Add database table and model for incident settings

These settings will be managed via the settings operation controller.

db/schema.rb

@@ -2284,6 +2284,12 @@ ActiveRecord::Schema.define(version: 20190228092516) do
     t.index ["project_id"], name: "index_project_import_data_on_project_id", using: :btree
   end
 
+  create_table "project_incident_management_settings", primary_key: "project_id", id: :integer, force: :cascade do |t|
+    t.boolean "create_issue", default: false, null: false
+    t.boolean "send_email", default: true, null: false
+    t.text "issue_template_key"
+  end
+
   create_table "project_mirror_data", force: :cascade do |t|
     t.integer "project_id", null: false
     t.integer "retry_count", default: 0, null: false
@@ -3512,6 +3518,7 @@ ActiveRecord::Schema.define(version: 20190228092516) do
   add_foreign_key "project_features", "projects", name: "fk_18513d9b92", on_delete: :cascade
   add_foreign_key "project_group_links", "projects", name: "fk_daa8cee94c", on_delete: :cascade
   add_foreign_key "project_import_data", "projects", name: "fk_ffb9ee3a10", on_delete: :cascade
+  add_foreign_key "project_incident_management_settings", "projects", on_delete: :cascade
   add_foreign_key "project_mirror_data", "projects", name: "fk_d1aad367d7", on_delete: :cascade
   add_foreign_key "project_repositories", "projects", on_delete: :cascade
   add_foreign_key "project_repositories", "shards", on_delete: :restrict

ee/app/models/ee/project.rb

@@ -41,6 +41,7 @@ module EE
       has_one :gitlab_slack_application_service
       has_one :tracing_setting, class_name: 'ProjectTracingSetting'
       has_one :alerting_setting, inverse_of: :project, class_name: 'Alerting::ProjectAlertingSetting'
+      has_one :incident_management_setting, inverse_of: :project, class_name: 'IncidentManagement::ProjectIncidentManagementSetting'
       has_one :feature_usage, class_name: 'ProjectFeatureUsage'
 
       has_many :reviews, inverse_of: :project

ee/app/models/incident_management/project_incident_management_setting.rb

+# frozen_string_literal: true
+
+module IncidentManagement
+  class ProjectIncidentManagementSetting < ApplicationRecord
+    belongs_to :project
+
+    validate :issue_template_exists, if: :create_issue?
+
+    private
+
+    def issue_template_exists
+      return unless issue_template_key.present?
+
+      Gitlab::Template::IssueTemplate.find(issue_template_key, project)
+    rescue Gitlab::Template::Finders::RepoTemplateFinder::FileNotFoundError
+      errors.add(:issue_template_key, 'not found')
+    end
+  end
+end

ee/db/migrate/20190226154144_create_project_incident_management_settings.rb

+# frozen_string_literal: true
+
+class CreateProjectIncidentManagementSettings < ActiveRecord::Migration[5.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  def change
+    create_table :project_incident_management_settings, id: :int, primary_key: :project_id do |t|
+      t.boolean :create_issue, default: false, null: false
+      t.boolean :send_email, default: true, null: false
+      t.text :issue_template_key
+      t.foreign_key :projects, column: :project_id, on_delete: :cascade
+    end
+  end
+end

ee/spec/factories/incident_management/project_incident_management_settings.rb

+# frozen_string_literal: true
+
+FactoryBot.define do
+  factory :project_incident_management_setting, class: IncidentManagement::ProjectIncidentManagementSetting do
+    project
+    create_issue false
+    issue_template_key nil
+    send_email false
+  end
+end

ee/spec/lib/gitlab/import_export/all_models.yml

@@ -79,6 +79,7 @@ project:
 - alerting_setting
 - webide_pipelines
 - reviews
+- incident_management_setting
 prometheus_metrics:
 - project
 - prometheus_alerts
@@ -99,3 +100,5 @@ reviews:
 - merge_request
 - author
 - notes
+incident_management_setting:
+- project

ee/spec/models/incident_management/project_incident_management_setting_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe IncidentManagement::ProjectIncidentManagementSetting do
+  set(:project) { create(:project, :repository, create_templates: :issue) }
+
+  describe 'Associations' do
+    it { is_expected.to belong_to(:project) }
+  end
+
+  describe 'Validations' do
+    describe 'validate issue_template_exists' do
+      subject { build(:project_incident_management_setting, project: project) }
+
+      context 'with create_issue enabled' do
+        before do
+          subject.create_issue = true
+        end
+
+        context 'with valid issue_template_key' do
+          before do
+            subject.issue_template_key = 'bug'
+          end
+
+          it { is_expected.to be_valid }
+        end
+
+        context 'with empty issue_template_key' do
+          before do
+            subject.issue_template_key = ''
+          end
+
+          it { is_expected.to be_valid }
+        end
+
+        context 'with nil issue_template_key' do
+          before do
+            subject.issue_template_key = nil
+          end
+
+          it { is_expected.to be_valid }
+        end
+
+        context 'with invalid issue_template_key' do
+          before do
+            subject.issue_template_key = 'unknown'
+          end
+
+          it { is_expected.to be_invalid }
+
+          it 'returns error' do
+            subject.valid?
+
+            expect(subject.errors[:issue_template_key]).to eq(['not found'])
+          end
+        end
+      end
+
+      context 'with create_issue disabled' do
+        before do
+          subject.create_issue = false
+        end
+
+        context 'with unknown issue_template_key' do
+          before do
+            subject.issue_template_key = 'unknown'
+          end
+
+          it { is_expected.to be_valid }
+        end
+      end
+    end
+  end
+end