Trigger webhook when feature flag is enabled or disabled

This commit implements a new feature to trigger webhook
when a feature flag is enabled or disabled.

app/models/concerns/triggerable_hooks.rb

@@ -13,7 +13,8 @@ module TriggerableHooks
     job_hooks:                :job_events,
     pipeline_hooks:           :pipeline_events,
     wiki_page_hooks:          :wiki_page_events,
-    deployment_hooks:         :deployment_events
+    deployment_hooks:         :deployment_events,
+    feature_flag_hooks:       :feature_flag_events
   }.freeze
 
   extend ActiveSupport::Concern

app/models/hooks/project_hook.rb

@@ -18,7 +18,8 @@ class ProjectHook < WebHook
     :job_hooks,
     :pipeline_hooks,
     :wiki_page_hooks,
-    :deployment_hooks
+    :deployment_hooks,
+    :feature_flag_hooks
   ]
 
   belongs_to :project

app/models/operations/feature_flag.rb

@@ -2,6 +2,7 @@
 
 module Operations
   class FeatureFlag < ApplicationRecord
+    include AfterCommitQueue
     include AtomicInternalId
     include IidRoutes
     include Limitable
@@ -77,6 +78,22 @@ module Operations
       Ability.issues_readable_by_user(issues, current_user)
     end
 
+    def execute_hooks(current_user)
+      run_after_commit do
+        feature_flag_data = Gitlab::DataBuilder::FeatureFlag.build(self, current_user)
+        project.execute_hooks(feature_flag_data, :feature_flag_hooks)
+      end
+    end
+
+    def hook_attrs
+      {
+        id: id,
+        name: name,
+        description: description,
+        active: active
+      }
+    end
+
     private
 
     def version_associations

app/services/feature_flags/update_service.rb

@@ -22,6 +22,10 @@ module FeatureFlags
 
         audit_event = audit_event(feature_flag)
 
+        if feature_flag.active_changed?
+          feature_flag.execute_hooks(current_user)
+        end
+
         if feature_flag.save
           save_audit_event(audit_event)
 

app/views/shared/web_hooks/_form.html.haml

@@ -78,6 +78,12 @@
         %strong= s_('Webhooks|Deployment events')
       %p.text-muted.ml-1
         = s_('Webhooks|This URL is triggered when a deployment starts, finishes, fails, or is canceled')
+    %li
+      = form.check_box :feature_flag_events, class: 'form-check-input'
+      = form.label :feature_flag_events, class: 'list-label form-check-label ml-1' do
+        %strong= s_('Webhooks|Feature Flag events')
+      %p.text-muted.ml-1
+        = s_('Webhooks|This URL is triggered when a feature flag is turned on or off')
 .form-group
   = form.label :enable_ssl_verification, s_('Webhooks|SSL verification'), class: 'label-bold checkbox'
   .form-check

changelogs/unreleased/sk-220898-feature-flag-webhook.yml

+---
+title: Add webhooks for feature flag
+merge_request: 41863
+author: Sashi
+type: added

db/migrate/20200908212414_add_feature_flag_events_to_web_hooks.rb

+# frozen_string_literal: true
+
+class AddFeatureFlagEventsToWebHooks < ActiveRecord::Migration[6.0]
+  DOWNTIME = false
+
+  def change
+    add_column :web_hooks, :feature_flag_events, :boolean, null: false, default: false
+  end
+end

db/schema_migrations/20200908212414

+a9605126178d887bbf526a4a33b7060b072eff7a8d6712e3552099f7e615f88b
\ No newline at end of file

db/structure.sql

@@ -17264,7 +17264,8 @@ CREATE TABLE web_hooks (
     encrypted_token_iv character varying,
     encrypted_url character varying,
     encrypted_url_iv character varying,
-    deployment_events boolean DEFAULT false NOT NULL
+    deployment_events boolean DEFAULT false NOT NULL,
+    feature_flag_events boolean DEFAULT false NOT NULL
 );
 
 CREATE SEQUENCE web_hooks_id_seq

doc/user/project/integrations/webhooks.md

@@ -1358,6 +1358,55 @@ X-Gitlab-Event: Deployment Hook
 
 Note that `deployable_id` is the ID of the CI job.
 
+### Feature Flag events
+
+Triggered when a feature flag is turned on or off.
+
+**Request Header**:
+
+```plaintext
+X-Gitlab-Event: Feature Flag Hook
+```
+
+**Request Body**:
+
+```json
+{
+  "object_kind": "feature_flag",
+  "project": {
+    "id": 1,
+    "name":"Gitlab Test",
+    "description":"Aut reprehenderit ut est.",
+    "web_url":"http://example.com/gitlabhq/gitlab-test",
+    "avatar_url":null,
+    "git_ssh_url":"git@example.com:gitlabhq/gitlab-test.git",
+    "git_http_url":"http://example.com/gitlabhq/gitlab-test.git",
+    "namespace":"GitlabHQ",
+    "visibility_level":20,
+    "path_with_namespace":"gitlabhq/gitlab-test",
+    "default_branch":"master",
+    "ci_config_path": null,
+    "homepage":"http://example.com/gitlabhq/gitlab-test",
+    "url":"http://example.com/gitlabhq/gitlab-test.git",
+    "ssh_url":"git@example.com:gitlabhq/gitlab-test.git",
+    "http_url":"http://example.com/gitlabhq/gitlab-test.git"
+  },
+  "user": {
+    "name": "Administrator",
+    "username": "root",
+    "avatar_url": "https://www.gravatar.com/avatar/e64c7d89f26bd1972efa854d13d7dd61?s=80&d=identicon",
+    "email": "admin@example.com"
+  },
+  "user_url": "http://example.com/root",
+  "object_attributes": {
+    "id": 6,
+    "name": "test-feature-flag",
+    "description": "test-feature-flag-description",
+    "active": true
+  }
+}
+```
+
 ## Image URL rewriting
 
