Merge branch '14669-bugzilla-integration' into 'master'

Bugzilla Integration

## What does this MR do?
Adds Bugzilla as a project service for external issue tracking

## Are there points in the code the reviewer needs to double check?

## Why was this MR needed?
Provides a notable Bugzilla option for use as an external issue tracker.  Existing Custom Issue tracker can be used to setup Bugzilla but this makes it clear that Bugzilla is an option.

## What are the relevant issue numbers?
Closes #14669

## Screenshots (if relevant)

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [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 you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)


See merge request !4930

9 files changed, 97 insertions, 4 deletions

diff --git a/CHANGELOG b/CHANGELOG
index fdd437deee7..c27ad4a4676 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -18,6 +18,7 @@ v 8.10.0 (unreleased)
   - Check for conflicts with existing Project's wiki path when creating a new project.
   - Remove unused front-end variable -> default_issues_tracker
   - Add API endpoint for a group issues !4520 (mahcsig)
+  - Add Bugzilla integration !4930 (iamtjg)
   - Allow [ci skip] to be in any case and allow [skip ci]. !4785 (simon_w)
   - Add basic system information like memory and disk usage to the admin panel
 
diff --git a/app/models/project.rb b/app/models/project.rb
index 96837364423..73ded09c162 100644
--- a/app/models/project.rb
+++ b/app/models/project.rb
@@ -81,6 +81,7 @@ class Project < ActiveRecord::Base
   has_one :jira_service, dependent: :destroy
   has_one :redmine_service, dependent: :destroy
   has_one :custom_issue_tracker_service, dependent: :destroy
+  has_one :bugzilla_service, dependent: :destroy
   has_one :gitlab_issue_tracker_service, dependent: :destroy, inverse_of: :project
   has_one :external_wiki_service, dependent: :destroy
 
diff --git a/app/models/project_services/bugzilla_service.rb b/app/models/project_services/bugzilla_service.rb
new file mode 100644
index 00000000000..260f6030957
--- /dev/null
+++ b/app/models/project_services/bugzilla_service.rb
@@ -0,0 +1,25 @@
+class BugzillaService < IssueTrackerService
+
+  prop_accessor :title, :description, :project_url, :issues_url, :new_issue_url
+
+  def title
+    if self.properties && self.properties['title'].present?
+      self.properties['title']
+    else
+      'Bugzilla'
+    end
+  end
+
+  def description
+    if self.properties && self.properties['description'].present?
+      self.properties['description']
+    else
+      'Bugzilla issue tracker'
+    end
+  end
+
+  def to_param
+    'bugzilla'
+  end
+
+end
diff --git a/app/models/project_services/custom_issue_tracker_service.rb b/app/models/project_services/custom_issue_tracker_service.rb
index 6b2b1daa724..8f2db46a7ba 100644
--- a/app/models/project_services/custom_issue_tracker_service.rb
+++ b/app/models/project_services/custom_issue_tracker_service.rb
@@ -32,7 +32,4 @@ class CustomIssueTrackerService < IssueTrackerService
     ]
   end
 
-  def initialize_properties
-    self.properties = {} if properties.nil?
-  end
 end
diff --git a/app/models/service.rb b/app/models/service.rb
index 40d39933ad8..d7a32c28267 100644
--- a/app/models/service.rb
+++ b/app/models/service.rb
@@ -170,6 +170,7 @@ class Service < ActiveRecord::Base
       bamboo
       buildkite
       builds_email
+      bugzilla
       campfire
       custom_issue_tracker
       drone_ci
diff --git a/doc/integration/external-issue-tracker.md b/doc/integration/external-issue-tracker.md
index a2d7e922aad..8d2c6351fb8 100644
--- a/doc/integration/external-issue-tracker.md
+++ b/doc/integration/external-issue-tracker.md
@@ -1,7 +1,7 @@
 # External issue tracker
 
 GitLab has a great issue tracker but you can also use an external one such as
-Jira or Redmine. Issue trackers are configurable per GitLab project and allow
+Jira, Redmine, or Bugzilla. Issue trackers are configurable per GitLab project and allow
 you to do the following:
 
 - the **Issues** link on the GitLab project pages takes you to the appropriate
@@ -20,6 +20,7 @@ Visit the links below for details:
 
 - [Redmine](../project_services/redmine.md)
 - [Jira](../project_services/jira.md)
+- [Bugzilla](../project_services/bugzilla.md)
 
