> But what if the person who started the container didn't use docker-compose?

There's your shell history, combined with fzf this helps recall previously run commands. You can search for something like "docker redis" and find it in a few key strokes.

If the container got spawned by something else then I think that's reaching for "beyond-the-edge" edge cases. I've been using Docker since 2014 and worked with dozens of companies (contract work) related to using Docker and this scenario has happened 0 times where I wanted to be able to replicate the flags used to spawn a container but couldn't find the command. Nearly every container is spawned from using Docker Compose or it exists in your shell's history.