Add remote ssh port as configuration parameter

[artem-zinnatullin]

Right now we fully rely on ~/.ssh/config implicitly processed by ssh and the fact that default port is 22, adding it on our config level will allow project-specific overrides as part of #213.

[arturdryomov]

Not sure what the use case there is. Multiple ports on the remote machine?

[artem-zinnatullin]

Well, not everyone maintains ~/.ssh/config for every host, ie I have couple hosts I ssh into that have ssh running on non standard port and I don't have them in my ~/.ssh/config

[arturdryomov]

I would still suggest to configure SSH for this. Then the configuration can be applied not only to MF. Using a remote machine still involves using SSH from time to time — to clear caches, kill processes, test excutables. We even mention using SSH to test the connection before configuring MF in the first place.

[artem-zinnatullin]

The reason why I want to allow configuring these things on Mainframer side (including cli params),

is to make Mainframer more friendly for automation in different environments, including CI or scripts, etc where configuring ~/.ssh/config may be unreasonable

[arturdryomov]

That’s understandable for sure, but at the same time it either means password-based auth and no performance improvements like ControlPersist.

[arturdryomov]

Before I forgot. There is a middleground. We can provide an option to create SSH key and put everything in .ssh/config for the user. Not sure it is worth it but probably can save some hassle.

[artem-zinnatullin]

but at the same time it either means password-based auth

That's not true, default ssh key (~/.ssh/id_rsa) will be used without an entry in ~/.ssh/config for the remote host, which is what a lot of people use for everything, like GitHub.

no performance improvements like ControlPersist

True, prob not very important for automation setups and is configurable anyway if they want.

Before I forgot. There is a middleground. We can provide an option to create SSH key and put everything in .ssh/config for the user. Not sure it is worth it but probably can save some hassle.

Definitely not going to do that lol, that's a lot of work and potentially a security issue if we do it wrong.

We can hide SSH as implementation detail or embrace it, so far you (and I) have done the latter and it's just me bothering with some comments on your PRs to make ~/.ssh/config not look like strict requirement in setup docs :D