Merge branch 'issue_22269' into 'master'

Mattermost Notifications Service

## What does this MR do?
closes #22269 

## Screenshots 

![mattermost](/uploads/de71c121f544a91305b6dfa6dc4c5738/mattermost.png)  
![slack](/uploads/081d75d49239319d94332abda214fb98/slack.png)

## Does this MR meet the acceptance criteria?

- [x] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [x] API support added
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if it does - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)


See merge request !7764

39 files changed, 321 insertions, 133 deletions

diff --git a/app/models/project.rb b/app/models/project.rb
index 2c726cfc5df..5d092ca42c2 100644
--- a/app/models/project.rb
+++ b/app/models/project.rb
@@ -95,7 +95,8 @@ class Project < ActiveRecord::Base
   has_one :asana_service, dependent: :destroy
   has_one :gemnasium_service, dependent: :destroy
   has_one :mattermost_slash_commands_service, dependent: :destroy
-  has_one :slack_service, dependent: :destroy
+  has_one :mattermost_notification_service, dependent: :destroy
+  has_one :slack_notification_service, dependent: :destroy
   has_one :buildkite_service, dependent: :destroy
   has_one :bamboo_service, dependent: :destroy
   has_one :teamcity_service, dependent: :destroy
diff --git a/app/models/project_services/slack_service/base_message.rb b/app/models/project_services/chat_message/base_message.rb
index f1182824687..a03605d01fb 100644
--- a/app/models/project_services/slack_service/base_message.rb
+++ b/app/models/project_services/chat_message/base_message.rb
@@ -1,6 +1,6 @@
 require 'slack-notifier'
 
-class SlackService
+module ChatMessage
   class BaseMessage
     def initialize(params)
       raise NotImplementedError
diff --git a/app/models/project_services/slack_service/build_message.rb b/app/models/project_services/chat_message/build_message.rb
index 0fca4267bad..53e35cb21bf 100644
--- a/app/models/project_services/slack_service/build_message.rb
+++ b/app/models/project_services/chat_message/build_message.rb
@@ -1,4 +1,4 @@
-class SlackService
+module ChatMessage
   class BuildMessage < BaseMessage
     attr_reader :sha
     attr_reader :ref_type
diff --git a/app/models/project_services/slack_service/issue_message.rb b/app/models/project_services/chat_message/issue_message.rb
index cd87a79d0c6..14fd64e5332 100644
--- a/app/models/project_services/slack_service/issue_message.rb
+++ b/app/models/project_services/chat_message/issue_message.rb
@@ -1,4 +1,4 @@
-class SlackService
+module ChatMessage
   class IssueMessage < BaseMessage
     attr_reader :user_name
     attr_reader :title
diff --git a/app/models/project_services/slack_service/merge_message.rb b/app/models/project_services/chat_message/merge_message.rb
index b7615c96068..ab5e8b24167 100644
--- a/app/models/project_services/slack_service/merge_message.rb
+++ b/app/models/project_services/chat_message/merge_message.rb
@@ -1,4 +1,4 @@
-class SlackService
+module ChatMessage
   class MergeMessage < BaseMessage
     attr_reader :user_name
     attr_reader :project_name
diff --git a/app/models/project_services/slack_service/note_message.rb b/app/models/project_services/chat_message/note_message.rb
index 797c5937f09..ca1d7207034 100644
--- a/app/models/project_services/slack_service/note_message.rb
+++ b/app/models/project_services/chat_message/note_message.rb
@@ -1,4 +1,4 @@
-class SlackService
+module ChatMessage
   class NoteMessage < BaseMessage
     attr_reader :message
     attr_reader :user_name
diff --git a/app/models/project_services/slack_service/pipeline_message.rb b/app/models/project_services/chat_message/pipeline_message.rb
index b6355fc4171..210027565a8 100644
--- a/app/models/project_services/slack_service/pipeline_message.rb
+++ b/app/models/project_services/chat_message/pipeline_message.rb
@@ -1,4 +1,4 @@
-class SlackService
+module ChatMessage
   class PipelineMessage < BaseMessage
     attr_reader :ref_type, :ref, :status, :project_name, :project_url,
                 :user_name, :duration, :pipeline_id
diff --git a/app/models/project_services/slack_service/push_message.rb b/app/models/project_services/chat_message/push_message.rb
index b26f3e9ddce..2d73b71ec37 100644
--- a/app/models/project_services/slack_service/push_message.rb
+++ b/app/models/project_services/chat_message/push_message.rb
@@ -1,4 +1,4 @@
-class SlackService
+module ChatMessage
   class PushMessage < BaseMessage
     attr_reader :after
     attr_reader :before
diff --git a/app/models/project_services/slack_service/wiki_page_message.rb b/app/models/project_services/chat_message/wiki_page_message.rb
index 160ca3ac115..134083e4504 100644
--- a/app/models/project_services/slack_service/wiki_page_message.rb
+++ b/app/models/project_services/chat_message/wiki_page_message.rb
@@ -1,4 +1,4 @@
-class SlackService
+module ChatMessage
   class WikiPageMessage < BaseMessage
     attr_reader :user_name
     attr_reader :title
diff --git a/app/models/project_services/slack_service.rb b/app/models/project_services/chat_notification_service.rb
index e1b937817f4..b0556987721 100644
--- a/app/models/project_services/slack_service.rb
+++ b/app/models/project_services/chat_notification_service.rb
@@ -1,6 +1,13 @@
-class SlackService < Service
+# Base class for Chat notifications services
+# This class is not meant to be used directly, but only to inherit from.
+class ChatNotificationService < Service
+  include ChatMessage
+
+  default_value_for :category, 'chat'
+
   prop_accessor :webhook, :username, :channel
   boolean_accessor :notify_only_broken_builds, :notify_only_broken_pipelines
+
   validates :webhook, presence: true, url: true, if: :activated?
 
