Local mDNS lookup failed for names published by other local containers

[joostlek]

The problem

I have my Mealie integration set up using the homeassistant.local URL (as it is running as an addon). When trying to start Mealie I get the following:

This error originated from a custom integration.

Logger: custom_components.mealie
Source: custom_components/mealie/__init__.py:52
integration: Mealie
First occurred: 15:14:02 (25 occurrences)
Last logged: 15:47:08

yes
Traceback (most recent call last):
  File "/usr/local/lib/python3.13/site-packages/aiohttp/connector.py", line 1351, in _create_direct_connection
    hosts = await self._resolve_host(host, port, traces=traces)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.13/site-packages/aiohttp/connector.py", line 995, in _resolve_host
    return await asyncio.shield(resolved_host_task)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.13/site-packages/aiohttp/connector.py", line 1026, in _resolve_host_with_throttle
    addrs = await self._resolver.resolve(host, port, family=self._family)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.13/site-packages/aiohttp_asyncmdnsresolver/_impl.py", line 94, in resolve
    return await self._resolve_mdns(host, port, family)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.13/site-packages/aiohttp_asyncmdnsresolver/_impl.py", line 116, in _resolve_mdns
    raise OSError(None, "MDNS lookup failed")
OSError: [Errno None] MDNS lookup failed

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/usr/local/lib/python3.13/site-packages/aiomealie/mealie.py", line 87, in _request
    response = await self.session.request(
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^
        method, url, headers=headers, params=params, json=data
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/usr/local/lib/python3.13/site-packages/aiohttp/client.py", line 703, in _request
    conn = await self._connector.connect(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        req, traces=traces, timeout=real_timeout
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/usr/local/lib/python3.13/site-packages/aiohttp/connector.py", line 548, in connect
    proto = await self._create_connection(req, traces, timeout)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.13/site-packages/aiohttp/connector.py", line 1056, in _create_connection
    _, proto = await self._create_direct_connection(req, traces, timeout)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.13/site-packages/aiohttp/connector.py", line 1357, in _create_direct_connection
    raise ClientConnectorDNSError(req.connection_key, exc) from exc
aiohttp.client_exceptions.ClientConnectorDNSError: Cannot connect to host homeassistant.local:9090 ssl:default [MDNS lookup failed]

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/config/custom_components/mealie/__init__.py", line 52, in async_setup_entry
    about = await client.get_about()
            ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.13/site-packages/aiomealie/mealie.py", line 199, in get_about
    response = await self._get("api/app/about")
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.13/site-packages/aiomealie/mealie.py", line 139, in _get
    return await self._request(METH_GET, uri, params=params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.13/site-packages/aiomealie/mealie.py", line 95, in _request
    raise MealieConnectionError(msg) from exception
aiomealie.exceptions.MealieConnectionError: Client connection error while connecting to Mealie

(I installed mealie as custom component as this wasn't originally logged)

What version of Home Assistant Core has the issue?

core-2025.2.0b1

What was the last working version of Home Assistant Core?

core-2025.1.4

What type of installation are you running?

Home Assistant OS

Integration causing the issue

zeroconf

Link to integration documentation on our website

https://www.home-assistant.io/integrations/zeroconf/

Diagnostics information

No response

Example YAML snippet

Anything in the logs that might be useful for us?

Additional information

No response

[home-assistant]

Hey there @bdraco, mind taking a look at this issue as it has been labeled with an integration (zeroconf) you are listed as a code owner for? Thanks!

Code owner commands

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• @home-assistant close Closes the issue.
• @home-assistant rename Awesome new title Renames the issue.
• @home-assistant reopen Reopen the issue.
• @home-assistant unassign zeroconf Removes the current integration label and assignees on the issue, add the integration domain after the command.
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[bdraco]

@joostlek would you please include debug logs for zeroconf from around the time the query fails ?

[bdraco]

It appears there is no response from the dns container when querying homeassistant.local. via mDNS, it only responds via normal DNS, which is why it worked before.

[davidmonro]

I'm seeing what I suspect is the same issue running under kubernetes - it appears that with this change, names ending in .local are only looked up in MDNS and not DNS; this breaks looking up k8s service names inside the cluster.

[ChromoX]

I'm seeing what I suspect is the same issue running under kubernetes - it appears that with this change, names ending in .local are only looked up in MDNS and not DNS; this breaks looking up k8s service names inside the cluster.

I'm seeing the same thing. Disabling zeroconf in the configuration.yaml doesn't seem to fix anything.

[bdraco]

We are only doing mDNS queries for .local domains now over aiohttp. Its a bit unexpected that .local domains are published via standard DNS. However this issue is about communication of mDNS traffic between containers so its not the place to discuss that change.

[davidmonro]

We are only doing mDNS queries for .local domains now over aiohttp. Its a bit unexpected that .local domains are published via standard DNS. However this issue is about communication of mDNS traffic between containers so its not the place to discuss that change.

Where should we discuss it then?

[bdraco]

We are only doing mDNS queries for .local domains now over aiohttp. Its a bit unexpected that .local domains are published via standard DNS. However this issue is about communication of mDNS traffic between containers so its not the place to discuss that change.

Where should we discuss it then?

Please make a new issue to discuss your specific use case.

[ChromoX]

I've made an issue specifically for the Kubernetes/Container .local (m)DNS resolution issues. #137478

[davidmonro]

raised an issue here: #137479