Create issue for detected DNS server problem (#3578)

* Create issue for detected DNS server problem

* Validate behavior on restart as well

* tls:// not supported, remove check

* Move DNS server checks into resolution checks

* Revert all changes to plugins.dns

* Run DNS server checks if affected

* Mock aiodns query during all checks tests

tests/plugins/test_dns.py

@@ -0,0 +1,55 @@
+"""Test DNS plugin."""
+from pathlib import Path
+from unittest.mock import AsyncMock, Mock, patch
+
+import pytest
+
+from supervisor.coresys import CoreSys
+from supervisor.docker.interface import DockerInterface
+
+
+@pytest.fixture(name="docker_interface")
+async def fixture_docker_interface() -> tuple[AsyncMock, AsyncMock]:
+    """Mock docker interface methods."""
+    # with patch("supervisor.docker.interface.DockerInterface.run"), patch("supervisor.docker.interface.DockerInterface.restart")
+    with patch.object(DockerInterface, "run") as run, patch.object(
+        DockerInterface, "restart"
+    ) as restart:
+        yield (run, restart)
+
+
+@pytest.fixture(name="write_json")
+async def fixture_write_json() -> Mock:
+    """Mock json file writer."""
+    with patch("supervisor.plugins.dns.write_json_file") as write_json_file:
+        yield write_json_file
+
+
+@pytest.mark.parametrize("start", [True, False])
+async def test_config_write(
+    coresys: CoreSys,
+    docker_interface: tuple[AsyncMock, AsyncMock],
+    write_json: Mock,
+    start: bool,
+):
+    """Test config write on DNS start and restart."""
+    assert coresys.plugins.dns.locals == ["dns://192.168.30.1"]
+    coresys.plugins.dns.servers = ["dns://1.1.1.1", "dns://8.8.8.8"]
+
+    if start:
+        await coresys.plugins.dns.start()
+        docker_interface[0].assert_called_once()
+        docker_interface[1].assert_not_called()
+    else:
+        await coresys.plugins.dns.restart()
+        docker_interface[0].assert_not_called()
+        docker_interface[1].assert_called_once()
+
+    write_json.assert_called_once_with(
+        Path("/data/dns/coredns.json"),
+        {
+            "servers": ["dns://1.1.1.1", "dns://8.8.8.8"],
+            "locals": ["dns://192.168.30.1"],
+            "debug": False,
+        },
+    )