Merge branch 'feature-flags-mvc-ee' into 'master'

Feature flags MVC

See merge request gitlab-org/gitlab-ee!7433

app/views/layouts/nav/sidebar/_project.html.haml

@@ -195,7 +195,7 @@
                     = _('Charts')
 
       - if project_nav_tab? :operations
-        = nav_link(controller: [:environments, :clusters, :user, :gcp]) do
+        = nav_link(controller: [:environments, :clusters, :user, :gcp, :feature_flags]) do
           = link_to metrics_project_environments_path(@project), class: 'shortcuts-operations' do
             .nav-icon-container
               = sprite_icon('cloud-gear')
@@ -203,7 +203,7 @@
               = _('Operations')
 
           %ul.sidebar-sub-level-items
-            = nav_link(controller: [:environments, :clusters, :user, :gcp], html_options: { class: "fly-out-top-item" } ) do
+            = nav_link(controller: [:environments, :clusters, :user, :gcp, :feature_flags], html_options: { class: "fly-out-top-item" } ) do
               = link_to metrics_project_environments_path(@project) do
                 %strong.fly-out-top-item-name
                   =  _('Operations')
@@ -249,6 +249,12 @@
                         %span= _("Got it!")
                         = sprite_icon('thumb-up')
 
+            - if project_nav_tab? :feature_flags
+              = nav_link(controller: :feature_flags) do
+                = link_to project_feature_flags_path(@project), title: _('Feature Flags'), class: 'shortcuts-feature-flags' do
+                  %span
+                    = _('Feature Flags')
+
       - if project_nav_tab? :container_registry
         = nav_link(controller: %w[projects/registry/repositories]) do
           = link_to project_container_registry_index_path(@project), class: 'shortcuts-container-registry' do

config/routes/project.rb

@@ -351,6 +351,10 @@ constraints(::Constraints::ProjectUrlConstrainer.new) do
         namespace :ci do
           resource :lint, only: [:show, :create]
         end
+
+        ## EE-specific
+        resources :feature_flags
+        ## EE-specific
       end
 
       draw :legacy_builds

db/schema.rb

@@ -1943,6 +1943,24 @@ ActiveRecord::Schema.define(version: 20180926140319) do
     t.string "nonce", null: false
   end
 
+  create_table "operations_feature_flags", id: :bigserial, force: :cascade do |t|
+    t.integer "project_id", null: false
+    t.boolean "active", null: false
+    t.datetime_with_timezone "created_at", null: false
+    t.datetime_with_timezone "updated_at", null: false
+    t.string "name", null: false
+    t.text "description"
+  end
+
+  add_index "operations_feature_flags", ["project_id", "name"], name: "index_operations_feature_flags_on_project_id_and_name", unique: true, using: :btree
+
+  create_table "operations_feature_flags_clients", id: :bigserial, force: :cascade do |t|
+    t.integer "project_id", null: false
+    t.string "token", null: false
+  end
+
+  add_index "operations_feature_flags_clients", ["project_id", "token"], name: "index_operations_feature_flags_clients_on_project_id_and_token", unique: true, using: :btree
+
   create_table "packages_maven_metadata", id: :bigserial, force: :cascade do |t|
     t.integer "package_id", limit: 8, null: false
     t.datetime_with_timezone "created_at", null: false
@@ -3233,6 +3251,8 @@ ActiveRecord::Schema.define(version: 20180926140319) do
   add_foreign_key "notes", "projects", name: "fk_99e097b079", on_delete: :cascade
   add_foreign_key "notification_settings", "users", name: "fk_0c95e91db7", on_delete: :cascade
   add_foreign_key "oauth_openid_requests", "oauth_access_grants", column: "access_grant_id", name: "fk_oauth_openid_requests_oauth_access_grants_access_grant_id"
+  add_foreign_key "operations_feature_flags", "projects", on_delete: :cascade
+  add_foreign_key "operations_feature_flags_clients", "projects", on_delete: :cascade
   add_foreign_key "packages_maven_metadata", "packages_packages", column: "package_id", name: "fk_be88aed360", on_delete: :cascade
   add_foreign_key "packages_package_files", "packages_packages", column: "package_id", name: "fk_86f0f182f8", on_delete: :cascade
   add_foreign_key "packages_packages", "projects", on_delete: :cascade

doc/user/project/operations/feature_flags.md

+# Feature Flags
+
+## Client libraries

ee/app/controllers/projects/feature_flags_controller.rb

+class Projects::FeatureFlagsController < Projects::ApplicationController
+  respond_to :html
+
+  before_action :authorize_read_feature_flag!
+  before_action :authorize_update_feature_flag!, only: [:edit, :update]
+  before_action :authorize_destroy_feature_flag!, only: [:destroy]
+
+  before_action :feature_flag, only: [:edit, :update, :destroy]
+
+  def index
+    @feature_flags = project.operations_feature_flags
+      .ordered
+      .page(params[:page]).per(30)
+  end
+
+  def new
+    @feature_flag = project.operations_feature_flags.new
+  end
+
+  def create
+    @feature_flag = project.operations_feature_flags.create(create_params)
+
+    if @feature_flag.persisted?
+      redirect_to project_feature_flags_path(@project), status: 302, notice: 'Feature flag was successfully created.'
+    else
+      render :new
+    end
+  end
+
+  def edit
+  end
+
+  def update
+    if feature_flag.update(update_params)
+      redirect_to project_feature_flags_path(@project), status: 302, notice: 'Feature flag was successfully updated.'
+    else
+      render :edit
+    end
+  end
+
+  def destroy
+    if feature_flag.destroy
+      redirect_to project_feature_flags_path(@project), status: 302, notice: 'Feature flag was successfully removed.'
+    else
+      redirect_to project_feature_flags_path(@project), status: 302, alert: 'Feature flag was not removed.'
+    end
+  end
+
+  protected
+
+  def feature_flag
+    @feature_flag ||= project.operations_feature_flags.find(params[:id])
+  end
+
+  def create_params
+    params.require(:operations_feature_flag)
+          .permit(:name, :description, :active)
+  end
+
+  def update_params
+    params.require(:operations_feature_flag)
+          .permit(:name, :description, :active)
+  end
+end

