nixpkgs/nixos/tests/containers-reloadable.nix

import ./make-test-python.nix (
  { pkgs, lib, ... }:
  {
    name = "containers-reloadable";
    meta = {
      maintainers = with lib.maintainers; [ danbst ];
    };

    nodes = {
      machine =
        { lib, ... }:
        {
          containers.test1 = {
            autoStart = true;
            config.environment.etc.check.text = "client_base";
          };

          # prevent make-test-python.nix to change IP
          networking.interfaces.eth1.ipv4.addresses = lib.mkOverride 0 [ ];

          specialisation.c1.configuration = {
            containers.test1.config = {
              environment.etc.check.text = lib.mkForce "client_c1";
              services.httpd.enable = true;
              services.httpd.adminAddr = "nixos@example.com";
            };
          };

          specialisation.c2.configuration = {
            containers.test1.config = {
              environment.etc.check.text = lib.mkForce "client_c2";
              services.nginx.enable = true;
            };
          };
        };
    };

    testScript = ''
      machine.start()
      machine.wait_for_unit("default.target")

      assert "client_base" in machine.succeed("nixos-container run test1 cat /etc/check")

      with subtest("httpd is available after activating config1"):
          machine.succeed(
              "/run/booted-system/specialisation/c1/bin/switch-to-configuration test >&2",
              "[[ $(nixos-container run test1 cat /etc/check) == client_c1 ]] >&2",
              "systemctl status httpd -M test1 >&2",
          )

      with subtest("httpd is not available any longer after switching to config2"):
          machine.succeed(
              "/run/booted-system/specialisation/c2/bin/switch-to-configuration test >&2",
              "[[ $(nixos-container run test1 cat /etc/check) == client_c2 ]] >&2",
              "systemctl status nginx -M test1 >&2",
          )
          machine.fail("systemctl status httpd -M test1 >&2")
    '';

  }
)