Handle SIGTERM for the docker containers + relay (paritytech#1735)

* Handle SIGTERM for some docker containers

* Implement SIGTERM handling for the relay

deployments/bridges/common/generate_messages.sh

@@ -17,11 +17,13 @@
 
 SECONDARY_EXTRA_ARGS=${SECONDARY_EXTRA_ARGS:-""}
 
+trap "echo Exiting... TERM; exit $?" TERM
+
 # Sleep a bit between messages
 rand_sleep() {
 	SUBMIT_DELAY_S=`shuf -i 0-$MAX_SUBMIT_DELAY_S -n 1`
 	echo "Sleeping $SUBMIT_DELAY_S seconds..."
-	sleep $SUBMIT_DELAY_S
+	sleep $SUBMIT_DELAY_S & wait $!
 	NOW=`date "+%Y-%m-%d %H:%M:%S"`
 	echo "Woke up at $NOW"
 }

deployments/bridges/rialto-parachain-millau/entrypoints/relay-messages-to-rialto-parachain-resubmitter-entrypoint.sh

@@ -15,7 +15,7 @@ sleep 15
 # we need tip around `526186677695 - 17800827994 = 508_385_849_701`. Let's round it
 # up to `1_000_000_000_000`.
 
-/home/user/substrate-relay resubmit-transactions millau \
+exec /home/user/substrate-relay resubmit-transactions millau \
 	--target-host millau-node-alice \
 	--target-port 9944 \
 	--target-signer //RialtoParachain.MessagesSender \

deployments/bridges/rialto-parachain-millau/entrypoints/relay-millau-rialto-parachain-entrypoint.sh

@@ -24,7 +24,7 @@ RIALTO_PARACHAIN_RELAY_ACCOUNT=${EXT_RIALTO_PARACHAIN_RELAY_ACCOUNT:-//Millau.He
 # Give chain a little bit of time to process initialization transaction
 sleep 6
 
-/home/user/substrate-relay relay-headers-and-messages millau-rialto-parachain \
+exec /home/user/substrate-relay relay-headers-and-messages millau-rialto-parachain \
 	--millau-host millau-node-alice \
 	--millau-port 9944 \
 	--millau-signer $MILLAU_RELAY_ACCOUNT \

deployments/monitoring/docker-compose.yml

@@ -20,6 +20,8 @@ services:
       - "3000:3000"
     depends_on:
       - prometheus-metrics
+    # SIGTERM won't work because of our custom entrypoint. Should be ok to use SIGKILL.
+    stop_signal: SIGKILL
     entrypoint: sh -c "echo 'sleeping for 10m' && sleep 600 && /run.sh"
 
   grafana-matrix-notifier:

deployments/networks/entrypoints/rialto-chainspec-exporter-entrypoint.sh

@@ -1,6 +1,8 @@
 #!/bin/bash
 set -xeu
 
+trap "echo Exiting... TERM; exit $?" TERM
+
 /home/user/rialto-bridge-node build-spec \
 	--chain local \
 	--raw \
@@ -11,4 +13,4 @@ set -xeu
 # by the container running this script. If this script ends, the volume will be detached
 # and our chain spec will be lost when it'll go online again. Hence the never-ending
 # script which keeps volume online until container is stopped.
-tail -f /dev/null
+tail -f /dev/null & wait $!

deployments/networks/entrypoints/rialto-parachain-registrar-entrypoint.sh

@@ -3,7 +3,7 @@ set -xeu
 
 sleep 15
 
-/home/user/substrate-relay register-parachain rialto-parachain \
+exec /home/user/substrate-relay register-parachain rialto-parachain \
 	--parachain-host rialto-parachain-collator-alice \
 	--parachain-port 9944 \
 	--relaychain-host rialto-node-alice \

deployments/ui/docker-compose.yml

@@ -9,5 +9,6 @@ services:
       LETSENCRYPT_EMAIL: admin@parity.io
       CHAIN_1_SUBSTRATE_PROVIDER: ${UI_CHAIN_1:-ws://localhost:9944}
       CHAIN_2_SUBSTRATE_PROVIDER: ${UI_CHAIN_2:-ws://localhost:19944}
+    stop_signal: SIGKILL
     ports:
       - "8080:80"

relays/bin-substrate/Cargo.toml

@@ -16,6 +16,8 @@ log = "0.4.17"
 num-format = "0.4"
 num-traits = "0.2"
 structopt = "0.3"
+signal-hook = "0.3.14"
+signal-hook-async-std = "0.2.2"
 strum = { version = "0.21.0", features = ["derive"] }
 
 # Bridge dependencies

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

@@ -18,7 +18,11 @@
 
 use std::convert::TryInto;
 
+use async_std::prelude::*;
 use codec::{Decode, Encode};
+use futures::{select, FutureExt};
+use signal_hook::consts::*;
+use signal_hook_async_std::Signals;
 use structopt::{clap::arg_enum, StructOpt};
 use strum::{EnumString, EnumVariantNames};
 
@@ -37,6 +41,9 @@ mod relay_messages;
 mod relay_parachains;
 mod resubmit_transactions;
 
+/// The target that will be used when publishing logs related to this pallet.
+pub const LOG_TARGET: &str = "bridge";
+
 /// Parse relay CLI args.
 pub fn parse_args() -> Command {
 	Command::from_args()
@@ -100,8 +107,7 @@ impl Command {
 	}
 
 	/// Run the command.
-	pub async fn run(self) -> anyhow::Result<()> {
-		self.init_logger();
+	async fn do_run(self) -> anyhow::Result<()> {
 		match self {
 			Self::RelayHeaders(arg) => arg.run().await?,
 			Self::RelayMessages(arg) => arg.run().await?,
@@ -114,6 +120,32 @@ impl Command {
 		}
 		Ok(())
 	}
+
+	/// Run the command.
+	pub async fn run(self) {
+		self.init_logger();
+
+		let exit_signals = match Signals::new([SIGINT, SIGTERM]) {
+			Ok(signals) => signals,
+			Err(e) => {
+				log::error!(target: LOG_TARGET, "Could not register exit signals: {}", e);
+				return
+			},
+		};
+		let run = self.do_run().fuse();
+		futures::pin_mut!(exit_signals, run);
+
+		select! {
+			signal = exit_signals.next().fuse() => {
+				log::info!(target: LOG_TARGET, "Received exit signal {:?}", signal);
+			},
+			result = run => {
+				if let Err(e) = result {
+					log::error!(target: LOG_TARGET, "substrate-relay: {}", e);
+				}
+			},
+		}
+	}
 }
 
 arg_enum! {

relays/bin-substrate/src/main.rs

@@ -24,8 +24,5 @@ mod cli;
 fn main() {
 	let command = cli::parse_args();
 	let run = command.run();
-	let result = async_std::task::block_on(run);
-	if let Err(error) = result {
-		log::error!(target: "bridge", "substrate-relay: {}", error);
-	}
+	async_std::task::block_on(run);
 }