Allow modal shell -c to run a command

[ekzhang]

This is analogous to python -c "print(3 + 4)", or also bash -c "echo hello".

Changelog

• modal shell --cmd now can be shortened to modal shell -c. This means you can use it like modal shell -c "uname -a" to quickly run a command within the remote environment.

[mwaskom]

I was chatting with someone yesterday and they mentioned confusion between modal shell and modal container exec. That made me me wonder whether modal shell --container=<container_id> would be more intuitive than modal container exec <container_id> /bin/bash for getting a shell in a running container. In which case you might want -c to be the short form of --container, which is a long word.

On the other hand, bash -c etc. is pretty common, so it probably makes sense to have this too. Just mentioning!

[ekzhang]

Makes sense, I could look at adding that! How about modal shell ta-123456 directly then, replacing FUNC_REF?

[mwaskom]

That could also work! Really just a non-blocking comment either way, was just top of mind.

[ekzhang]

@prbot approve

[modal-pr-review-automation]

Approved 👍. @freider will follow-up review this.