Backport CI service refactoring from EE

It allows easier contribution of different CI services
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/controllers/projects/merge_requests_controller.rb

@@ -160,7 +160,7 @@ class Projects::MergeRequestsController < Projects::ApplicationController
   end
 
   def ci_status
-    status = @merge_request.source_project.gitlab_ci_service.commit_status(merge_request.last_commit.sha)
+    status = @merge_request.source_project.ci_service.commit_status(merge_request.last_commit.sha)
     response = {status: status}
 
     render json: response

app/helpers/merge_requests_helper.rb

@@ -32,7 +32,7 @@ module MergeRequestsHelper
   end
 
   def ci_build_details_path merge_request
-    merge_request.source_project.gitlab_ci_service.build_page(merge_request.last_commit.sha)
+    merge_request.source_project.ci_service.build_page(merge_request.last_commit.sha)
   end
 
   def merge_path_description(merge_request, separator)

app/models/project.rb

@@ -54,6 +54,9 @@ class Project < ActiveRecord::Base
   belongs_to :namespace
 
   has_one :last_event, -> {order 'events.created_at DESC'}, class_name: 'Event', foreign_key: 'project_id'
+
+  # Project services
+  has_many :services
   has_one :gitlab_ci_service, dependent: :destroy
   has_one :campfire_service, dependent: :destroy
   has_one :emails_on_push_service, dependent: :destroy
@@ -322,6 +325,14 @@ class Project < ActiveRecord::Base
     gitlab_ci_service && gitlab_ci_service.active
   end
 
+  def ci_services
+    services.select { |service| service.category == :ci }
+  end
+
+  def ci_service
+    @ci_service ||= services.select(&:activated?).first
+  end
+
   # For compatibility with old code
   def code
     path

app/models/project_services/ci_service.rb

+# Base class for CI services
+# List methods you need to implement to get your CI service
+# working with GitLab Merge Requests
+class CiService < Service
+  def category
+    :ci
+  end
+
+  # Return complete url to build page
+  #
+  # Ex.
+  #   http://jenkins.example.com:8888/job/test1/scm/bySHA1/12d65c
+  #
+  def build_page(sha)
+    # implement inside child
+  end
+
+  # Return string with build status or :error symbol
+  #
+  # Allowed states: 'success', 'failed', 'running', 'pending'
+  #
+  #
+  # Ex.
+  #   @service.commit_status('13be4ac')
+  #   # => 'success'
+  #
+  #   @service.commit_status('2abe4ac')
+  #   # => 'running'
+  #
+  #
+  def commit_status(sha)
+    # implement inside child
+  end
+end

app/models/project_services/gitlab_ci_service.rb

@@ -17,7 +17,7 @@
 #  api_key     :string(255)
 #
 
-class GitlabCiService < Service
+class GitlabCiService < CiService
   attr_accessible :project_url
 
   validates :project_url, presence: true, if: :activated?

app/models/service.rb

@@ -33,6 +33,10 @@ class Service < ActiveRecord::Base
     active
   end
 
+  def category
+    :common
+  end
+
   def title
     # implement inside child
   end
@@ -41,6 +45,10 @@ class Service < ActiveRecord::Base
     # implement inside child
   end
 
+  def help
+    # implement inside child
+  end
+
   def to_param
     # implement inside child
   end

app/views/projects/merge_requests/_show.html.haml

@@ -40,7 +40,7 @@
     url_to_automerge_check: "#{automerge_check_project_merge_request_path(@project, @merge_request)}",
     check_enable: #{@merge_request.unchecked? ? "true" : "false"},
     url_to_ci_check: "#{ci_status_project_merge_request_path(@project, @merge_request)}",
-    ci_enable: #{@project.gitlab_ci? ? "true" : "false"},
+    ci_enable: #{@project.ci_service ? "true" : "false"},
     current_status: "#{@merge_request.merge_status_name}",
     action: "#{controller.action_name}"
   });

app/views/projects/merge_requests/show/_state_widget.html.haml

 .panel.mr-state-widget.panel-default
-  - if @merge_request.source_project.gitlab_ci? && @commits.any?
+  - if @merge_request.source_project.ci_service && @commits.any?
     .panel-heading
       = render "projects/merge_requests/show/mr_ci"
   .panel-body

app/views/projects/services/_form.html.haml

@@ -17,6 +17,9 @@
         - @service.errors.full_messages.each do |msg|
           %li= msg
 
+   - if @service.help.present?
+     .bs-callout
+       = @service.help
 
   .form-group
     = f.label :active, "Active", class: "control-label"