Introduce new ProjectCiCdSetting

app/models/project.rb

@@ -68,6 +68,11 @@ class Project < ActiveRecord::Base
 
   after_save :update_project_statistics, if: :namespace_id_changed?
   after_create :create_project_feature, unless: :project_feature
+
+  after_create :create_ci_cd_settings,
+    unless: :ci_cd_settings,
+    if: proc { ProjectCiCdSetting.available? }
+
   after_create :set_last_activity_at
   after_create :set_last_repository_updated_at
   after_update :update_forks_visibility_level
@@ -231,6 +236,7 @@ class Project < ActiveRecord::Base
   has_many :custom_attributes, class_name: 'ProjectCustomAttribute'
 
   has_many :project_badges, class_name: 'ProjectBadge'
+  has_one :ci_cd_settings, class_name: 'ProjectCiCdSetting'
 
   accepts_nested_attributes_for :variables, allow_destroy: true
   accepts_nested_attributes_for :project_feature, update_only: true

app/models/project_ci_cd_setting.rb

+class ProjectCiCdSetting < ActiveRecord::Base
+  belongs_to :project
+
+  # The version of the schema that first introduced this model/table.
+  MINIMUM_SCHEMA_VERSION = 20180403035759
+
+  def self.available?
+    @available ||=
+      ActiveRecord::Migrator.current_version >= MINIMUM_SCHEMA_VERSION
+  end
+
+  def self.reset_column_information
+    @available = nil
+    super
+  end
+end

changelogs/unreleased/10244-add-project-ci-cd-settings.yml

+---
+title: Introduce new ProjectCiCdSetting model with group_runners_enabled
+merge_request: 18144
+author:
+type: performance

db/migrate/20180403035759_create_project_ci_cd_settings.rb

+class CreateProjectCiCdSettings < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    unless table_exists?(:project_ci_cd_settings)
+      create_table(:project_ci_cd_settings) do |t|
+        t.integer(:project_id, null: false)
+        t.boolean(:group_runners_enabled, default: true, null: false)
+      end
+    end
+
+    disable_statement_timeout
+
+    # This particular INSERT will take between 10 and 20 seconds.
+    execute 'INSERT INTO project_ci_cd_settings (project_id) SELECT id FROM projects'
+
+    # We add the index and foreign key separately so the above INSERT statement
+    # takes as little time as possible.
+    add_concurrent_index(:project_ci_cd_settings, :project_id, unique: true)
+
+    add_foreign_key_with_retry
+  end
+
+  def down
+    drop_table :project_ci_cd_settings
+  end
+
+  def add_foreign_key_with_retry
+    if Gitlab::Database.mysql?
+      # When using MySQL we don't support online upgrades, thus projects can't
+      # be deleted while we are running this migration.
+      return add_project_id_foreign_key
+    end
+
+    # Between the initial INSERT and the addition of the foreign key some
+    # projects may have been removed, leaving orphaned rows in our new settings
+    # table.
+    loop do
+      remove_orphaned_settings
+
+      begin
+        add_project_id_foreign_key
+        break
+      rescue ActiveRecord::InvalidForeignKey
+        say 'project_ci_cd_settings contains some orphaned rows, retrying...'
+      end
+    end
+  end
+
+  def add_project_id_foreign_key
+    add_concurrent_foreign_key(:project_ci_cd_settings, :projects, column: :project_id)
+  end
+
+  def remove_orphaned_settings
+    execute <<~SQL
+      DELETE FROM project_ci_cd_settings
+      WHERE NOT EXISTS (
+        SELECT 1
+        FROM projects
+        WHERE projects.id = project_ci_cd_settings.project_id
+      )
+    SQL
+  end
+end

db/post_migrate/20180409170809_populate_missing_project_ci_cd_settings.rb

+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class PopulateMissingProjectCiCdSettings < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    # MySQL does not support online upgrades, thus there can't be any missing
+    # rows.
+    return if Gitlab::Database.mysql?
+
+    # Projects created after the initial migration but before the code started
+    # using ProjectCiCdSetting won't have a corresponding row in
+    # project_ci_cd_settings, so let's fix that.
+    execute <<~SQL
+      INSERT INTO project_ci_cd_settings (project_id)
+      SELECT id
+      FROM projects
+      WHERE NOT EXISTS (
+        SELECT 1
+        FROM project_ci_cd_settings
+        WHERE project_ci_cd_settings.project_id = projects.id
+      )
+    SQL
+  end
+
+  def down
+    # There's nothing to revert for this migration.
+  end
+end

