git-submodules.nix

# Test Nix's remote build feature.

{ lib, hostPkgs, ... }:

{
  config = {
    name = lib.mkDefault "git-submodules";

    nodes = {
      remote =
        { config, pkgs, ... }:
        {
          services.openssh.enable = true;
          environment.systemPackages = [ pkgs.git ];
        };

      client =
        {
          config,
          lib,
          pkgs,
          ...
        }:
        {
          programs.ssh.extraConfig = "ConnectTimeout 30";
          environment.systemPackages = [ pkgs.git ];
          nix.extraOptions = "experimental-features = nix-command flakes";
        };
    };

    testScript =
      { nodes }:
      ''
        # fmt: off
        import subprocess

        start_all()

        # Create an SSH key on the client.
        subprocess.run([
          "${hostPkgs.openssh}/bin/ssh-keygen", "-t", "ed25519", "-f", "key", "-N", ""
        ], capture_output=True, check=True)
        client.succeed("mkdir -p -m 700 /root/.ssh")
        client.copy_from_host("key", "/root/.ssh/id_ed25519")
        client.succeed("chmod 600 /root/.ssh/id_ed25519")

        # Install the SSH key on the builders.
        client.wait_for_unit("network-addresses-eth1.service")

        remote.succeed("mkdir -p -m 700 /root/.ssh")
        remote.copy_from_host("key.pub", "/root/.ssh/authorized_keys")
        remote.wait_for_unit("sshd")
        remote.wait_for_unit("multi-user.target")
        remote.wait_for_unit("network-addresses-eth1.service")
        client.wait_for_unit("network-addresses-eth1.service")
        client.succeed(f"ssh -o StrictHostKeyChecking=no {remote.name} 'echo hello world'")

        remote.succeed("""
          git init bar
          git -C bar config user.email foobar@example.com
          git -C bar config user.name Foobar
          echo test >> bar/content
          git -C bar add content
          git -C bar commit -m 'Initial commit'
        """)

        client.succeed(f"""
          git init foo
          git -C foo config user.email foobar@example.com
          git -C foo config user.name Foobar
          git -C foo submodule add root@{remote.name}:/tmp/bar sub
          git -C foo add sub
          git -C foo commit -m 'Add submodule'
        """)

        client.succeed("nix --flake-registry \"\" flake prefetch 'git+file:///tmp/foo?submodules=1&ref=master'")
      '';
  };
}