   def initialize_properties
@@ -14,35 +21,8 @@ class SlackService < Service
     end
   end
 
-  def title
-    'Slack'
-  end
-
-  def description
-    'A team communication tool for the 21st century'
-  end
-
-  def to_param
-    'slack'
-  end
-
-  def help
-    'This service sends notifications to your Slack channel.<br/>
-    To setup this Service you need to create a new <b>"Incoming webhook"</b> in your Slack integration panel,
-    and enter the Webhook URL below.'
-  end
-
-  def fields
-    default_fields =
-      [
-        { type: 'text', name: 'webhook',   placeholder: 'https://hooks.slack.com/services/...' },
-        { type: 'text', name: 'username', placeholder: 'username' },
-        { type: 'text', name: 'channel', placeholder: "#general" },
-        { type: 'checkbox', name: 'notify_only_broken_builds' },
-        { type: 'checkbox', name: 'notify_only_broken_pipelines' },
-      ]
-
-    default_fields + build_event_channels
+  def can_test?
+    valid?
   end
 
   def supported_events
@@ -67,21 +47,16 @@ class SlackService < Service
 
     message = get_message(object_kind, data)
 
-    if message
-      opt = {}
-
-      event_channel = get_channel_field(object_kind) || channel
+    return false unless message
 
-      opt[:channel] = event_channel if event_channel
-      opt[:username] = username if username
+    opt = {}
 
-      notifier = Slack::Notifier.new(webhook, opt)
-      notifier.ping(message.pretext, attachments: message.attachments, fallback: message.fallback)
+    opt[:channel]  = get_channel_field(object_kind).presence || channel || default_channel
+    opt[:username] = username if username
+    notifier = Slack::Notifier.new(webhook, opt)
+    notifier.ping(message.pretext, attachments: message.attachments, fallback: message.fallback)
 
-      true
-    else
-      false
-    end
+    true
   end
 
   def event_channel_names
@@ -96,6 +71,10 @@ class SlackService < Service
     fields.reject { |field| field[:name].end_with?('channel') }
   end
 
+  def default_channel
+    raise NotImplementedError
+  end
+
   private
 
   def get_message(object_kind, data)
@@ -124,7 +103,7 @@ class SlackService < Service
 
   def build_event_channels
     supported_events.reduce([]) do |channels, event|
-      channels << { type: 'text', name: event_channel_name(event), placeholder: "#general" }
+      channels << { type: 'text', name: event_channel_name(event), placeholder: default_channel }
     end
   end
 
@@ -166,11 +145,3 @@ class SlackService < Service
     end
   end
 end
-
-require "slack_service/issue_message"
-require "slack_service/push_message"
-require "slack_service/merge_message"
-require "slack_service/note_message"
-require "slack_service/build_message"
-require "slack_service/pipeline_message"
-require "slack_service/wiki_page_message"
diff --git a/app/models/project_services/chat_service.rb b/app/models/project_services/chat_service.rb
index d36beff5fa6..574788462de 100644
--- a/app/models/project_services/chat_service.rb
+++ b/app/models/project_services/chat_service.rb
@@ -1,5 +1,5 @@
 # Base class for Chat services
-# This class is not meant to be used directly, but only to inherrit from.
+# This class is not meant to be used directly, but only to inherit from.
 class ChatService < Service
   default_value_for :category, 'chat'
 
