Send emails from a container in gitlab ci - docker

Question

I am using a openSUSE Tumbleweed container in a gitlab ci pipeline which runs some script. In that script, I need to send an email at some point of time with certain content.
In the container, I am installing postfix and configuring that relay server in /etc/postfix/main.cf.
The following command works on my laptop using that same relay server:
echo "This is the body of the email" | mail -s "This is the subject" -r sender#email.com receiver#email.com
but doesn't work from the container, even having the same postfix configuration.
I've seen some tutorials that show how to use the postfix/smtp configuration from the host, but since this is a container running in gitlab ci, that's not applicable.

Answer 1

So, finally opted for a python solution and call the script from bash, this way I really don't need to configure postfix, smtp or any other thing. You just export your variables in bash (our use argparse) and run this script. Of course, you need a relay server without auth (normally on port 25).
import os
import smtplib
from email.mime.text import MIMEText
smtp_server = os.environ.get('RELAY_SERVER')
port = os.environ.get('RELAY_PORT')
sender_email = os.environ.get('SENDER_EMAIL')
receiver_email = os.environ.get('RECEIVER_EMAIL')
mimetext = MIMEText("this is the body of the email")
mimetext['Subject'] = "this is the subject of the email"
mimetext['From'] = sender_email
mimetext['To'] = receiver_email
server = smtplib.SMTP(smtp_server, port)
server.ehlo()
server.sendmail(sender_email, receiver_email.split(','), mimetext.as_string())