automatic: allow use of STARTTLS/TLS

Add the ability to use STARTTLS/TLS for sending e-mail via the `email`
emitter.

The `email_tls` option supports three settings: ``starttls``, used to
switch to TLS on plaintext ports like 25 or 587 and ``yes``, used to
wrap the entire connection in TLS, usually on port 465. Any other
setting (``off`` by default) will use plain unencrypted SMTP.

Note: this depends on #1956 .

= changelog =
msg: Add `email_tls` option to DNF Automatic
type: enhancement
resolves: #1954

dnf/automatic/emitter.py

@@ -96,6 +96,7 @@ def commit(self):
  email_from = self._conf.email_from
  email_to = self._conf.email_to
  email_port = self._conf.email_port
+ email_tls = self._conf.email_tls
  message['Date'] = email.utils.formatdate()
  message['From'] = email_from
  message['Subject'] = subj
@@ -104,7 +105,12 @@ def commit(self):
 
  # Send the email
  try:
- smtp = smtplib.SMTP(self._conf.email_host, self._conf.email_port, timeout=300)
+ if self._conf.email_tls == 'yes':
+ smtp = smtplib.SMTP_SSL(self._conf.email_host, self._conf.email_port, timeout=300)
+ else:
+ smtp = smtplib.SMTP(self._conf.email_host, self._conf.email_port, timeout=300)
+ if self._conf.email_tls == 'starttls':
+ smtp.starttls()
  smtp.sendmail(email_from, email_to, message.as_string())
  smtp.close()
  except OSError as exc:

dnf/automatic/main.py

@@ -198,6 +198,7 @@ def __init__(self):
  self.add_option('email_from', libdnf.conf.OptionString("root"))
  self.add_option('email_host', libdnf.conf.OptionString("localhost"))
  self.add_option('email_port', libdnf.conf.OptionNumberInt32(25))
+ self.add_option('email_tls', libdnf.conf.OptionString("no"))
 
 
 class CommandConfig(Config):