diff --git a/app/models/project_services/mattermost_notification_service.rb b/app/models/project_services/mattermost_notification_service.rb
new file mode 100644
index 00000000000..de18c4b1f00
--- /dev/null
+++ b/app/models/project_services/mattermost_notification_service.rb
@@ -0,0 +1,41 @@
+class MattermostNotificationService < ChatNotificationService
+  def title
+    'Mattermost notifications'
+  end
+
+  def description
+    'Receive event notifications in Mattermost'
+  end
+
+  def to_param
+    'mattermost_notification'
+  end
+
+  def help
+    'This service sends notifications about projects events to Mattermost channels.<br />
+    To set up this service:
+    <ol>
+      <li><a href="https://docs.mattermost.com/developer/webhooks-incoming.html#enabling-incoming-webhooks">Enable incoming webhooks</a> in your Mattermost installation. </li>
+      <li><a href="https://docs.mattermost.com/developer/webhooks-incoming.html#creating-integrations-using-incoming-webhooks">Add an incoming webhook</a> in your Mattermost team. The default channel can be overridden for each event. </li>
+      <li>Paste the webhook <strong>URL</strong> into the field bellow. </li>
+      <li>Select events below to enable notifications. The channel and username are optional. </li>
+    </ol>'
+  end
+
+  def fields
+    default_fields + build_event_channels
+  end
+
+  def default_fields
+    [
+      { type: 'text', name: 'webhook', placeholder: 'http://mattermost_host/hooks/...' },
+      { type: 'text', name: 'username', placeholder: 'username' },
+      { type: 'checkbox', name: 'notify_only_broken_builds' },
+      { type: 'checkbox', name: 'notify_only_broken_pipelines' },
+    ]
+  end
+
+  def default_channel
+    "#town-square"
+  end
+end
diff --git a/app/models/project_services/slack_notification_service.rb b/app/models/project_services/slack_notification_service.rb
new file mode 100644
index 00000000000..3cbf89efba4
--- /dev/null
+++ b/app/models/project_services/slack_notification_service.rb
@@ -0,0 +1,40 @@
+class SlackNotificationService < ChatNotificationService
+  def title
+    'Slack notifications'
+  end
+
+  def description
+    'Receive event notifications in Slack'
+  end
+
+  def to_param
+    'slack_notification'
+  end
+
+  def help
+    'This service sends notifications about projects events to Slack channels.<br />
+    To setup this service:
+    <ol>
+      <li><a href="https://slack.com/apps/A0F7XDUAZ-incoming-webhooks">Add an incoming webhook</a> in your Slack team. The default channel can be overridden for each event. </li>
+      <li>Paste the <strong>Webhook URL</strong> into the field below. </li>
+      <li>Select events below to enable notifications. The channel and username are optional. </li>
+    </ol>'
+  end
+
+  def fields
+    default_fields + build_event_channels
+  end
+
+  def default_fields
+    [
+      { type: 'text', name: 'webhook', placeholder: 'https://hooks.slack.com/services/...' },
+      { type: 'text', name: 'username', placeholder: 'username' },
+      { type: 'checkbox', name: 'notify_only_broken_builds' },
+      { type: 'checkbox', name: 'notify_only_broken_pipelines' },
+    ]
+  end
+
+  def default_channel
+    "#general"
+  end
+end
diff --git a/app/models/service.rb b/app/models/service.rb
index e49a8fa2904..0bbab078cf6 100644
--- a/app/models/service.rb
+++ b/app/models/service.rb
@@ -220,7 +220,8 @@ class Service < ActiveRecord::Base
       pivotaltracker
       pushover
       redmine
-      slack
+      mattermost_notification
+      slack_notification
       teamcity
     ]
   end
diff --git a/changelogs/unreleased/issue_22269.yml b/changelogs/unreleased/issue_22269.yml
new file mode 100644
index 00000000000..6b7164aff77
--- /dev/null
+++ b/changelogs/unreleased/issue_22269.yml
@@ -0,0 +1,4 @@
+---
+title: Create mattermost service
+merge_request: 
+author: 
diff --git a/db/migrate/20141006143943_move_slack_service_to_webhook.rb b/db/migrate/20141006143943_move_slack_service_to_webhook.rb
index 8cb120f7007..42e88d6d6e3 100644
--- a/db/migrate/20141006143943_move_slack_service_to_webhook.rb
+++ b/db/migrate/20141006143943_move_slack_service_to_webhook.rb
@@ -1,7 +1,11 @@
 # rubocop:disable all
 class MoveSlackServiceToWebhook < ActiveRecord::Migration
+
+  DOWNTIME = true
+  DOWNTIME_REASON = 'Move old fields "token" and "subdomain" to one single field "webhook"'
+
   def change
-    SlackService.all.each do |slack_service|
+    SlackNotificationService.all.each do |slack_service|
       if ["token", "subdomain"].all? { |property| slack_service.properties.key? property }
         token = slack_service.properties['token']
         subdomain = slack_service.properties['subdomain']
diff --git a/db/migrate/20161213172958_change_slack_service_to_slack_notification_service.rb b/db/migrate/20161213172958_change_slack_service_to_slack_notification_service.rb
new file mode 100644
index 00000000000..a7278d7b5a6
--- /dev/null
+++ b/db/migrate/20161213172958_change_slack_service_to_slack_notification_service.rb
@@ -0,0 +1,14 @@
+class ChangeSlackServiceToSlackNotificationService < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = true
+  DOWNTIME_REASON = 'Rename SlackService to SlackNotificationService'
+
+  def up
+    execute("UPDATE services SET type = 'SlackNotificationService' WHERE type = 'SlackService'")
+  end
+
+  def down
+    execute("UPDATE services SET type = 'SlackService' WHERE type = 'SlackNotificationService'")
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 67ff83d96d9..3786a41f9a9 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20161212142807) do
+ActiveRecord::Schema.define(version: 20161213172958) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
diff --git a/doc/api/services.md b/doc/api/services.md
index 3dad953cd1e..1466b8189b0 100644
--- a/doc/api/services.md
+++ b/doc/api/services.md
@@ -703,9 +703,9 @@ Get Redmine service settings for a project.
 GET /projects/:id/services/redmine
 ```
 
-## Slack
+## Slack notifications
 
-A team communication tool for the 21st century
+Receive event notifications in Slack
 
 ### Create/Edit Slack service
 
@@ -737,6 +737,40 @@ Get Slack service settings for a project.
 GET /projects/:id/services/slack
 ```
 
