Set bind propagation mode for media (#4308)

* Set bind propagation mode for media

* Add some test cases

tests/docker/test_dns.py

@@ -0,0 +1,38 @@
+"""Test DNS plugin container."""
+
+from ipaddress import IPv4Address
+from pathlib import Path
+from unittest.mock import patch
+
+from docker.types import Mount
+
+from supervisor.coresys import CoreSys
+from supervisor.docker.manager import DockerAPI
+
+
+async def test_start(coresys: CoreSys, tmp_supervisor_data: Path, path_extern):
+    """Test starting dns plugin."""
+    config_file = tmp_supervisor_data / "dns" / "coredns.json"
+    assert not config_file.exists()
+
+    with patch.object(DockerAPI, "run") as run:
+        await coresys.plugins.dns.start()
+
+        run.assert_called_once()
+        assert run.call_args.kwargs["ipv4"] == IPv4Address("172.30.32.3")
+        assert run.call_args.kwargs["name"] == "hassio_dns"
+        assert run.call_args.kwargs["hostname"] == "hassio-dns"
+        assert run.call_args.kwargs["dns"] is False
+        assert run.call_args.kwargs["oom_score_adj"] == -300
+        assert run.call_args.kwargs["mounts"] == [
+            Mount(
+                type="bind",
+                source=coresys.config.path_extern_dns.as_posix(),
+                target="/config",
+                read_only=False,
+            ),
+            Mount(type="bind", source="/run/dbus", target="/run/dbus", read_only=True),
+        ]
+        assert "volumes" not in run.call_args.kwargs
+
+    assert config_file.exists()