Just stumbled over this: https://hynek.me/articles/docker-signals/ by @hynekHynek Schlawack
If you ever wanted to know why a dockerfile starts an app with "dumb" in the name and have moments like "why did my app disappear without any warning in k8s", this post is for you.
Reading this a few years ago would have left me with a few more productive / joyful days in my memory instead of painfully figuring this out on my own.

Why Your Dockerized Application Isn’t Receiving Signals
Proper cleanup when terminating your application isn’t less important when it’s running inside of a Docker container. Although it only comes down to making sure signals reach your application and handling them, there’s a bunch of things that can go wrong.
hynek.me · Hynek Schlawack
Link author: Hynek Schlawack@hynek@mastodon.social