home-assistant port doesn't do anything unless config is set

[Radvendii]

Describe the bug
If you set services.home-assistant.port = 4000 but you don't set services.home-assistant.config to anything, then nothing changes. You still have to access it on port 8123

To Reproduce
Steps to reproduce the behavior:

1. set

services.home-assistant = {
  enable = true;
  port = 4000;
};

2. sudo nixos-rebuild switch
3. check localhost:4000 and localhost:8123

Expected behavior
I will see the landing page on localhost:4000, and not on localhost:8123

Metadata

• system: "x86_64-linux"
• host os: Linux 5.4.23, NixOS, 20.09pre215947.82b54d49066 (Nightingale)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.3.3
• channels(root): "nixos-20.09pre215947.82b54d49066"
• channels(qolen): "home-manager, nixos-20.09pre215947.82b54d49066"
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos

Maintainer information:

# a list of nixpkgs attributes affected by the problem
attribute:
# a list of nixos modules affected by the problem
module: home-assistant

[matt-snider]

I can reproduce this issue with the following test. The test hangs while waiting for the port. I see the issue, which is caused primarily by the configuration.yaml file only being overwritten when cfg.config != null.

# nixos/tests/home-assistant-bug.nix
# run with: nix-build nixos/tests/home-assistant-bug.nix
import ./make-test-python.nix ({ pkgs, ... }:
{
  name = "home-assistant";

  nodes = {
    hass =
      { pkgs, ... }:
      {
        services.home-assistant = {
          enable = true;
          port = 4000;
        };
      };
  };

  testScript = ''
    start_all()
    hass.wait_for_unit("home-assistant.service")
    with subtest("Check that Home Assistant's web interface and API can be reached"):
        hass.wait_for_open_port(4000)
        hass.succeed("curl --fail http://localhost:4000")
  '';
})

[mweinelt]

The services.home-assistant.port option was removed in 59a367b in time for NixOS 22.05.