Mattermost Notifications Not Appearing / Being Sent

Summary

Admin Mattermost Notifications Service Template is not working with Gitlab when on separate servers.

Steps to reproduce

  1. Install Mattermost via Gitlab Omnibus on CentOS on two different servers both using TLS.
  2. Create Gitlab Activity channel in Mattermost
  3. Create a new incoming webhook within Mattermost linking to Gitlab Activity
  4. Navigate to Admin Area > Service Templates > Mattermost notifications and configure the web hook.
  5. Go to a project and test the settings, no message will be passed

What is the current bug behavior?

The test is run but no message is seen in Mattermost. Manually testing the incoming webhook works as expected.

What is the expected correct behavior?

A message about the activity should be received.

Relevant logs and/or screenshots

Unsure what aspect of things this should be in the logs for but:

screen-shot-2017-08-09-at-5.28.58-pm

screen-shot-2017-08-09-at-5.29.01-pm

screen-shot-2017-08-09-at-5.33.29-pm

screen-shot-2017-08-09-at-5.29.10-pm

Output of checks

What checks?

Results of GitLab environment info

Expand for output related to GitLab environment info 
Source:
System information
System:
Current User:	git
Using RVM:	no
Ruby Version:	2.3.3p222
Gem Version:	2.6.6
Bundler Version:1.13.7
Rake Version:	10.5.0
Redis Version:	3.2.5
Git Version:	2.13.0
Sidekiq Version:5.0.0
Go Version:	unknown


GitLab information
Version:	9.4.3
Revision:	b125d21
Directory:	/opt/gitlab/embedded/service/gitlab-rails
DB Adapter:	postgresql
URL:		https://pdcncs-sc01.REMOVED.com
HTTP Clone URL:	https://pdcncs-sc01.REMOVED.com/some-group/some-project.git
SSH Clone URL:	git@pdcncs-sc01.REMOVED.com:some-group/some-project.git
Using LDAP:	no
Using Omniauth:	no


GitLab Shell
Version:	5.3.1
Repository storage paths:
  • default: /var/opt/gitlab/git-data/repositories Hooks: /opt/gitlab/embedded/service/gitlab-shell/hooks Git: /opt/gitlab/embedded/bin/git

Destination: Not applicable as it's a Mattermost only installation of Gitlab

Results of GitLab application Check

Expand for output related to the GitLab application check 
Checking GitLab Shell ...

GitLab Shell version >= 5.3.1 ? ... OK (5.3.1)
Repo base directory exists?
default... yes
Repo storage directories are symlinks?
default... no
Repo paths owned by git:root, or git:git?
default... yes
Repo paths access is drwxrws---?
default... yes
hooks directories in repos are links: ...
2/1 ... ok
2/2 ... ok
39/3 ... ok
4/4 ... ok
4/5 ... ok
28/6 ... ok
28/7 ... ok
29/9 ... ok
40/10 ... ok
28/11 ... ok
5/12 ... ok
28/13 ... ok
28/14 ... ok
17/15 ... ok
17/16 ... ok
28/17 ... ok
5/18 ... ok
28/19 ... ok
4/20 ... ok
4/21 ... repository is empty
5/22 ... ok
5/23 ... ok
16/24 ... repository is empty
26/26 ... ok
41/27 ... repository is empty
62/28 ... ok
58/31 ... ok
17/32 ... ok
9/33 ... ok
9/34 ... ok
6/35 ... ok
4/36 ... ok
4/37 ... ok
4/38 ... ok
4/39 ... ok
60/40 ... ok
60/41 ... ok
58/42 ... ok
65/44 ... ok
5/46 ... ok
71/47 ... ok
65/48 ... ok
65/49 ... ok
65/50 ... ok
65/51 ... ok
17/52 ... ok
25/54 ... ok
25/55 ... ok
25/56 ... ok
6/57 ... ok
6/58 ... ok
58/59 ... ok
63/60 ... ok
63/61 ... ok
63/62 ... ok
59/63 ... ok
59/64 ... ok
17/65 ... ok
65/66 ... ok
6/67 ... ok
58/68 ... ok
67/69 ... ok
67/70 ... ok
67/71 ... ok
67/72 ... ok
67/73 ... ok
68/74 ... ok
59/75 ... ok
2/76 ... ok
2/77 ... ok
2/78 ... ok
2/79 ... ok
2/80 ... ok
69/82 ... ok
69/83 ... ok
59/84 ... ok
71/85 ... ok
69/86 ... ok
Running /opt/gitlab/embedded/service/gitlab-shell/bin/check
Check GitLab API access: OK
Access to /var/opt/gitlab/.ssh/authorized_keys: OK
Send ping to redis server: OK
gitlab-shell self-check successful


