Use the shared zeroconf instance when attempting to create another Zeroconf instance

homeassistant/components/zeroconf/__init__.py

@@ -30,6 +30,8 @@
 from homeassistant.helpers.singleton import singleton
 from homeassistant.loader import async_get_homekit, async_get_zeroconf
 
+from .usage import install_multiple_zeroconf_catcher
+
 _LOGGER = logging.getLogger(__name__)
 
 DOMAIN = "zeroconf"
@@ -135,6 +137,8 @@ def setup(hass, config):
         ipv6=zc_config.get(CONF_IPV6, DEFAULT_IPV6),
     )
 
+    install_multiple_zeroconf_catcher(zeroconf)
+
     # Get instance UUID
     uuid = asyncio.run_coroutine_threadsafe(
         hass.helpers.instance_id.async_get(), hass.loop

homeassistant/components/zeroconf/usage.py

@@ -0,0 +1,50 @@
+"""Zeroconf usage utility to warn about multiple instances."""
+
+import logging
+
+import zeroconf
+
+from homeassistant.helpers.frame import (
+    MissingIntegrationFrame,
+    get_integration_frame,
+    report_integration,
+)
+
+_LOGGER = logging.getLogger(__name__)
+
+
+def install_multiple_zeroconf_catcher(hass_zc) -> None:
+    """Wrap the Zeroconf class to return the shared instance if multiple instances are detected."""
+
+    def new_zeroconf_new(self, *k, **kw):
+        _report(
+            "attempted to create another Zeroconf instance. Please use the shared Zeroconf via await homeassistant.components.zeroconf.async_get_instance(hass)",
+        )
+        return hass_zc
+
+    def new_zeroconf_init(self, *k, **kw):
+        return
+
+    zeroconf.Zeroconf.__new__ = new_zeroconf_new
+    zeroconf.Zeroconf.__init__ = new_zeroconf_init
+
+
+def _report(what: str) -> None:
+    """Report incorrect usage.
+
+    Async friendly.
+    """
+    integration_frame = None
+
+    try:
+        integration_frame = get_integration_frame(exclude_integrations={"zeroconf"})
+    except MissingIntegrationFrame:
+        pass
+
+    if not integration_frame:
+        _LOGGER.warning(
+            "Detected code that %s. Please report this issue.", what, stack_info=True
+        )
+        return
+
+    report_integration(what, integration_frame)

homeassistant/helpers/frame.py

@@ -3,7 +3,7 @@
 import functools
 import logging
 from traceback import FrameSummary, extract_stack
-from typing import Any, Callable, Tuple, TypeVar, cast
+from typing import Any, Callable, Optional, Tuple, TypeVar, cast
 
 from homeassistant.exceptions import HomeAssistantError
 
@@ -12,15 +12,24 @@
 CALLABLE_T = TypeVar("CALLABLE_T", bound=Callable)  # pylint: disable=invalid-name
 
 
-def get_integration_frame() -> Tuple[FrameSummary, str, str]:
+def get_integration_frame(
+    exclude_integrations: Optional[set] = None,
+) -> Tuple[FrameSummary, str, str]:
     """Return the frame, integration and integration path of the current stack frame."""
     found_frame = None
+    if not exclude_integrations:
+        exclude_integrations = set()
 
     for frame in reversed(extract_stack()):
         for path in ("custom_components/", "homeassistant/components/"):
             try:
                 index = frame.filename.index(path)
-                found_frame = frame
+                start = index + len(path)
+                end = frame.filename.index("/", start)
+                integration = frame.filename[start:end]
+                if integration not in exclude_integrations:
+                    found_frame = frame
+
                 break
             except ValueError:
                 continue
@@ -31,11 +40,6 @@ def get_integration_frame() -> Tuple[FrameSummary, str, str]:
     if found_frame is None:
         raise MissingIntegrationFrame
 
-    start = index + len(path)
-    end = found_frame.filename.index("/", start)
-
-    integration = found_frame.filename[start:end]
-
     return found_frame, integration, path
 
 
@@ -49,11 +53,24 @@ def report(what: str) -> None:
     Async friendly.
     """
     try:
-        found_frame, integration, path = get_integration_frame()
+        integration_frame = get_integration_frame()
     except MissingIntegrationFrame:
         # Did not source from an integration? Hard error.
         raise RuntimeError(f"Detected code that {what}. Please report this issue.")
 
