The most important thing I know about signals is that in dockerized applications, your ENTRYPOINT or CMD must use the exec form (`["command", "arg1", "arg2"]`) in order for your application to receive signals.

A lot of applications, like web/API frameworks, will gracefully shutdown if they receive SIGTERM or SIGINT, but if that signal doesn't propagate to the app you'll need to SIGKILL instead. Kubernetes will do this for you, waiting for your process to shutdown and then ungracefully killing it when it doesn't do so in time.

But you can't do env var substitution with the exec form...