The problem isn't when your main docker process is dying (in this case I believe dockerd itself reaps the process), the problem is when your service spawns chil

The problem isn't when your main docker process is dying (in this case I believe dockerd itself reaps the process), the problem is when your service spawns child processes as part of normal operation. As an example, suppose we have a simple web server that executes CGI scripts written in bash (I know this is kinda contrived but it illustrates my point). I do a request to the server, it runs a bash script. The script runs grep. While grep is executing, the web server decides bash has taken too long and SIGKILLs it. Then grep is adopted by your PID1, in this case your webserver. But the webserver doesn't know its there, and so never calls wait(). You now have a zombie process that will last until you stop the container.