I do a separate container for each service that requires a db. It’s pretty baked into my backup strategy at this point where the script I wrote references environment variables for dumps in a way that I don’t have to update it for every new service I deploy.

If the container name has -dbm on the end it’s MySQL, -dbp is postgres, and -dbs would be SQLite if it needed its own containers. The suffix triggers the appropriate backup command that pulls the user, password, and db name from environment variables in the container.

I’m not too concerned about system overhead, but I’m debating doing a single container for each db type just to do it, but I also like not having a single point of failure for all my services (I even run different VMs to keep stable services from being impacted by me testing random stuff out.)