Email notification attempt results in "[Errno 99] Cannot assign requested address".

[devEricA-zz]

Bug description
Whenever an email is attempted to be sent for a notification purpose, an alert pops up with this error.

Steps to reproduce

1. Go to 'Notifications' (under Configuration tab)
2. Check the 'Product Added' checkbox under the 'Mail' Column, and hit submit
3. Click on the dropdown where it says 'Scope', change to 'Global', and repeat step 2.
4. Click on 'System Settings' (under Configuration tab)
5. Check the box where it says 'Enable Mail Notifications'
6. Input one of your email addresses in the textbox where it says 'Mail Notifications to'.
7. Click on submit
8. Click on Add Product (under Products tab)
9. Fill out all of the required fields, and hit submit.
10. Notice that the alert count has gone up. One of them says "Notification Issue"
11. Click on the alerts tab, then click "See All alerts"
12. Observe the "Notification issue", description should read "[Errno 99] Cannot assign requested address"

Expected behavior
An email would be sent detailing the creation of a new product.

Deployment method (select with an X)

• Kubernetes
• Docker
• setup.bash / legacy-setup.bash

Environment information

• Operating System: Ubuntu 18.04
• DefectDojo version: 98ccfa0: Tweaks for 1339 [2019-07-22 13:22:40 -0500]

Additional context (optional)
Discovered while working on an overhaul for Defectdojo's notifications. Unsure if a specific email address is supposed to go into the "Email Notifications from" field, or if there is something wrong with the functionality of the email notifications.

[madchap]

So I didn't get that for the longest time, and now I do as well. That's on today's dev.

[madchap]

To reproduce, docker exec into the uwsgi container and run the following:

I have no name!@1a17c7a8976a:/app$ python
Python 3.5.7 (default, Jul 13 2019, 15:36:33) 
[GCC 8.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from django.core.mail import send_mail
>>> from django.conf import settings
>>> settings.configure()
>>> send_mail('test','test msg','fred@xxxxx.net',['fred@yyyyy.com'])
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.5/site-packages/django/core/mail/__init__.py", line 60, in send_mail
    return mail.send()
  File "/usr/local/lib/python3.5/site-packages/django/core/mail/message.py", line 291, in send
    return self.get_connection(fail_silently).send_messages([self])
  File "/usr/local/lib/python3.5/site-packages/django/core/mail/backends/smtp.py", line 103, in send_messages
    new_conn_created = self.open()
  File "/usr/local/lib/python3.5/site-packages/django/core/mail/backends/smtp.py", line 63, in open
    self.connection = self.connection_class(self.host, self.port, **connection_params)
  File "/usr/local/lib/python3.5/smtplib.py", line 251, in __init__
    (code, msg) = self.connect(host, port)
  File "/usr/local/lib/python3.5/smtplib.py", line 336, in connect
    self.sock = self._get_socket(host, port, self.timeout)
  File "/usr/local/lib/python3.5/smtplib.py", line 307, in _get_socket
    self.source_address)
  File "/usr/local/lib/python3.5/socket.py", line 712, in create_connection
    raise err
  File "/usr/local/lib/python3.5/socket.py", line 703, in create_connection
    sock.connect(sa)
OSError: [Errno 99] Cannot assign requested address

[madchap]

Another (and yes, the host running django sends email properly (i.e. I get daily O/S notifications), and is listening on 0.0.0.0:25)

I still need to restart the server (and hence this stack) to fully disable ipv6.. I guess it's known that sometimes this throws things off?

I have no name!@1a17c7a8976a:/app/dojo/settings$ python
Python 3.5.7 (default, Jul 13 2019, 15:36:33) 
[GCC 8.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import smtplib
>>> server = smtplib.SMTP("localhost:25")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.5/smtplib.py", line 251, in __init__
    (code, msg) = self.connect(host, port)
  File "/usr/local/lib/python3.5/smtplib.py", line 336, in connect
    self.sock = self._get_socket(host, port, self.timeout)
  File "/usr/local/lib/python3.5/smtplib.py", line 307, in _get_socket
    self.source_address)
  File "/usr/local/lib/python3.5/socket.py", line 712, in create_connection
    raise err
  File "/usr/local/lib/python3.5/socket.py", line 703, in create_connection
    sock.connect(sa)
OSError: [Errno 99] Cannot assign requested address

Using 127.0.0.1 has the same effect.

[madchap]

Disabled ipv6, stopped dojo, restarted docker daemon, restarted dojo, same thing.

[madchap]

I updated DD_EMAIL_URL to point to the IP address of the host as per the docker bridge interface (e.g. smtp://172.49.0.1:25).

From the container, I can connect and send an email using python console smptlib directly.

However, it still does not work using the dojo settings. Same error... or I am missing something?
I am missing something, no DD_* vars then.

[madchap]

OK, works better using python manage.py shell.. django n00b.

Of course, since the host changes and is not localhost anymore, don't forget to adjust your config to allow relaying.

Works now for me (tm).

[madchap]

So, not a bug I would say, configuration issue.

[madchap]

Closing here, no activity and likely in the end a configuration issue due to some change in docker -- at least, that's what happened to me.

Feel free to re-open @devEricA if you think I closed this wrongly.

Cheers.