 From GitLab 11.2, simple image references are rewritten to use an absolute URL

lib/gitlab/data_builder/feature_flag.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module DataBuilder
+    module FeatureFlag
+      extend self
+
+      def build(feature_flag, user)
+        {
+          object_kind: 'feature_flag',
+          project: feature_flag.project.hook_attrs,
+          user: user.hook_attrs,
+          user_url: Gitlab::UrlBuilder.build(user),
+          object_attributes: feature_flag.hook_attrs
+        }
+      end
+    end
+  end
+end

locale/gitlab.pot

@@ -29641,6 +29641,9 @@ msgstr ""
 msgid "Webhooks|Enable SSL verification"
 msgstr ""
 
+msgid "Webhooks|Feature Flag events"
+msgstr ""
+
 msgid "Webhooks|Issues events"
 msgstr ""
 
@@ -29668,6 +29671,9 @@ msgstr ""
 msgid "Webhooks|This URL is triggered when a deployment starts, finishes, fails, or is canceled"
 msgstr ""
 
+msgid "Webhooks|This URL is triggered when a feature flag is turned on or off"
+msgstr ""
+
 msgid "Webhooks|This URL will be triggered by a push to the repository"
 msgstr ""
 

spec/factories/project_hooks.rb

@@ -22,6 +22,7 @@ FactoryBot.define do
       pipeline_events { true }
       wiki_page_events { true }
       deployment_events { true }
+      feature_flag_events { true }
     end
   end
 end

spec/lib/gitlab/data_builder/feature_flag_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::DataBuilder::FeatureFlag do
+  let(:project) { create(:project) }
+  let(:user) { create(:user) }
+  let(:feature_flag) { create(:operations_feature_flag, project: project) }
+
+  describe '.build' do
+    let(:data) { described_class.build(feature_flag, user) }
+
+    it { expect(data).to be_a(Hash) }
+    it { expect(data[:object_kind]).to eq('feature_flag') }
+
+    it 'contains the correct object attributes' do
+      object_attributes = data[:object_attributes]
+
+      expect(object_attributes[:id]).to eq(feature_flag.id)
+      expect(object_attributes[:name]).to eq(feature_flag.name)
+      expect(object_attributes[:description]).to eq(feature_flag.description)
+      expect(object_attributes[:active]).to eq(feature_flag.active)
+    end
+  end
+end

spec/models/operations/feature_flag_spec.rb

@@ -261,4 +261,38 @@ RSpec.describe Operations::FeatureFlag do
       expect(flags.map(&:id)).to eq([feature_flag.id, feature_flag_b.id])
     end
   end
+
+  describe '#hook_attrs' do
+    it 'includes expected attributes' do
+      hook_attrs = {
+        id: subject.id,
+        name: subject.name,
+        description: subject.description,
+        active: subject.active
+      }
+      expect(subject.hook_attrs).to eq(hook_attrs)
+    end
+  end
+
+  describe "#execute_hooks" do
+    let_it_be(:user) { create(:user) }
+    let_it_be(:project) { create(:project) }
+    let_it_be(:feature_flag) { create(:operations_feature_flag, project: project) }
+
+    it 'does not execute the hook when feature_flag event is disabled' do
+      create(:project_hook, project: project, feature_flag_events: false)
+      expect(WebHookWorker).not_to receive(:perform_async)
+
+      feature_flag.execute_hooks(user)
+      feature_flag.touch
+    end
+
+    it 'executes hook when feature_flag event is enabled' do
+      hook = create(:project_hook, project: project, feature_flag_events: true)
+      expect(WebHookWorker).to receive(:perform_async).with(hook.id, an_instance_of(Hash), 'feature_flag_hooks')
+
+      feature_flag.execute_hooks(user)
+      feature_flag.touch
+    end
+  end
 end

spec/services/feature_flags/update_service_spec.rb

@@ -100,6 +100,13 @@ RSpec.describe FeatureFlags::UpdateService do
           include('Updated active from <strong>"true"</strong> to <strong>"false"</strong>.')
         )
       end
+
+      it 'executes hooks' do
+        hook = create(:project_hook, :all_events_enabled, project: project)
+        expect(WebHookWorker).to receive(:perform_async).with(hook.id, an_instance_of(Hash), 'feature_flag_hooks')
+
+        subject
+      end
     end
 
     context 'when scope active state is changed' do