Problem with ipv6?! (Name or service not known)

[egabosh]

Moin,

Unfortunately, I get the following message on servers that are only accessible via IPv6, so I assume that Matrix Commander has a problem with IPv6.
Can you confirm this and fix it?

# docker run -t -v ./matrix-commander-data:/data:rw  matrixcommander/matrix-commander  --joined-rooms --output text --debug
2025-09-15 11:44:42,324:    DEBUG: matrix-commander: Debug is turned on. debug count=1
2025-09-15 11:44:42,324:    DEBUG: matrix-commander: Separator is set to "    " of length 4. E.g. Col1    Col2.
2025-09-15 11:44:42,324:    DEBUG: matrix-commander: Encryption is always enabled. It cannot be turned off. Use --tail to disable it for specific use cases.
2025-09-15 11:44:42,324:    DEBUG: matrix-commander: Option --sync is set to full.
2025-09-15 11:44:42,324:    DEBUG: matrix-commander: All arguments are valid. All checks passed.
2025-09-15 11:44:42,434:    DEBUG: matrix-commander: Create directory /root/.run for PID file.
2025-09-15 11:44:42,434:    DEBUG: matrix-commander: Trying to create a PID file to store process id 1.
2025-09-15 11:44:42,434:    DEBUG: matrix-commander: Successfully created PID file "/root/.run/matrix-commander.1515ab64-a820-4c8e-9d3d-3bd39efc69ae.pid" to store process id 1.
2025-09-15 11:44:42,434:    DEBUG: matrix-commander: Python version is "3.11.6 (main, Oct  3 2023, 00:00:00) [GCC 12.3.1 20230508 (Red Hat 12.3.1-1)]"
2025-09-15 11:44:42,434:    DEBUG: matrix-commander: Stdin pipe is assigned to "none".
2025-09-15 11:44:42,434:    DEBUG: matrix-commander: SSL will be used. Default SSL certificate validation will be done for this connection.
2025-09-15 11:44:42,435:    DEBUG: matrix-commander: Credentials file existed. So this is the one we suggest to use. file: /data/credentials.json
2025-09-15 11:44:42,436:    DEBUG: matrix-commander: Found an existing store in directory "/data/store" (local or arguments). It will be used.
2025-09-15 11:44:42,436:    DEBUG: matrix-commander: Starting to read credentials file.
2025-09-15 11:44:42,437:    DEBUG: matrix-commander: Finished reading credentials file.
2025-09-15 11:44:42,437:    DEBUG: matrix-commander: About to configure Matrix Async Client.
2025-09-15 11:44:42,437:    DEBUG: matrix-commander: About to initialize Matrix Async Client.
2025-09-15 11:44:42,437:    DEBUG: matrix-commander: About to restore login.
2025-09-15 11:44:42,461:    DEBUG: matrix-commander: Finished restoring login.
2025-09-15 11:44:42,461:    DEBUG: matrix-commander: Login will be using stored credentials from credentials file "/data/credentials.json". room_id = #MYHOST.MYDOMAIN:matrix.MYHOST.MYDOMAIN, device_id = BPMROLRAGZ, access_token = s***k.
2025-09-15 11:44:42,461:    DEBUG: matrix-commander: About to connect to server to verify connection.
2025-09-15 11:44:42,534:    ERROR: matrix-commander: E248: The program matrix-commander.py failed. Sorry.
2025-09-15 11:44:42,534:    DEBUG: matrix-commander: Cleanup: cleaning up.
2025-09-15 11:44:42,542:    ERROR: matrix-commander: Cannot connect to host matrix.MYHOST.MYDOMAIN:443 ssl:default [Name or service not known]
Here is the traceback.
Traceback (most recent call last):
  File "/usr/local/lib64/python3.11/site-packages/aiohttp/connector.py", line 1512, in _create_direct_connection
    hosts = await self._resolve_host(host, port, traces=traces)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib64/python3.11/site-packages/aiohttp/connector.py", line 1128, in _resolve_host
    return await asyncio.shield(resolved_host_task)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib64/python3.11/site-packages/aiohttp/connector.py", line 1159, in _resolve_host_with_throttle
    addrs = await self._resolver.resolve(host, port, family=self._family)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib64/python3.11/site-packages/aiohttp/resolver.py", line 40, in resolve
    infos = await self._loop.getaddrinfo(
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/python3.11/asyncio/base_events.py", line 867, in getaddrinfo
    return await self.run_in_executor(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/python3.11/concurrent/futures/thread.py", line 58, in run
    result = self.fn(*self.args, **self.kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/python3.11/socket.py", line 962, in getaddrinfo
    for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
socket.gaierror: [Errno -2] Name or service not known

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

Traceback (most recent call last):
  File "/app/matrix_commander/matrix_commander.py", line 10285, in main
    main_inner(argv)
  File "/app/matrix_commander/matrix_commander.py", line 10234, in main_inner
    asyncio.run(async_main())  # do everything in the event loop
    ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/python3.11/asyncio/runners.py", line 190, in run
    return runner.run(main)
           ^^^^^^^^^^^^^^^^
  File "/usr/lib64/python3.11/asyncio/runners.py", line 118, in run
    return self._loop.run_until_complete(task)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/python3.11/asyncio/base_events.py", line 653, in run_until_complete
    return future.result()
           ^^^^^^^^^^^^^^^
  File "/app/matrix_commander/matrix_commander.py", line 7229, in async_main
    await implicit_login()
  File "/app/matrix_commander/matrix_commander.py", line 7195, in implicit_login
    client, credentials = await login_using_credentials_file()
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/matrix_commander/matrix_commander.py", line 3997, in login_using_credentials_file
    raise (e)
  File "/app/matrix_commander/matrix_commander.py", line 3992, in login_using_credentials_file
    resp = await client.whoami()
           ^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/nio/client/async_client.py", line 3617, in whoami
    return await self._send(WhoamiResponse, method, path)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/nio/client/async_client.py", line 834, in _send
    transport_resp = await self.send(
                     ^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/nio/client/async_client.py", line 307, in wrapper
    return await func(self, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/nio/client/async_client.py", line 912, in send
    return await self.client_session.request(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib64/python3.11/site-packages/aiohttp/client.py", line 770, in _request
    resp = await handler(req)
           ^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib64/python3.11/site-packages/aiohttp/client.py", line 725, in _connect_and_send_request
    conn = await self._connector.connect(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/nio/client/async_client.py", line 281, in connect_wrapper
    connection = await type(self).connect(self, *args, **kwargs)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib64/python3.11/site-packages/aiohttp/connector.py", line 622, in connect
    proto = await self._create_connection(req, traces, timeout)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib64/python3.11/site-packages/aiohttp/connector.py", line 1189, in _create_connection
    _, proto = await self._create_direct_connection(req, traces, timeout)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib64/python3.11/site-packages/aiohttp/connector.py", line 1518, in _create_direct_connection
    raise ClientConnectorDNSError(req.connection_key, exc) from exc
aiohttp.client_exceptions.ClientConnectorDNSError: Cannot connect to host matrix.MYHOST.MYDOMAIN:443 ssl:default [Name or service not known]

2025-09-15 11:44:42,544:     INFO: matrix-commander: 2 errors and 0 warnings occurred.

Workaround on the same machine is to use /etc/hosts with local IPv4 IP and run container with -v /etc/hosts:/etc/hosts:ro
Then it works but only in local setups with IPv4.

Thank you
olli