+## Mattermost notifications
+
+Receive event notifications in Mattermost
+
+### Create/Edit Mattermost notifications service
+
+Set Mattermost service for a project.
+
+```
+PUT /projects/:id/services/mattermost
+```
+
+Parameters:
+
+- `webhook` (**required**) - https://mattermost.example/hooks/1298aff...
+- `username` (optional) - username
+- `channel` (optional) - #channel
+
+### Delete Mattermost notifications service
+
+Delete Mattermost Notifications service for a project.
+
+```
+DELETE /projects/:id/services/mattermost
+```
+
+### Get Mattermost notifications service settings
+
+Get Mattermost notifications service settings for a project.
+
+```
+GET /projects/:id/services/mattermost
+```
+
 ## JetBrains TeamCity CI
 
 A continuous integration and build server
diff --git a/doc/project_services/img/mattermost_configuration.png b/doc/project_services/img/mattermost_configuration.png
new file mode 100644
index 00000000000..3c5ff5ee317
--- /dev/null
+++ b/doc/project_services/img/mattermost_configuration.png
diff --git a/doc/project_services/mattermost.md b/doc/project_services/mattermost.md
new file mode 100644
index 00000000000..fbc7dfeee6d
--- /dev/null
+++ b/doc/project_services/mattermost.md
@@ -0,0 +1,45 @@
+# Mattermost Notifications Service
+
+## On Mattermost
+
+To enable Mattermost integration you must create an incoming webhook integration:
+
+1. Sign in to your Mattermost instance
+1. Visit incoming webhooks, that will be something like: https://mattermost.example/your_team_name/integrations/incoming_webhooks/add
+1. Choose a display name, description and channel, those can be overridden on GitLab
+1. Save it, copy the **Webhook URL**, we'll need this later for GitLab.
+
+There might be some cases that Incoming Webhooks are blocked by admin, ask your mattermost admin to enable
+it on https://mattermost.example/admin_console/integrations/custom.
+
+Display name override is not enabled by default, you need to ask your admin to enable it on that same section.
+
+## On GitLab
+
+After you set up Mattermost, it's time to set up GitLab.
+
+Go to your project's **Settings > Services > Mattermost Notifications** and you will see a
+checkbox with the following events that can be triggered:
+
+- Push
+- Issue
+- Merge request
+- Note
+- Tag push
+- Build
+- Wiki page
+
+Bellow each of these event checkboxes, you will have an input field to insert
+which Mattermost channel you want to send that event message, with `#town-square`
+being the default. The hash sign is optional.
+
+At the end, fill in your Mattermost details:
+
+| Field | Description |
+| ----- | ----------- |
+| **Webhook**  | The incoming webhooks which you have to setup on Mattermost, it will be something like: http://mattermost.example/hooks/5xo... |
+| **Username** | Optional username which can be on messages sent to Mattermost. Fill this in if you want to change the username of the bot. |
+| **Notify only broken builds** | If you choose to enable the **Build** event and you want to be only notified about failed builds. |
+
+
+![Mattermost configuration](img/mattermost_configuration.png)
diff --git a/doc/project_services/project_services.md b/doc/project_services/project_services.md
index a7bcd186a8c..0f398874b8f 100644
--- a/doc/project_services/project_services.md
+++ b/doc/project_services/project_services.md
@@ -44,10 +44,11 @@ further configuration instructions and details. Contributions are welcome.
 | JetBrains TeamCity CI | A continuous integration and build server |
 | [Kubernetes](kubernetes.md) | A containerized deployment service |
 | [Mattermost slash commands](mattermost_slash_commands.md) | Mattermost chat and ChatOps slash commands |
+| [Mattermost Notifications](mattermost.md) | Receive event notifications in Mattermost |
+| [Slack Notifications](slack.md) | Receive event notifications in Slack |
 | PivotalTracker | Project Management Software (Source Commits Endpoint) |
 | Pushover | Pushover makes it easy to get real-time notifications on your Android device, iPhone, iPad, and Desktop |
 | [Redmine](redmine.md) | Redmine issue tracker |
-| [Slack](slack.md) | A team communication tool for the 21st century |
 
 ## Services Templates
 
diff --git a/doc/project_services/slack.md b/doc/project_services/slack.md
index 3cfe77c9f85..0b682b43810 100644
--- a/doc/project_services/slack.md
+++ b/doc/project_services/slack.md
@@ -1,4 +1,4 @@
-# Slack Service
+# Slack Notifications Service
 
 ## On Slack
 
@@ -15,7 +15,7 @@ Slack:
 
 After you set up Slack, it's time to set up GitLab.
 
