Consider adding multiple SSH keys

[hausdorff]

It's frequently true that I want to spin up (e.g.) a cluster for the team. Currently I seem to only be able to provide 1 SSH key, which means I have to go add the rest manually.

I'm not sure if it's possible to change the template to generalize this, but it would be really convenient if so.

[mattmoyer]

+1, this would probably mean moving away from the builtin EC2 SSH key metadata and doing our own thing with user data.

I'd also love to even get away from needing to enable SSH at all by default.