Add signal-handling ENTRYPOINT, cancel on QUIT

Dockerfile

@@ -61,5 +61,6 @@ ENV [email protected]
 VOLUME /code
 WORKDIR /code
 
-ENTRYPOINT ["/bin/restyler"]
+COPY entrypoint.sh /entrypoint.sh
+ENTRYPOINT ["/entrypoint.sh"]
 CMD ["--help"]

bin/check-cancellation

@@ -0,0 +1,32 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+docker build --tag restyled/restyler:test .
+
+export AWS_PROFILE=restyled
+
+echo "Launching Restyler"
+(restyled promote --image restyled/restyler:test stable |& ts >/tmp/run.log) &
+pid=$!
+echo "PID $pid"
+
+cid=
+
+echo "Waiting for Container"
+while [ -z "$cid" ]; do
+  sleep 1
+  cid=$(docker ps | awk '/restyled\/restyler:test/ { print $1 }')
+done
+echo "Container Id: $cid"
+echo "Letting run..."
+sleep 15
+
+echo "Sending SIGQUIT..."
+docker kill --signal SIGQUIT "$cid"
+# echo "Sending SIGSTOP..."
+# docker kill --signal SIGSTOP "$cid"
+# echo "Sending USR1..."
+# docker kill --signal USR1 "$cid"
+
+wait "$pid"
+echo "Restyler stopped."

entrypoint.sh

@@ -0,0 +1,15 @@
+#!/bin/sh
+: "${RESTYLER_CANCEL_SIGNAL:=QUIT}"
+
+for signal in $(kill -l); do
+  if [ "$signal" != "$RESTYLER_CANCEL_SIGNAL" ]; then
+    # Best-effort forward all signals we don't handle
+    trap 'kill -'"$signal"' "$restyler_pid" 2>/dev/null' "$signal"
+  fi
+done
+
+trap 'echo "Build canceled."; exit 0' "$RESTYLER_CANCEL_SIGNAL"
+
+/bin/restyler "$@" &
+restyler_pid=$!
+wait "$restyler_pid"