kola: support for ssh RSA key types other than RSA-SHA1

[dustymabe]

Basically we need to support a key type other than RSA-SHA1 so that kola can ssh in to F33+.

The short term plan is to only re-enable RSA-SHA1 briefly while we wait for an upstream feature [1] to be implemented. We had moved to an ecdsa key [2] but AWS doesn't support non RSA keys [3] so we reverted it for now in [4].

[1] golang/go#37278 (comment)
[2] #1749
[3] https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-key-pairs.html#how-to-generate-your-own-key-and-import-it-to-aws
[4] #1767

Once the upstream golang issue is fixed let's pick up that work in mantle/kola.

[darkmuggle]

@dustymabe isn't this closed with #1749?

[dustymabe]

@dustymabe isn't this closed with #1749?

See #1767

[dustymabe]

Temporarily worked around this in the configs. This is a very short term change. We don't want to have f33 go to testing or stable with it in place.

[dustymabe]

Benjamin pointed out that the changes in Fedora and eventually openssh don't actually mean we have to change the key we're generating, but rather the key exchange algorithm. In order to do that we need to update our ssh client (kola use of the ssh library in this case) to use the new preferred algorithms. It seems we do still want the code referenced in my comment at golang/go#37278 (comment) so we can update kola to do that. So this issue still stands and we'll monitor to see if that code lands this week or next week. If not, we'll switch to an ecdsa key and just disable the afterburn ssh key test for now.

cc @bgilbert for fact checking.

[bgilbert]

Right. We could disable the Afterburn test exclusively on AWS. It's possible that we might still need to pass AWS a fake RSA key to make the API happy.

[dustymabe]

ok we're working around this temporarily by using an ecdsa key for Ignition/other cloud providers and using a throwaway key for AWS, and also disabling the fcos.ignition.v3.noop test on AWS. We should be able to revert the "workaround" commit and go back to using a single rsa key when we update the golang libraries.