+    report_integration(what, integration_frame)
+
+
+def report_integration(
+    what: str, integration_frame: Tuple[FrameSummary, str, str]
+) -> None:
+    """Report incorrect usage in an integration.
+
+    Async friendly.
+    """
+
+    found_frame, integration, path = integration_frame
+
     index = found_frame.filename.index(path)
     if path == "custom_components/":
         extra = " to the custom component author"

tests/components/conftest.py

@@ -1,8 +1,15 @@
 """Fixtures for component testing."""
 import pytest
 
+from homeassistant.components import zeroconf
+
 from tests.async_mock import patch
 
+zeroconf.orig_install_multiple_zeroconf_catcher = (
+    zeroconf.install_multiple_zeroconf_catcher
+)
+zeroconf.install_multiple_zeroconf_catcher = lambda zc: None
+
 
 @pytest.fixture(autouse=True)
 def prevent_io():

tests/components/zeroconf/conftest.py

@@ -0,0 +1,11 @@
+"""conftest for zeroconf."""
+import pytest
+
+from tests.async_mock import patch
+
+
+@pytest.fixture
+def mock_zeroconf():
+    """Mock zeroconf."""
+    with patch("homeassistant.components.zeroconf.HaZeroconf") as mock_zc:
+        yield mock_zc.return_value

tests/components/zeroconf/test_init.py

@@ -1,5 +1,4 @@
 """Test Zeroconf component setup process."""
-import pytest
 from zeroconf import InterfaceChoice, IPVersion, ServiceInfo, ServiceStateChange
 
 from homeassistant.components import zeroconf
@@ -22,13 +21,6 @@
 HOMEKIT_STATUS_PAIRED = b"0"
 
 
-@pytest.fixture
-def mock_zeroconf():
-    """Mock zeroconf."""
-    with patch("homeassistant.components.zeroconf.HaZeroconf") as mock_zc:
-        yield mock_zc.return_value
-
-
 def service_update_mock(zeroconf, services, handlers):
     """Call service update handler."""
     for service in services:

tests/components/zeroconf/test_usage.py

@@ -0,0 +1,56 @@
+"""Test Zeroconf multiple instance protection."""
+import zeroconf
+
+from homeassistant.components.zeroconf import async_get_instance
+from homeassistant.components.zeroconf.usage import install_multiple_zeroconf_catcher
+
+from tests.async_mock import Mock, patch
+
+
+async def test_multiple_zeroconf_instances(hass, mock_zeroconf, caplog):
+    """Test creating multiple zeroconf throws without an integration."""
+
+    zeroconf_instance = await async_get_instance(hass)
+
+    install_multiple_zeroconf_catcher(zeroconf_instance)
+
+    new_zeroconf_instance = zeroconf.Zeroconf()
+    assert new_zeroconf_instance == zeroconf_instance
+
+    assert "Zeroconf" in caplog.text
+
+
+async def test_multiple_zeroconf_instances_gives_shared(hass, mock_zeroconf, caplog):
+    """Test creating multiple zeroconf gives the shared instance to an integration."""
+
+    zeroconf_instance = await async_get_instance(hass)
+
+    install_multiple_zeroconf_catcher(zeroconf_instance)
+
+    correct_frame = Mock(
+        filename="/config/custom_components/burncpu/light.py",
+        lineno="23",
+        line="self.light.is_on",
+    )
+    with patch(
+        "homeassistant.helpers.frame.extract_stack",
+        return_value=[
+            Mock(
+                filename="/home/dev/homeassistant/core.py",
+                lineno="23",
+                line="do_something()",
+            ),
+            correct_frame,
+            Mock(
+                filename="/home/dev/homeassistant/components/zeroconf/usage.py",
+                lineno="23",
+                line="self.light.is_on",
+            ),
+            Mock(filename="/home/dev/mdns/lights.py", lineno="2", line="something()",),
+        ],
+    ):
+        assert zeroconf.Zeroconf() == zeroconf_instance
+
+    assert "custom_components/burncpu/light.py" in caplog.text
+    assert "23" in caplog.text
+    assert "self.light.is_on" in caplog.text

tests/helpers/test_frame.py

@@ -36,6 +36,39 @@ async def test_extract_frame_integration(caplog):
     assert found_frame == correct_frame
 
 
+async def test_extract_frame_integration_with_excluded_intergration(caplog):
+    """Test extracting the current frame from integration context."""
+    correct_frame = Mock(
+        filename="/home/dev/homeassistant/components/mdns/light.py",
+        lineno="23",
+        line="self.light.is_on",
+    )
+    with patch(
+        "homeassistant.helpers.frame.extract_stack",
+        return_value=[
+            Mock(
+                filename="/home/dev/homeassistant/core.py",
+                lineno="23",
+                line="do_something()",
+            ),
+            correct_frame,
+            Mock(
+                filename="/home/dev/homeassistant/components/zeroconf/usage.py",
+                lineno="23",
+                line="self.light.is_on",
+            ),
+            Mock(filename="/home/dev/mdns/lights.py", lineno="2", line="something()",),
+        ],
+    ):
+        found_frame, integration, path = frame.get_integration_frame(
+            exclude_integrations={"zeroconf"}
+        )
+
+    assert integration == "mdns"
+    assert path == "homeassistant/components/"
+    assert found_frame == correct_frame
+
+
 async def test_extract_frame_no_integration(caplog):
     """Test extracting the current frame without integration context."""
     with patch(