How can I debug e-mail sending on Gitlab? - ruby-on-rails

Question

My Gitlab (version 5) is not sending any e-mails and I am lost trying to figure out what is happening. The logs give no useful information. I configured it to used sendmail.
I wrote a small script that sends e-mail through ActionMailer (I guess it is what gitlab uses to send e-mail, right?). And it sends the e-mail correctly.
But, on my Gitlab, I can guarantee that sendmail is not even being called.
Do I need to enable something to get e-mail notifications? How can I debug my issue?
Update
The problem is that I can not find any information anywhere. The thing just fails silently. Where can I find some kind of log? The logs in the log dir provide no useful information.
My question is, how can I make Gitlab be more verbose? How can I make it tell me what is going on?
Update 2
I just found a lot of mails scheduled on the Background jobs section. A lot of unprocessed Sidekiq::Extensions::DelayedMailer. What does it mean? Why were these jobs not processed?

Answer 1

Stumbled upon this issue today, here's my research:
Debugging SMTP connections in the GitLab GUI is not supported yet. However there is a pending feature request and a command line solution.
Set the desired SMTP settings /etc/gitlab/gitlab.rb and run gitlab-ctl reconfigure (see https://docs.gitlab.com/omnibus/settings/smtp.html).
Start the console running gitlab-rails console -e production.
Show the configured delivery method (should be :smtp) running the command ActionMailer::Base.delivery_method. Show all configured SMTP settings running ActionMailer::Base.smtp_settings.
To send a test mail run
Notify.test_email('youremail#example.com', 'Hello World', 'This is a test message').deliver_now
On the admin page in GitLab, the section »Background jobs« shows information about all jobs. Failing SMTP connections are listed there as well.
Please note, you may need to restart the GitLab instance in order to use the newly configured SMTP settings (on my instance the console was able to send mails, the GUI required a restart). Run gitlab-ctl restart to restart your instance.

Answer 2

First, I will tell what was my problem: The sidekiq is responsible for handling sending e-mails. For some reason my sidekiq was stuck, restarting it solved the problem.
Where I found information about problems I found on Gitlab:
The logs dir. It has a few informations.
On admin page, the section "Background jobs" gives information about the sidekiq.
The javascript console (if your browser supports it) also has useful information. Only if your problem is related to javascript.
And if you reach this point, you may modify Gitlab's code so you can "trace it" writing to a file:
File.open('/tmp/logfile','a') { |file| file.write("Hello World!\n") }

Answer 3

Maybe try enabling delivery errors in production mode and see what happens
config.action_mailer.raise_delivery_errors = true

Answer 4

I had the same problem and found that I needed to mod application.rb:
diff --git a/config/application.rb b/config/application.rb
index d85bcab..274976f 100644
--- a/config/application.rb
+++ b/config/application.rb
## -11,6 +11,8 ## end
module Gitlab
class Application < Rails::Application
+ config.action_mailer.sendmail_settings = { :arguments => "-i" }
+
# Settings in config/environments/* take precedence over those specified here.
# Application configuration should go into files in config/initializers
# -- all .rb files in that directory are automatically loaded.
Note: I'm running Debian 7 which uses exim for mail.

Answer 5

In the admin section under Background Jobs if you have lots of items in the Scheduled tab try restarting sidekiq:
cd /home/git/gitlab
exec rake sidekiq:start RAILS_ENV=production