-Go to your project's **Settings > Services > Slack** and you will see a
+Go to your project's **Settings > Services > Slack Notifications** and you will see a
 checkbox with the following events that can be triggered:
 
 - Push
diff --git a/lib/api/services.rb b/lib/api/services.rb
index b1e072b4f47..59232c84c24 100644
--- a/lib/api/services.rb
+++ b/lib/api/services.rb
@@ -473,7 +473,7 @@ module API
           desc: 'The description of the tracker'
         }
       ],
-      'slack' => [
+      'slack-notification' => [
         {
           required: true,
           name: :webhook,
@@ -493,6 +493,14 @@ module API
           desc: 'The channel name'
         }
       ],
+      'mattermost-notification' => [
+        {
+          required: true,
+          name: :webhook,
+          type: String,
+          desc: 'The Mattermost webhook. e.g. http://mattermost_host/hooks/...'
+        }
+      ],
       'teamcity' => [
         {
           required: true,
diff --git a/spec/features/projects/import_export/test_project_export.tar.gz b/spec/features/projects/import_export/test_project_export.tar.gz
index bfe59bdb90e..d3165d07d7b 100644
--- a/spec/features/projects/import_export/test_project_export.tar.gz
+++ b/spec/features/projects/import_export/test_project_export.tar.gz
diff --git a/spec/features/projects/services/slack_service_spec.rb b/spec/features/projects/services/slack_service_spec.rb
index 16541f51d98..320ed13a01d 100644
--- a/spec/features/projects/services/slack_service_spec.rb
+++ b/spec/features/projects/services/slack_service_spec.rb
@@ -2,8 +2,8 @@ require 'spec_helper'
 
 feature 'Projects > Slack service > Setup events', feature: true do
   let(:user) { create(:user) }
-  let(:service) { SlackService.new }
-  let(:project) { create(:project, slack_service: service) }
+  let(:service) { SlackNotificationService.new }
+  let(:project) { create(:project, slack_notification_service: service) }
 
   background do
     service.fields
diff --git a/spec/lib/gitlab/import_export/all_models.yml b/spec/lib/gitlab/import_export/all_models.yml
index c4ee838b7c9..9b49d6837c3 100644
--- a/spec/lib/gitlab/import_export/all_models.yml
+++ b/spec/lib/gitlab/import_export/all_models.yml
@@ -136,7 +136,8 @@ project:
 - assembla_service
 - asana_service
 - gemnasium_service
-- slack_service
+- slack_notification_service
+- mattermost_notification_service
 - buildkite_service
 - bamboo_service
 - teamcity_service
diff --git a/spec/models/project_services/slack_service/build_message_spec.rb b/spec/models/project_services/chat_message/build_message_spec.rb
index 452f4e2782c..b71d153f814 100644
--- a/spec/models/project_services/slack_service/build_message_spec.rb
+++ b/spec/models/project_services/chat_message/build_message_spec.rb
@@ -1,7 +1,7 @@
 require 'spec_helper'
 
-describe SlackService::BuildMessage do
-  subject { SlackService::BuildMessage.new(args) }
+describe ChatMessage::BuildMessage do
+  subject { described_class.new(args) }
 
   let(:args) do
     {
diff --git a/spec/models/project_services/slack_service/issue_message_spec.rb b/spec/models/project_services/chat_message/issue_message_spec.rb
index 98c36ec088d..ebe0ead4408 100644
--- a/spec/models/project_services/slack_service/issue_message_spec.rb
+++ b/spec/models/project_services/chat_message/issue_message_spec.rb
@@ -1,7 +1,7 @@
 require 'spec_helper'
 
-describe SlackService::IssueMessage, models: true do
-  subject { SlackService::IssueMessage.new(args) }
+describe ChatMessage::IssueMessage, models: true do
+  subject { described_class.new(args) }
 
   let(:args) do
     {
diff --git a/spec/models/project_services/slack_service/merge_message_spec.rb b/spec/models/project_services/chat_message/merge_message_spec.rb
index c5c052d9af1..07c414c6ca4 100644
--- a/spec/models/project_services/slack_service/merge_message_spec.rb
+++ b/spec/models/project_services/chat_message/merge_message_spec.rb
@@ -1,7 +1,7 @@
 require 'spec_helper'
 
-describe SlackService::MergeMessage, models: true do
-  subject { SlackService::MergeMessage.new(args) }
+describe ChatMessage::MergeMessage, models: true do
+  subject { described_class.new(args) }
 
   let(:args) do
     {
diff --git a/spec/models/project_services/slack_service/note_message_spec.rb b/spec/models/project_services/chat_message/note_message_spec.rb
index 97f818125d3..31936da40a2 100644
--- a/spec/models/project_services/slack_service/note_message_spec.rb
+++ b/spec/models/project_services/chat_message/note_message_spec.rb
@@ -1,6 +1,6 @@
 require 'spec_helper'
 