 ### Service Template
 
diff --git a/doc/project_services/bugzilla.md b/doc/project_services/bugzilla.md
new file mode 100644
index 00000000000..215ed6fe9cc
--- /dev/null
+++ b/doc/project_services/bugzilla.md
@@ -0,0 +1,17 @@
+# Bugzilla Service
+
+Go to your project's **Settings > Services > Bugzilla** and fill in the required
+details as described in the table below.
+
+| Field | Description |
+| ----- | ----------- |
+| `description`   | A name for the issue tracker (to differentiate between instances, for example) |
+| `project_url`   | The URL to the project in Bugzilla which is being linked to this GitLab project. Note that the `project_url` requires PRODUCT_NAME to be updated with the product/project name in Bugzilla. |
+| `issues_url`    | The URL to the issue in Bugzilla project that is linked to this GitLab project. Note that the `issues_url` requires `:id` in the URL. This ID is used by GitLab as a placeholder to replace the issue number. |
+| `new_issue_url` | This is the URL to create a new issue in Bugzilla for the project linked to this GitLab project. Note that the `new_issue_url` requires PRODUCT_NAME to be updated with the product/project name in Bugzilla. |
+
+Once you have configured and enabled Bugzilla:
+
+- the **Issues** link on the GitLab project pages takes you to the appropriate
+  Bugzilla product page
+- clicking **New issue** on the project dashboard takes you to Bugzilla for entering a new issue
diff --git a/doc/project_services/project_services.md b/doc/project_services/project_services.md
index f81a035f70b..e15d5db3253 100644
--- a/doc/project_services/project_services.md
+++ b/doc/project_services/project_services.md
@@ -30,6 +30,7 @@ further configuration instructions and details. Contributions are welcome.
 | [Atlassian Bamboo CI](bamboo.md) | A continuous integration and build server |
 | Buildkite | Continuous integration and deployments |
 | [Builds emails](builds_emails.md) |	Email the builds status to a list of recipients |
+| [Bugzilla](bugzilla.md) | Bugzilla issue tracker |
 | Campfire | Simple web-based real-time group chat |
 | Custom Issue Tracker | Custom issue tracker |
 | Drone CI | Continuous Integration platform built on Docker, written in Go |
diff --git a/spec/models/project_services/bugzilla_service_spec.rb b/spec/models/project_services/bugzilla_service_spec.rb
new file mode 100644
index 00000000000..a6d9717ccb5
--- /dev/null
+++ b/spec/models/project_services/bugzilla_service_spec.rb
@@ -0,0 +1,49 @@
+# == Schema Information
+#
+# Table name: services
+#
+#  id                    :integer          not null, primary key
+#  type                  :string(255)
+#  title                 :string(255)
+#  project_id            :integer
+#  created_at            :datetime
+#  updated_at            :datetime
+#  active                :boolean          default(FALSE), not null
+#  properties            :text
+#  template              :boolean          default(FALSE)
+#  push_events           :boolean          default(TRUE)
+#  issues_events         :boolean          default(TRUE)
+#  merge_requests_events :boolean          default(TRUE)
+#  tag_push_events       :boolean          default(TRUE)
+#  note_events           :boolean          default(TRUE), not null
+#
+
+require 'spec_helper'
+
+describe BugzillaService, models: true do
+  describe 'Associations' do
+    it { is_expected.to belong_to :project }
+    it { is_expected.to have_one :service_hook }
+  end
+
+  describe 'Validations' do
+    context 'when service is active' do
+      before { subject.active = true }
+
+      it { is_expected.to validate_presence_of(:project_url) }
+      it { is_expected.to validate_presence_of(:issues_url) }
+      it { is_expected.to validate_presence_of(:new_issue_url) }
+      it_behaves_like 'issue tracker service URL attribute', :project_url
+      it_behaves_like 'issue tracker service URL attribute', :issues_url
+      it_behaves_like 'issue tracker service URL attribute', :new_issue_url
+    end
+
+    context 'when service is inactive' do
+      before { subject.active = false }
+
+      it { is_expected.not_to validate_presence_of(:project_url) }
+      it { is_expected.not_to validate_presence_of(:issues_url) }
+      it { is_expected.not_to validate_presence_of(:new_issue_url) }
+    end
+  end
+end