Checking GitLab Shell ... Finished


Checking Sidekiq ...


Running? ... yes
Number of Sidekiq processes ... 1


Checking Sidekiq ... Finished


Checking Reply by email ...


Reply by email is disabled in config/gitlab.yml


Checking Reply by email ... Finished


Checking LDAP ...


LDAP is disabled in config/gitlab.yml


Checking LDAP ... Finished


Checking GitLab ...


Git configured correctly? ... yes
Database config exists? ... yes
All migrations up? ... yes
Database contains orphaned GroupMembers? ... no
GitLab config exists? ... yes
GitLab config up to date? ... yes
Log directory writable? ... yes
Tmp directory writable? ... yes
Uploads directory exists? ... yes
Uploads directory has correct permissions? ... yes
Uploads directory tmp has correct permissions? ... yes
Init script exists? ... skipped (omnibus-gitlab has no init script)
Init script up-to-date? ... skipped (omnibus-gitlab has no init script)
Projects have namespace: ...
2/1 ... yes
2/2 ... yes
39/3 ... yes
4/4 ... yes
4/5 ... yes
28/6 ... yes
28/7 ... yes
29/9 ... yes
40/10 ... yes
28/11 ... yes
5/12 ... yes
28/13 ... yes
28/14 ... yes
17/15 ... yes
17/16 ... yes
28/17 ... yes
5/18 ... yes
28/19 ... yes
4/20 ... yes
4/21 ... yes
5/22 ... yes
5/23 ... yes
16/24 ... yes
26/26 ... yes
41/27 ... yes
62/28 ... yes
58/31 ... yes
17/32 ... yes
9/33 ... yes
9/34 ... yes
6/35 ... yes
4/36 ... yes
4/37 ... yes
4/38 ... yes
4/39 ... yes
60/40 ... yes
60/41 ... yes
58/42 ... yes
65/44 ... yes
5/46 ... yes
71/47 ... yes
65/48 ... yes
65/49 ... yes
65/50 ... yes
65/51 ... yes
17/52 ... yes
25/54 ... yes
25/55 ... yes
25/56 ... yes
6/57 ... yes
6/58 ... yes
58/59 ... yes
63/60 ... yes
63/61 ... yes
63/62 ... yes
59/63 ... yes
59/64 ... yes
17/65 ... yes
65/66 ... yes
6/67 ... yes
58/68 ... yes
67/69 ... yes
67/70 ... yes
67/71 ... yes
67/72 ... yes
67/73 ... yes
68/74 ... yes
59/75 ... yes
2/76 ... yes
2/77 ... yes
2/78 ... yes
2/79 ... yes
2/80 ... yes
69/82 ... yes
69/83 ... yes
59/84 ... yes
71/85 ... yes
69/86 ... yes
Redis version >= 2.8.0? ... yes
Ruby version >= 2.3.3 ? ... yes (2.3.3)
Git version >= 2.7.3 ? ... yes (2.13.0)
Active users: ... 44


Checking GitLab ... Finished

Possible fixes

Unknown