-describe SlackService::NoteMessage, models: true do
+describe ChatMessage::NoteMessage, models: true do
   let(:color) { '#345' }
 
   before do
@@ -36,7 +36,7 @@ describe SlackService::NoteMessage, models: true do
     end
 
     it 'returns a message regarding notes on commits' do
-      message = SlackService::NoteMessage.new(@args)
+      message = described_class.new(@args)
       expect(message.pretext).to eq("test.user <url|commented on " \
       "commit 5f163b2b> in <somewhere.com|project_name>: " \
       "*Added a commit message*")
@@ -62,7 +62,7 @@ describe SlackService::NoteMessage, models: true do
     end
 
     it 'returns a message regarding notes on a merge request' do
-      message = SlackService::NoteMessage.new(@args)
+      message = described_class.new(@args)
       expect(message.pretext).to eq("test.user <url|commented on " \
       "merge request !30> in <somewhere.com|project_name>: " \
       "*merge request title*")
@@ -88,7 +88,7 @@ describe SlackService::NoteMessage, models: true do
     end
 
     it 'returns a message regarding notes on an issue' do
-      message = SlackService::NoteMessage.new(@args)
+      message = described_class.new(@args)
       expect(message.pretext).to eq(
         "test.user <url|commented on " \
         "issue #20> in <somewhere.com|project_name>: " \
@@ -114,7 +114,7 @@ describe SlackService::NoteMessage, models: true do
     end
 
     it 'returns a message regarding notes on a project snippet' do
-      message = SlackService::NoteMessage.new(@args)
+      message = described_class.new(@args)
       expect(message.pretext).to eq("test.user <url|commented on " \
       "snippet #5> in <somewhere.com|project_name>: " \
       "*snippet title*")
diff --git a/spec/models/project_services/slack_service/pipeline_message_spec.rb b/spec/models/project_services/chat_message/pipeline_message_spec.rb
index 4098500122f..eca71db07b6 100644
--- a/spec/models/project_services/slack_service/pipeline_message_spec.rb
+++ b/spec/models/project_services/chat_message/pipeline_message_spec.rb
@@ -1,7 +1,7 @@
 require 'spec_helper'
 
-describe SlackService::PipelineMessage do
-  subject { SlackService::PipelineMessage.new(args) }
+describe ChatMessage::PipelineMessage do
+  subject { described_class.new(args) }
   let(:user) { { name: 'hacker' } }
 
   let(:args) do
diff --git a/spec/models/project_services/slack_service/push_message_spec.rb b/spec/models/project_services/chat_message/push_message_spec.rb
index 17cd05e24f1..b781c4505db 100644
--- a/spec/models/project_services/slack_service/push_message_spec.rb
+++ b/spec/models/project_services/chat_message/push_message_spec.rb
@@ -1,7 +1,7 @@
 require 'spec_helper'
 
-describe SlackService::PushMessage, models: true do
-  subject { SlackService::PushMessage.new(args) }
+describe ChatMessage::PushMessage, models: true do
+  subject { described_class.new(args) }
 
   let(:args) do
     {
diff --git a/spec/models/project_services/slack_service/wiki_page_message_spec.rb b/spec/models/project_services/chat_message/wiki_page_message_spec.rb
index 093911598b0..94c04dc0865 100644
--- a/spec/models/project_services/slack_service/wiki_page_message_spec.rb
+++ b/spec/models/project_services/chat_message/wiki_page_message_spec.rb
@@ -1,6 +1,6 @@
 require 'spec_helper'
 
-describe SlackService::WikiPageMessage, models: true do
+describe ChatMessage::WikiPageMessage, models: true do
   subject { described_class.new(args) }
 
   let(:args) do
diff --git a/spec/models/project_services/chat_notification_service_spec.rb b/spec/models/project_services/chat_notification_service_spec.rb
new file mode 100644
index 00000000000..c98e7ee14fd
--- /dev/null
+++ b/spec/models/project_services/chat_notification_service_spec.rb
@@ -0,0 +1,11 @@
+require 'spec_helper'
+
+describe ChatNotificationService, models: true do
+  describe "Associations" do
+    before do
+      allow(subject).to receive(:activated?).and_return(true)
+    end
+
+    it { is_expected.to validate_presence_of :webhook }
+  end
+end
diff --git a/spec/models/project_services/mattermost_notification_service_spec.rb b/spec/models/project_services/mattermost_notification_service_spec.rb
new file mode 100644
index 00000000000..c01e64b4c8e
--- /dev/null
+++ b/spec/models/project_services/mattermost_notification_service_spec.rb
@@ -0,0 +1,5 @@
+require 'spec_helper'
+
+describe MattermostNotificationService, models: true do
+  it_behaves_like "slack or mattermost"
+end
diff --git a/spec/models/project_services/slack_notification_service_spec.rb b/spec/models/project_services/slack_notification_service_spec.rb
new file mode 100644
index 00000000000..59ddddf7454
--- /dev/null
+++ b/spec/models/project_services/slack_notification_service_spec.rb
@@ -0,0 +1,5 @@
+require 'spec_helper'
+
+describe SlackNotificationService, models: true do
+  it_behaves_like "slack or mattermost"
+end
diff --git a/spec/models/project_spec.rb b/spec/models/project_spec.rb
index 21ff238841e..bab3c3dbb02 100644
--- a/spec/models/project_spec.rb
+++ b/spec/models/project_spec.rb
@@ -22,7 +22,8 @@ describe Project, models: true do
     it { is_expected.to have_many(:protected_branches).dependent(:destroy) }
     it { is_expected.to have_many(:chat_services) }
     it { is_expected.to have_one(:forked_project_link).dependent(:destroy) }
-    it { is_expected.to have_one(:slack_service).dependent(:destroy) }
+    it { is_expected.to have_one(:slack_notification_service).dependent(:destroy) }
+    it { is_expected.to have_one(:mattermost_notification_service).dependent(:destroy) }
     it { is_expected.to have_one(:pushover_service).dependent(:destroy) }
     it { is_expected.to have_one(:asana_service).dependent(:destroy) }
     it { is_expected.to have_many(:boards).dependent(:destroy) }
diff --git a/spec/models/project_services/slack_service_spec.rb b/spec/support/slack_mattermost_shared_examples.rb
index c07a70a8069..56d4965f74d 100644
--- a/spec/models/project_services/slack_service_spec.rb
+++ b/spec/support/slack_mattermost_shared_examples.rb
@@ -1,7 +1,7 @@
-require 'spec_helper'
+Dir[Rails.root.join("app/models/project_services/chat_message/*.rb")].each { |f| require f }
 
