Merge pull request 'fix(entrypoint): exec memcached so docker stop is graceful' (#4) from fix/graceful-stop into trunk

scripts/entrypoint.sh

@@ -1,6 +1,8 @@
 #!/bin/bash
 echo "Starting Memcached..."
 sleep 5
-/usr/bin/memcached -u memcached -l 0.0.0.0
-
-exit 0
+# exec so memcached replaces bash as PID 1. bash as PID 1 has no SIGTERM
+# handler, so the kernel dropped `docker stop`'s SIGTERM and docker SIGKILLed
+# the container after the full 10s timeout (exit 137). memcached installs its
+# own SIGTERM/SIGINT handlers, so as PID 1 it shuts down immediately.
+exec /usr/bin/memcached -u memcached -l 0.0.0.0