Multi-process management in Docker containers (draft)

It is very simple to run multiple processes simultaneously in a traditional environment, and the system initializes an init or systemctl process, which is managed by the rest of the process. There is no init process in the container environment, start a Docker container, and only let it run a foreground program.
So is there a way to solve this problem?

There are currently two main tools, one is supervisor and the other is monit. This article first to introduce Supervisor,monit will be in the later article to do more detailed.

Multi-process management in Docker containers (draft)