[nsonha]

installing new tools inside container requires you to update the Dockerfile and rebuild, here it seems you can simply run the installation command and create a checkpoint

[fulafel]

You can do this with Docker too without Dockerfile or rebuilding. You can treat the container as mutable and just start/stop it, doing changes manually, and make snapshots with docker commit.

You'll forfeit the benefits of reproducible scripted environment of course but Docker does let you do it.