Allow system users to send mails from IPv6 localhost.

[orhtej2]

The problem

As observed in FitTrackee system user was not able to send mail. I narrowed it down to the following stanza(s)

manifest.toml:

[resources]
    [resources.system_user]
    allow_email = true

sample.py:

import smtplib
import ssl

sender_email = "[email protected]"
username = "system_user"
password = "password"
host = "domain.tld"
port = 25
recipient = "[email protected]"

message = "From: %s\r\nTo: %s\r\n\r\nTest message" % (sender_email, recipient)

print(message)

connection_params = {}
context = ssl.create_default_context()

with smtplib.SMTP(
  host, port, **connection_params
) as smtp:
  smtp.set_debuglevel(2)
  smtp.ehlo()
  smtp.starttls(context=context)
  smtp.ehlo()
  smtp.login(username, password)
  smtp.sendmail(sender_email, recipient, message)
  smtp.quit()

journalctl would indicate SMTP AUTH error for connection coming from localhost[::1].

Solution

As per documentation on allow_nets dovecot password file property one should add IPv6's localhost aka ::1 as well as local to allowed domains to allow connections in IPv6 environment as well as auth in no-IP scenarios (whatever these are).

PR Status

This is the piece of code that powers yunohost tools regen-conf, right?

Resulting change tested, hopefully it generates dovecot configuration as expected.

How to test

Relevant Python stanza provided, test with any provisioned system user with e-mail capabilities.

[orhtej2]

(Python code heavily inspired by FitTrackee's e-mail system: https://github.com/SamR1/FitTrackee/blob/master/fittrackee/emails/email.py)

[Thovi98]

Thank you @orhtej2 for your help and the fix 🎉