Add SSH config format to server list command

[PaddyT]

I regularly find myself running a python script to update my ~/.ssh/config entries, whenever I create new servers on the Faculty platform. I thought it might be useful to contribute back and add it as a feature to the CLI.

Problem statment

Currently, if you create a new server and would like to access it remotely via SSH, you have to run a few separate commands:

1️⃣ Retrieve a list of your servers by name and (only with the verbose flag) their Project:

> faculty server list -v                                   
Project Name        Server Name       Type     Machine Type      CPUs  RAM    Status    Server ID            Started
My Project Name     server_name       jupyter  -                    1  4GB    running   some-server-id       2023-01-01 01:23

2️⃣ Retrieve an IP address for my server:

> faculty server ssh-details "Project Name" server_name
Hostname       Port  Username
12.34.56.78   12345  username

3️⃣ Copy-paste that IP address from my std output and then run my ssh command

> ssh username@12.34.56.78 -P 12345

This is a little cumbersome for workflows where you create/update your servers often.

Solution

My proposed change is to modify the faculty server list command, adding an extra --format option which supports returning a list of servers in a format which can be piped directly to a user's ssh_config file.
This is super useful for workflows where you create/update your servers often, since it allows you to "save" your server ssh details and propagate that info to places like your IDE or command line client.

Example:

> faculty server list  --format ssh-config
Host server_name-project_name
    HostName 12.34.56.78
    User username
    Port 12345

I've removed the --verbose flag, and moved retrieving the full table of server info to --format table, since it seemed overcomplicated to have both "verbose" and "format" tags.

[imrehg]

Changes from #57 should fix up the tests, just FYI.

[acroz]

Looks great, thanks for the contribution.

I'm wary of removing the -v flag with no deprecation period, and for the consistency of the CLI (which uses --verbose extensively elsewhere) I'm tempted to leave it in. Would you mind if we leave --verbose in, and error out in the case that both --verbose and --format are specified?

Separately, should we consider merging faculty server ssh-details into this? (with a warning on ssh-details that it's going to be removed)

[PaddyT]

I'm wary of removing the -v flag with no deprecation period, and for the consistency of the CLI (which uses --verbose extensively elsewhere) I'm tempted to leave it in. Would you mind if we leave --verbose in, and error out in the case that both --verbose and --format are specified?

Absolutely, makes sense. Done! The behaviour when you don't pass --format is now unchanged. Added test cases to make the new behaviour clear.

[acroz]

The existing behaviour deliberately only shows "No servers" in the verbose case, so that if you have a script consuming this output, it doesn't receive what looks like a single server called "No servers".

I think to keep existing behaviour we should have:

• For the old logic not found_servers and verbose printing "No servers" - add as a nested if not found_servers under if format == "table"
• For the old logic project and verbose printing a table with the first (project) column removed - as you've already implemented
• For the old logic project or not verbose printing a list of server names - as you've implemented under else: (but without the short circuit this comment is attached to - no servers should result in empty output)
• For the old logic not project and verbose printing a table printing a table including the first (project) column - as you've already implemented

Does this sound ok? Removing this short circuit would also result in the ssh-config format being valid in the case there are no matching servers.

[acroz]

I know this was missing from the current implementation, but could you include a comment that this is removing the project column from the output? It's not clear from the implementation.