ssh: install an ssh client

[gmacon]

Fixes: #3667

Description

Add programs.ssh.package option and install the ssh client. It's not clear to me if this change is backwards-compatible or not, but at least we have something concrete to look at now.

Checklist

• Change is backwards compatible.

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[rycee]

Thanks! Merged to master now.

[nixos-discourse]

This pull request has been mentioned on NixOS Discourse. There might be relevant details there:

https://discourse.nixos.org/t/collision-between-ssh/28228/2

[thefloweringash]

Is there an easy way to turn this off? I want to use the version provided by Apple that provides integration with the macOS keychain. I tried setting programs.ssh.package = null, but that "is not of type `package'".

For now I'm using

{
  programs.ssh = { 
    package = pkgs.runCommand "home-manager-3668" {} ''
      mkdir $out
    '';
  };
}

[ncfavier]

There should be, and I think we shouldn't merge this until there is. See also #3375

[rycee]

I think using programs.ssh.package = pkgs.emptyDirectory is the best solution. You could always alias the emptyDirectory to something shorter or more descriptive, if you want. E.g., programs.ssh.package = pkgs.nil or programs.ssh.package = pkgs.intentionallyLeftEmpty.

[ncfavier]

NixOS/nixpkgs#232808

[lilyball]

Personally, I think this should just be reverted. SSH is usually installed at the system level, not the user level. And if I, as a user, want to use a different SSH client, I can just add it to home.packages myself.

The programs.ssh module is all about the user-level configuration for SSH, not about making SSH available to the system. Just because I want to configure SSH for my user shouldn't implicitly change the SSH client I'm using.

[ncfavier]

Suggesting a middle ground: #4016