16 @@ impl DotRetryRpcClient {
 	pub fn new(
 		scope: &Scope<'_, anyhow::Error>,
 		nodes: NodeContainer<WsHttpEndpoints>,
+		expected_genesis_hash: PolkadotHash,
+	) -> Result<Self> {
+		Self::new_inner(scope, nodes, Some(expected_genesis_hash))
+	}
+
+	fn new_inner(
+		scope: &Scope<'_, anyhow::Error>,
+		nodes: NodeContainer<WsHttpEndpoints>,
+		// The genesis hash is optional to facilitate testing
+		expected_genesis_hash: Option<PolkadotHash>,
 	) -> Result<Self> {
 		let f_create_clients = |endpoints: WsHttpEndpoints| {
 			Result::<_, anyhow::Error>::Ok((
@@ -57,7 +67,7 @@ impl DotRetryRpcClient {
 		let (backup_rpc_client, backup_sub_client) =
 			option_inner(nodes.backup.map(f_create_clients).transpose()?);
 
-		Ok(Self {
+		Ok(DotRetryRpcClient {
 			rpc_retry_client: RetrierClient::new(
 				scope,
 				"dot_rpc",
@@ -306,7 +316,7 @@ mod tests {
 	async fn my_test() {
 		task_scope(|scope| {
 			async move {
-				let dot_retry_rpc_client = DotRetryRpcClient::new(
+				let dot_retry_rpc_client = DotRetryRpcClient::new_inner(
 					scope,
 					NodeContainer {
 						primary: WsHttpEndpoints {
@@ -315,6 +325,7 @@ mod tests {
 						},
 						backup: None,
 					},
+					None,
 				)
 				.unwrap();
 

engine/src/dot/rpc.rs

@@ -12,6 +12,7 @@ use subxt::{
 	Config, OnlineClient, PolkadotConfig,
 };
 use tokio::sync::RwLock;
+use tracing::warn;
 use utilities::redact_endpoint_secret::SecretUrl;
 
 use anyhow::{anyhow, Result};
@@ -136,11 +137,12 @@ impl DotRpcApi for DotRpcClient {
 #[derive(Clone)]
 pub struct DotSubClient {
 	pub ws_endpoint: SecretUrl,
+	expected_genesis_hash: Option<PolkadotHash>,
 }
 
 impl DotSubClient {
-	pub fn new(ws_endpoint: SecretUrl) -> Self {
-		Self { ws_endpoint }
+	pub fn new(ws_endpoint: SecretUrl, expected_genesis_hash: Option<PolkadotHash>) -> Self {
+		Self { ws_endpoint, expected_genesis_hash }
 	}
 }
 
@@ -149,7 +151,8 @@ impl DotSubscribeApi for DotSubClient {
 	async fn subscribe_best_heads(
 		&self,
 	) -> Result<Pin<Box<dyn Stream<Item = Result<PolkadotHeader>> + Send>>> {
-		let client = OnlineClient::<PolkadotConfig>::from_url(&self.ws_endpoint).await?;
+		let client = create_online_client(&self.ws_endpoint, self.expected_genesis_hash).await?;
+
 		Ok(Box::pin(
 			client
 				.blocks()
@@ -163,7 +166,8 @@ impl DotSubscribeApi for DotSubClient {
 	async fn subscribe_finalized_heads(
 		&self,
 	) -> Result<Pin<Box<dyn Stream<Item = Result<PolkadotHeader>> + Send>>> {
-		let client = OnlineClient::<PolkadotConfig>::from_url(&self.ws_endpoint).await?;
+		let client = create_online_client(&self.ws_endpoint, self.expected_genesis_hash).await?;
+
 		Ok(Box::pin(
 			client
 				.blocks()
@@ -175,6 +179,26 @@ impl DotSubscribeApi for DotSubClient {
 	}
 }
 
+/// Creates an OnlineClient from the given websocket endpoint and checks the genesis hash if
+/// provided.
+async fn create_online_client(
+	ws_endpoint: &SecretUrl,
+	expected_genesis_hash: Option<PolkadotHash>,
+) -> Result<OnlineClient<PolkadotConfig>> {
+	let client = OnlineClient::<PolkadotConfig>::from_url(ws_endpoint).await?;
+
+	if let Some(expected_genesis_hash) = expected_genesis_hash {
+		let genesis_hash = client.genesis_hash();
+		if genesis_hash != expected_genesis_hash {
+			bail!("Expected Polkadot genesis hash {expected_genesis_hash} but got {genesis_hash}");
+		}
+	} else {
+		warn!("Skipping Polkadot genesis hash check");
+	}
+
+	Ok(client)
+}
+
 #[async_trait]
 impl DotSubscribeApi for DotRpcClient {
 	async fn subscribe_best_heads(