docker: move sigterm handling up to the entrypoint

Having it into the duniter.sh script prevents using duniter subcommands such as duniter wizard key which are then launched in the background.

Moving it into the entrypoint makes the subcommands available again.

release/docker/docker-entrypoint.sh

@@ -121,7 +121,18 @@ else
   set -- $MAX_OLD_SPACE_SIZE "$@"
 fi
 
+# Terminate gracefully on SIGTERM by propagating it to the 'node' process
+sigterm () {
+  echo "Received SIGTERM. Terminating..." >&2
+  pkill node
+  wait %1
+}
+trap 'sigterm' TERM
+
 # Start duniter
+# Launch in background and wait
+# This way we can catch SIGTERM
 echo Starting duniter with:
 echo /usr/bin/duniter "$@"
-exec /usr/bin/duniter "$@"
+/usr/bin/duniter "$@" &
+wait %1