nixos/home-assistant: reload the daemon when configuration changed

Reload the service when configuration changes. This means that we don't
have a potentially slow startup for every small configuration change.

1 files changed, 31 insertions, 1 deletions

diff --git a/nixos/tests/home-assistant.nix b/nixos/tests/home-assistant.nix
index f7b9d283e4572..341374e636aed 100644
--- a/nixos/tests/home-assistant.nix
+++ b/nixos/tests/home-assistant.nix
@@ -98,9 +98,26 @@ in {
       };
       lovelaceConfigWritable = true;
     };
+
+    # Cause a configuration change inside `configuration.yml` and verify that the process is being reloaded.
+    specialisation.differentName = {
+      inheritParentConfig = true;
+      configuration.services.home-assistant.config.homeassistant.name = lib.mkForce "Test Home";
+    };
+
+    # Cause a configuration change that requires a service restart as we added a new runtime dependency
+    specialisation.newFeature = {
+      inheritParentConfig = true;
+      configuration.services.home-assistant.config.device_tracker = [
+        { platform = "bluetooth_tracker"; }
+      ];
+    };
   };
 
-  testScript = ''
+  testScript = { nodes, ... }: let
+    system = nodes.hass.config.system.build.toplevel;
+  in
+  ''
     import re
 
     start_all()
@@ -142,6 +159,19 @@ in {
     with subtest("Check extra components are considered in systemd unit hardening"):
         hass.succeed("systemctl show -p DeviceAllow home-assistant.service | grep -q char-ttyUSB")
 
+    with subtest("Check service reloads when configuration changes"):
+      # store the old pid of the process
+      pid = hass.succeed("systemctl show --property=MainPID home-assistant.service")
+      hass.succeed("${system}/specialisation/differentName/bin/switch-to-configuration test")
+      new_pid = hass.succeed("systemctl show --property=MainPID home-assistant.service")
+      assert pid == new_pid, "The PID of the process should not change between process reloads"
+
+    with subtest("check service restarts when package changes"):
+      pid = new_pid
+      hass.succeed("${system}/specialisation/newFeature/bin/switch-to-configuration test")
+      new_pid = hass.succeed("systemctl show --property=MainPID home-assistant.service")
+      assert pid != new_pid, "The PID of the process shoudl change when the HA binary changes"
+
     with subtest("Print log to ease debugging"):
         output_log = hass.succeed("cat ${configDir}/home-assistant.log")
         print("\n### home-assistant.log ###\n")