python error on initial deploy: AttributeError: 'NoneType' object has no attribute 'split'

[Simon-Laux]

• Server OS (Operating System) - preferably Debian 12: debian 11 bullseye
• On which OS you run cmdeploy: nixos
• chatmail/relay version: 96108bb

Expected behavior

deploy sucessfully

Actual behavior

got an error

Logs

scripts/cmdeploy run
[ssh] login to chat.neochat.de
** WARNING: connection is not using a post-quantum key exchange algorithm.
** This session may be vulnerable to "store now, decrypt later" attacks.
** The server may need to be upgraded. See https://openssh.com/pq.html
[ssh] Collecting initial DNS settings.
............Traceback (most recent call last):
  File "/home/user/relay/venv/bin/cmdeploy", line 7, in <module>
    sys.exit(main())
             ~~~~^^
  File "/home/user/relay/cmdeploy/src/cmdeploy/cmdeploy.py", line 406, in main
    res = args.func(args, out, **kwargs)
  File "/home/user/relay/cmdeploy/src/cmdeploy/cmdeploy.py", line 90, in run_cmd
    remote_data = dns.get_initial_remote_data(sshexec, args.config.mail_domain)
  File "/home/user/relay/cmdeploy/src/cmdeploy/dns.py", line 10, in get_initial_remote_data
    return sshexec.logged(
           ~~~~~~~~~~~~~~^
        call=remote.rdns.perform_initial_checks, kwargs=dict(mail_domain=mail_domain)
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/home/user/relay/cmdeploy/src/cmdeploy/sshexec.py", line 79, in logged
    return self(call, kwargs, log_callback=print_stderr)
  File "/home/user/relay/cmdeploy/src/cmdeploy/sshexec.py", line 71, in __call__
    raise self.FuncError(data)
cmdeploy.sshexec.FuncError: Traceback (most recent call last):
  File "/root/from-cmdeploy/remote/_sshexec_bootstrap.py", line 18, in _handle_one_request
    res = func(**kwargs)
  File "/root/from-cmdeploy/remote/rdns.py", line 40, in perform_initial_checks
    parts = query_dns("TXT", f"_mta-sts.{mail_domain}").split("id=")
AttributeError: 'NoneType' object has no attribute 'split'

[Simon-Laux]

Maybe debian 11 bullseye is too old? either way it would make sense if the error would be handled and shown to the user in more friendly error message

[Simon-Laux]

Upgraded my VPS to debian 12 and still run into the same issue

[Simon-Laux]

IDE shows some type errors, maybe it would be a good idea to add a CI check for strict type checking in order to avoid such errors in the future?

[Simon-Laux]

I'm following the guide on https://chatmail.at/doc/relay/getting_started.html#setup-with-scripts-cmdeploy:

maybe step 1 of setting the dns entries is wrong?
It tell me to add a the following CNAME key:

mta-sts.chat.example.com. 3600 IN CNAME chat.example.com.

but the deploy script expects that a corresponding TXT key exists.
I guess this key is created later during setup, but I can't do the setup because it is missing. sounds like a "chicken and egg"-problem.