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: 20180405142733) do
+ActiveRecord::Schema.define(version: 20180409170809) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -1432,6 +1432,13 @@ ActiveRecord::Schema.define(version: 20180405142733) do
 
   add_index "project_auto_devops", ["project_id"], name: "index_project_auto_devops_on_project_id", unique: true, using: :btree
 
+  create_table "project_ci_cd_settings", force: :cascade do |t|
+    t.integer "project_id", null: false
+    t.boolean "group_runners_enabled", default: true, null: false
+  end
+
+  add_index "project_ci_cd_settings", ["project_id"], name: "index_project_ci_cd_settings_on_project_id", unique: true, using: :btree
+
   create_table "project_custom_attributes", force: :cascade do |t|
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
@@ -2157,6 +2164,7 @@ ActiveRecord::Schema.define(version: 20180405142733) do
   add_foreign_key "project_authorizations", "projects", on_delete: :cascade
   add_foreign_key "project_authorizations", "users", on_delete: :cascade
   add_foreign_key "project_auto_devops", "projects", on_delete: :cascade
+  add_foreign_key "project_ci_cd_settings", "projects", name: "fk_24c15d2f2e", on_delete: :cascade
   add_foreign_key "project_custom_attributes", "projects", on_delete: :cascade
   add_foreign_key "project_deploy_tokens", "deploy_tokens", on_delete: :cascade
   add_foreign_key "project_deploy_tokens", "projects", on_delete: :cascade

lib/gitlab/import_export/import_export.yml

@@ -66,6 +66,7 @@ project_tree:
   - :project_feature
   - :custom_attributes
   - :project_badges
+  - :ci_cd_settings
 
 # Only include the following attributes for the models specified.
 included_attributes:
@@ -75,6 +76,8 @@ included_attributes:
     - :username
   author:
     - :name
+  ci_cd_settings:
+    - :group_runners_enabled
 
 # Do not include the following attributes for the models specified.
 excluded_attributes:

lib/gitlab/import_export/relation_factory.rb

@@ -17,7 +17,8 @@ module Gitlab
                     auto_devops: :project_auto_devops,
                     label: :project_label,
                     custom_attributes: 'ProjectCustomAttribute',
-                    project_badges: 'Badge' }.freeze
+                    project_badges: 'Badge',
+                    ci_cd_settings: 'ProjectCiCdSetting' }.freeze
 
       USER_REFERENCES = %w[author_id assignee_id updated_by_id user_id created_by_id last_edited_by_id merge_user_id resolved_by_id closed_by_id].freeze
 

spec/lib/gitlab/import_export/all_models.yml

@@ -286,6 +286,7 @@ project:
 - internal_ids
 - project_deploy_tokens
 - deploy_tokens
+- ci_cd_settings
 award_emoji:
 - awardable
 - user

spec/lib/gitlab/import_export/safe_model_attributes.yml

@@ -552,3 +552,5 @@ Badge:
 - created_at
 - updated_at
 - type
+ProjectCiCdSetting:
+- group_runners_enabled

spec/models/project_ci_cd_setting_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe ProjectCiCdSetting do
+  describe '.available?' do
+    before do
+      described_class.reset_column_information
+    end
+
+    it 'returns true' do
+      expect(described_class).to be_available
+    end
+
+    it 'memoizes the schema version' do
+      expect(ActiveRecord::Migrator)
+        .to receive(:current_version)
+        .and_call_original
+        .once
+
+      2.times { described_class.available? }
+    end
+  end
+end

spec/models/project_spec.rb

@@ -93,6 +93,15 @@ describe Project do
       end
     end
 
+    context 'when creating a new project' do
+      it 'automatically creates a CI/CD settings row' do
+        project = create(:project)
+
+        expect(project.ci_cd_settings).to be_an_instance_of(ProjectCiCdSetting)
+        expect(project.ci_cd_settings).to be_persisted
+      end
+    end
+
     describe '#members & #requesters' do
       let(:project) { create(:project, :public, :access_requestable) }
       let(:requester) { create(:user) }