-describe SlackService, models: true do
-  let(:slack) { SlackService.new }
+RSpec.shared_examples 'slack or mattermost' do
+  let(:chat_service) { described_class.new }
   let(:webhook_url) { 'https://example.gitlab.com/' }
 
   describe "Associations" do
@@ -24,7 +24,7 @@ describe SlackService, models: true do
     end
   end
 
-  describe "Execute" do
+  describe "#execute" do
     let(:user)    { create(:user) }
     let(:project) { create(:project) }
     let(:username) { 'slack_username' }
@@ -35,7 +35,7 @@ describe SlackService, models: true do
     end
 
     before do
-      allow(slack).to receive_messages(
+      allow(chat_service).to receive_messages(
         project: project,
         project_id: project.id,
         service_hook: true,
@@ -77,54 +77,55 @@ describe SlackService, models: true do
       @wiki_page_sample_data = wiki_page_service.hook_data(@wiki_page, 'create')
     end
 
-    it "calls Slack API for push events" do
-      slack.execute(push_sample_data)
+    it "calls Slack/Mattermost API for push events" do
+      chat_service.execute(push_sample_data)
 
       expect(WebMock).to have_requested(:post, webhook_url).once
     end
 
-    it "calls Slack API for issue events" do
-      slack.execute(@issues_sample_data)
+    it "calls Slack/Mattermost API for issue events" do
+      chat_service.execute(@issues_sample_data)
 
       expect(WebMock).to have_requested(:post, webhook_url).once
     end
 
-    it "calls Slack API for merge requests events" do
-      slack.execute(@merge_sample_data)
+    it "calls Slack/Mattermost API for merge requests events" do
+      chat_service.execute(@merge_sample_data)
 
       expect(WebMock).to have_requested(:post, webhook_url).once
     end
 
-    it "calls Slack API for wiki page events" do
-      slack.execute(@wiki_page_sample_data)
+    it "calls Slack/Mattermost API for wiki page events" do
+      chat_service.execute(@wiki_page_sample_data)
 
       expect(WebMock).to have_requested(:post, webhook_url).once
     end
 
     it 'uses the username as an option for slack when configured' do
-      allow(slack).to receive(:username).and_return(username)
+      allow(chat_service).to receive(:username).and_return(username)
+
       expect(Slack::Notifier).to receive(:new).
-       with(webhook_url, username: username).
+       with(webhook_url, username: username, channel: chat_service.default_channel).
        and_return(
          double(:slack_service).as_null_object
        )
 
-      slack.execute(push_sample_data)
+      chat_service.execute(push_sample_data)
     end
 
     it 'uses the channel as an option when it is configured' do
-      allow(slack).to receive(:channel).and_return(channel)
+      allow(chat_service).to receive(:channel).and_return(channel)
       expect(Slack::Notifier).to receive(:new).
         with(webhook_url, channel: channel).
         and_return(
           double(:slack_service).as_null_object
         )
-      slack.execute(push_sample_data)
+      chat_service.execute(push_sample_data)
     end
 
     context "event channels" do
       it "uses the right channel for push event" do
-        slack.update_attributes(push_channel: "random")
+        chat_service.update_attributes(push_channel: "random")
 
         expect(Slack::Notifier).to receive(:new).
          with(webhook_url, channel: "random").
@@ -132,11 +133,11 @@ describe SlackService, models: true do
            double(:slack_service).as_null_object
          )
 
-        slack.execute(push_sample_data)
+        chat_service.execute(push_sample_data)
       end
 
       it "uses the right channel for merge request event" do
-        slack.update_attributes(merge_request_channel: "random")
+        chat_service.update_attributes(merge_request_channel: "random")
 
         expect(Slack::Notifier).to receive(:new).
          with(webhook_url, channel: "random").
@@ -144,11 +145,11 @@ describe SlackService, models: true do
            double(:slack_service).as_null_object
          )
 
