Merge branch '39895-cant-set-mattermost-username-channel-from-api' into 'master'

Fix acceptance of username for Mattermost service update

Closes #39895

See merge request gitlab-org/gitlab-ce!15275

1 files changed, 6 insertions, 0 deletions

diff --git a/lib/api/services.rb b/lib/api/services.rb
index 6454e475036..bbcc851d07a 100644
--- a/lib/api/services.rb
+++ b/lib/api/services.rb
@@ -522,6 +522,12 @@ module API
           name: :webhook,
           type: String,
           desc: 'The Mattermost webhook. e.g. http://mattermost_host/hooks/...'
+        },
+        {
+          required: false,
+          name: :username,
+          type: String,
+          desc: 'The username to use to post the message'
         }
       ],
       'teamcity' => [