Separate signers for different complex relay layers (#1465)

* separate accounts for different complex relay layers

* fix clippy issue

* cleanup + expose relay accounts balance metrics

* expose messages pallet owner balance metric

* use new metrics in maintenance dashboard

* tests + use separate accounts to sign RialtoHeaders -> Millau transactions in RialtoParachain<>Millau bridge

* clippy + fmt + spellcheck

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

@@ -48,3 +48,61 @@ pub struct TransactionParams<TS> {
 	/// Transactions mortality.
 	pub mortality: Option<u32>,
 }
+
+/// Tagged relay account, which balance may be exposed as metrics by the relay.
+#[derive(Clone, Debug)]
+pub enum TaggedAccount<AccountId> {
+	/// Account, used to sign headers relay transactions from given bridged chain.
+	Headers {
+		/// Account id.
+		id: AccountId,
+		/// Name of the bridged chain, which headers are relayed.
+		bridged_chain: String,
+	},
+	/// Account, used to sign parachains relay transactions from given bridged relay chain.
+	Parachains {
+		/// Account id.
+		id: AccountId,
+		/// Name of the bridged relay chain with parachain heads.
+		bridged_chain: String,
+	},
+	/// Account, used to sign message relay transactions from given bridged chain.
+	Messages {
+		/// Account id.
+		id: AccountId,
+		/// Name of the bridged chain, which sends us messages or delivery confirmations.
+		bridged_chain: String,
+	},
+	/// Account, used to sign messages with-bridged-chain pallet parameters update transactions.
+	MessagesPalletOwner {
+		/// Account id.
+		id: AccountId,
+		/// Name of the chain, bridged using messages pallet at our chain.
+		bridged_chain: String,
+	},
+}
+
+impl<AccountId> TaggedAccount<AccountId> {
+	/// Returns reference to the account id.
+	pub fn id(&self) -> &AccountId {
+		match *self {
+			TaggedAccount::Headers { ref id, .. } => id,
+			TaggedAccount::Parachains { ref id, .. } => id,
+			TaggedAccount::Messages { ref id, .. } => id,
+			TaggedAccount::MessagesPalletOwner { ref id, .. } => id,
+		}
+	}
+
+	/// Returns stringified account tag.
+	pub fn tag(&self) -> String {
+		match *self {
+			TaggedAccount::Headers { ref bridged_chain, .. } => format!("{}Headers", bridged_chain),
+			TaggedAccount::Parachains { ref bridged_chain, .. } =>
+				format!("{}Parachains", bridged_chain),
+			TaggedAccount::Messages { ref bridged_chain, .. } =>
+				format!("{}Messages", bridged_chain),
+			TaggedAccount::MessagesPalletOwner { ref bridged_chain, .. } =>
+				format!("{}MessagesPalletOwner", bridged_chain),
+		}
+	}
+}

bridges/relays/lib-substrate-relay/src/messages_metrics.rs

@@ -16,7 +16,7 @@
 
 //! Tools for supporting message lanes between two Substrate-based chains.
 
-use crate::{helpers::tokens_conversion_rate, messages_lane::SubstrateMessageLane};
+use crate::{helpers::tokens_conversion_rate, messages_lane::SubstrateMessageLane, TaggedAccount};
 
 use codec::Decode;
 use frame_system::AccountInfo;
@@ -274,13 +274,12 @@ pub fn standalone_metrics<P: SubstrateMessageLane>(
 pub async fn add_relay_balances_metrics<C: ChainWithBalances>(
 	client: Client<C>,
 	metrics: MetricsParams,
-	relay_account_id: Option<AccountIdOf<C>>,
-	messages_pallet_owner_account_id: Option<AccountIdOf<C>>,
+	relay_accounts: Vec<TaggedAccount<AccountIdOf<C>>>,
 ) -> anyhow::Result<MetricsParams>
 where
 	BalanceOf<C>: Into<u128> + std::fmt::Debug,
 {
-	if relay_account_id.is_none() && messages_pallet_owner_account_id.is_none() {
+	if relay_accounts.is_empty() {
 		return Ok(metrics)
 	}
 
@@ -306,26 +305,18 @@ where
 			e,
 		)
 	})?;
-	if let Some(relay_account_id) = relay_account_id {
+
+	for account in relay_accounts {
 		let relay_account_balance_metric = FloatStorageValueMetric::new(
 			FreeAccountBalance::<C> { token_decimals, _phantom: Default::default() },
 			client.clone(),
-			C::account_info_storage_key(&relay_account_id),
-			format!("at_{}_relay_balance", C::NAME),
-			format!("Balance of the relay account at the {}", C::NAME),
+			C::account_info_storage_key(account.id()),
+			format!("at_{}_relay_{}_balance", C::NAME, account.tag()),
+			format!("Balance of the {} relay account at the {}", account.tag(), C::NAME),
 		)?;
 		relay_account_balance_metric.register_and_spawn(&metrics.registry)?;
 	}
-	if let Some(messages_pallet_owner_account_id) = messages_pallet_owner_account_id {
-		let pallet_owner_account_balance_metric = FloatStorageValueMetric::new(
-			FreeAccountBalance::<C> { token_decimals, _phantom: Default::default() },
-			client.clone(),
-			C::account_info_storage_key(&messages_pallet_owner_account_id),
-			format!("at_{}_messages_pallet_owner_balance", C::NAME),
-			format!("Balance of the messages pallet owner at the {}", C::NAME),
-		)?;
-		pallet_owner_account_balance_metric.register_and_spawn(&metrics.registry)?;
-	}
+
 	Ok(metrics)
 }