-        slack.execute(@merge_sample_data)
+        chat_service.execute(@merge_sample_data)
       end
 
       it "uses the right channel for issue event" do
-        slack.update_attributes(issue_channel: "random")
+        chat_service.update_attributes(issue_channel: "random")
 
         expect(Slack::Notifier).to receive(:new).
          with(webhook_url, channel: "random").
@@ -156,11 +157,11 @@ describe SlackService, models: true do
            double(:slack_service).as_null_object
          )
 
-        slack.execute(@issues_sample_data)
+        chat_service.execute(@issues_sample_data)
       end
 
       it "uses the right channel for wiki event" do
-        slack.update_attributes(wiki_page_channel: "random")
+        chat_service.update_attributes(wiki_page_channel: "random")
 
         expect(Slack::Notifier).to receive(:new).
          with(webhook_url, channel: "random").
@@ -168,7 +169,7 @@ describe SlackService, models: true do
            double(:slack_service).as_null_object
          )
 
-        slack.execute(@wiki_page_sample_data)
+        chat_service.execute(@wiki_page_sample_data)
       end
 
       context "note event" do
@@ -177,7 +178,7 @@ describe SlackService, models: true do
         end
 
         it "uses the right channel" do
-          slack.update_attributes(note_channel: "random")
+          chat_service.update_attributes(note_channel: "random")
 
           note_data = Gitlab::DataBuilder::Note.build(issue_note, user)
 
@@ -187,7 +188,7 @@ describe SlackService, models: true do
              double(:slack_service).as_null_object
            )
 
-          slack.execute(note_data)
+          chat_service.execute(note_data)
         end
       end
     end
@@ -198,7 +199,7 @@ describe SlackService, models: true do
     let(:project) { create(:project, creator_id: user.id) }
 
     before do
-      allow(slack).to receive_messages(
+      allow(chat_service).to receive_messages(
         project: project,
         project_id: project.id,
         service_hook: true,
@@ -216,9 +217,9 @@ describe SlackService, models: true do
                                 note: 'a comment on a commit')
       end
 
-      it "calls Slack API for commit comment events" do
+      it "calls Slack/Mattermost API for commit comment events" do
         data = Gitlab::DataBuilder::Note.build(commit_note, user)
-        slack.execute(data)
+        chat_service.execute(data)
 
         expect(WebMock).to have_requested(:post, webhook_url).once
       end
@@ -232,7 +233,7 @@ describe SlackService, models: true do
 
       it "calls Slack API for merge request comment events" do
         data = Gitlab::DataBuilder::Note.build(merge_request_note, user)
-        slack.execute(data)
+        chat_service.execute(data)
 
         expect(WebMock).to have_requested(:post, webhook_url).once
       end
@@ -245,7 +246,7 @@ describe SlackService, models: true do
 
       it "calls Slack API for issue comment events" do
         data = Gitlab::DataBuilder::Note.build(issue_note, user)
-        slack.execute(data)
+        chat_service.execute(data)
 
         expect(WebMock).to have_requested(:post, webhook_url).once
       end
@@ -259,7 +260,7 @@ describe SlackService, models: true do
 
       it "calls Slack API for snippet comment events" do
         data = Gitlab::DataBuilder::Note.build(snippet_note, user)
-        slack.execute(data)
+        chat_service.execute(data)
 
         expect(WebMock).to have_requested(:post, webhook_url).once
       end
@@ -277,21 +278,21 @@ describe SlackService, models: true do
     end
 
     before do
-      allow(slack).to receive_messages(
+      allow(chat_service).to receive_messages(
         project: project,
         service_hook: true,
         webhook: webhook_url
       )
     end
 
-    shared_examples 'call Slack API' do
+    shared_examples 'call Slack/Mattermost API' do
       before do
         WebMock.stub_request(:post, webhook_url)
       end
 
-      it 'calls Slack API for pipeline events' do
+      it 'calls Slack/Mattermost API for pipeline events' do
         data = Gitlab::DataBuilder::Pipeline.build(pipeline)
-        slack.execute(data)
+        chat_service.execute(data)
 
         expect(WebMock).to have_requested(:post, webhook_url).once
       end
@@ -300,16 +301,16 @@ describe SlackService, models: true do
     context 'with failed pipeline' do
       let(:status) { 'failed' }
 
-      it_behaves_like 'call Slack API'
+      it_behaves_like 'call Slack/Mattermost API'
     end
 
     context 'with succeeded pipeline' do
       let(:status) { 'success' }
 
       context 'with default to notify_only_broken_pipelines' do
-        it 'does not call Slack API for pipeline events' do
+        it 'does not call Slack/Mattermost API for pipeline events' do
           data = Gitlab::DataBuilder::Pipeline.build(pipeline)
-          result = slack.execute(data)
+          result = chat_service.execute(data)
 
           expect(result).to be_falsy
         end
@@ -317,10 +318,10 @@ describe SlackService, models: true do
 
       context 'with setting notify_only_broken_pipelines to false' do
         before do
-          slack.notify_only_broken_pipelines = false
+          chat_service.notify_only_broken_pipelines = false
         end
 
-        it_behaves_like 'call Slack API'
+        it_behaves_like 'call Slack/Mattermost API'
       end
     end
   end