nixpkgs/nixos/tests/apcupsd.nix

let
  # arbitrary address
  ipAddr = "192.168.42.42";
in
import ./make-test-python.nix (
  { lib, pkgs, ... }:
  {
    name = "apcupsd";
    meta.maintainers = with lib.maintainers; [ bjornfor ];

    nodes = {
      machine = {
        services.apcupsd = {
          enable = true;
          configText = ''
            UPSTYPE usb
            BATTERYLEVEL 42
            # Configure NISIP so that the only way apcaccess can work is to read
            # this config.
            NISIP ${ipAddr}
          '';
        };
        networking.interfaces.eth1 = {
          ipv4.addresses = [
            {
              address = ipAddr;
              prefixLength = 24;
            }
          ];
        };
      };
    };

    # Check that the service starts, that the CLI (apcaccess) works and that it
    # uses the config (ipAddr) defined in the service config.
    testScript = ''
      start_all()
      machine.wait_for_unit("apcupsd.service")
      machine.wait_for_open_port(3551, "${ipAddr}")
      res = machine.succeed("apcaccess")
      expect_line="MBATTCHG : 42 Percent"
      assert "MBATTCHG : 42 Percent" in res, f"expected apcaccess output to contain '{expect_line}' but got '{res}'"
      machine.shutdown()
    '';
  }
)