Stop firebase emulators gracefully when docker stop - firebase

Question

My Dockerfile installs firebase emulators. When stop firebase emulators, it should export data before exit.
# Skip installation: https://firebase.google.com/docs/emulator-suite/install_and_configure
CMD ["firebase", "emulators:start", "--import=./data", "--export-on-exit"]
If I run docker run -ti --name my-firebase-tools my-firebase-tools and then press Crtl-C, firebase emulators stops gracefully before container stops. Everything is ok.
But normally, I want to run docker run -d -ti --name my-firebase-tools my-firebase-tools, so the container will run in background.
In this case, if I run docker stop my-firebase-tools, no signal is sent to firebase to terminal firebase emulators, therefore no data is exported. Container stops after 10s with exit code 137.
docker run -d -ti --stop-signal SIGINT --name my-firebase-tools my-firebase-tools doesn't help.
Tried with entrypoint.sh below:
pid=0
sigterm_handler() {
if [ $pid -ne 0 ]; then
kill -SIGTERM "$pid"
wait "$pid"
fi
exit 143; # 128 + 15 -- SIGTERM
}
trap 'kill ${!}; sigterm_handler' SIGTERM
firebase emulators:start --import=./data --export-on-exit &
pid="$!"
# wait forever
while true
do
tail -f /dev/null & wait ${!}
done
the signal is trapped, sigterm_handler is called, but firebase still doesn't receive the termination signal.

Answer 1

This entrypoint solve the problem.
#!/bin/bash
loopPid=0
pid=0
sigterm_handler() {
pkill -P "$pid"
wait "$pid"
echo "sigterm handled gracefully"
exit 0;
}
trap 'sigterm_handler' SIGTERM
sigint_handler() {
wait "$pid"
wait "$loopPid"
echo "sigint handled gracefully"
exit 0;
}
trap 'sigint_handler' SIGINT
exec firebase emulators:start --import=./data --export-on-exit &
pid="$!"
# wait forever
tail -f /dev/null &
loopPid="$!"
wait "$loopPid"
echo "Not a gracefully shutdown"
exit 1;