ee/app/helpers/ee/projects_helper.rb

@@ -25,9 +25,20 @@ module EE
         nav_tabs << :packages
       end
 
+      if can?(current_user, :read_feature_flag, project) && !nav_tabs.include?(:operations)
+        nav_tabs << :operations
+      end
+
       nav_tabs
     end
 
+    override :tab_ability_map
+    def tab_ability_map
+      tab_ability_map = super
+      tab_ability_map[:feature_flags] = :read_feature_flag
+      tab_ability_map
+    end
+
     override :project_permissions_settings
     def project_permissions_settings(project)
       super.merge(

ee/app/helpers/feature_flags_helper.rb

+# frozen_string_literal: true
+
+module FeatureFlagsHelper
+  include ::API::Helpers::RelatedResourcesHelpers
+
+  def unleash_api_url(project)
+    expose_url(api_v4_feature_flags_unleash_path(project_id: project.id))
+  end
+
+  def unleash_api_instance_id(project)
+    project.feature_flags_client_token
+  end
+end

ee/app/models/ee/project.rb

@@ -50,6 +50,9 @@ module EE
       has_many :prometheus_alerts, inverse_of: :project
       has_many :prometheus_alert_events, inverse_of: :project
 
+      has_many :operations_feature_flags, class_name: 'Operations::FeatureFlag'
+      has_one :operations_feature_flags_client, class_name: 'Operations::FeatureFlagsClient'
+
       scope :with_shared_runners_limit_enabled, -> { with_shared_runners.non_public_only }
 
       scope :mirror, -> { where(mirror: true) }
@@ -559,6 +562,11 @@ module EE
       change_head(root_ref) if root_ref.present? && root_ref != default_branch
     end
 
+    def feature_flags_client_token
+      instance = operations_feature_flags_client || create_operations_feature_flags_client!
+      instance.token
+    end
+
     private
 
     def set_override_pull_mirror_available

ee/app/models/license.rb

@@ -67,6 +67,7 @@ class License < ActiveRecord::Base
     custom_project_templates
     packages
     code_owner_as_approver_suggestion
+    feature_flags
   ].freeze
 
   EEU_FEATURES = EEP_FEATURES + %i[

ee/app/models/operations/feature_flag.rb

+module Operations
+  class FeatureFlag < ActiveRecord::Base
+    self.table_name = 'operations_feature_flags'
+
+    belongs_to :project
+
+    validates :project, presence: true
+    validates :name,
+      presence: true,
+      length: 2..63,
+      format: {
+        with: Gitlab::Regex.feature_flag_regex,
+        message: Gitlab::Regex.feature_flag_regex_message
+      }
+    validates :name, uniqueness: { scope: :project_id }
+    validates :description, allow_blank: true, length: 0..255
+
+    scope :ordered, -> { order(:name) }
+  end
+end

ee/app/models/operations/feature_flags_client.rb

+module Operations
+  class FeatureFlagsClient < ActiveRecord::Base
+    include TokenAuthenticatable
+
+    self.table_name = 'operations_feature_flags_clients'
+
+    belongs_to :project
+
+    validates :project, presence: true
+    validates :token, presence: true
+
+    add_authentication_token_field :token
+
+    before_validation :ensure_token!
+
+    def self.find_for_project_and_token(project, token)
+      return unless project
+      return unless token
+
+      find_by(token: token, project: project)
+    end
+  end
+end

ee/app/policies/ee/project_policy.rb

@@ -8,6 +8,7 @@ module EE
       approvers
       vulnerability_feedback
       license_management
+      feature_flag
     ].freeze
 
     prepended do
@@ -65,6 +66,11 @@ module EE
         @subject.feature_available?(:license_management)
       end
 
+      with_scope :subject
+      condition(:feature_flags_disabled) do
+        !@subject.feature_available?(:feature_flags)
+      end
+
       rule { admin }.enable :change_repository_storage
 
       rule { support_bot }.enable :guest_access
@@ -99,6 +105,11 @@ module EE
         enable :admin_board
         enable :admin_vulnerability_feedback
         enable :create_package
+        enable :read_feature_flag
+        enable :create_feature_flag
+        enable :update_feature_flag
+        enable :destroy_feature_flag
+        enable :admin_feature_flag
       end
 
       rule { can?(:public_access) }.enable :read_package
@@ -117,6 +128,10 @@ module EE
         prevent(*create_read_update_admin_destroy(:package))
       end
 
+      rule { feature_flags_disabled }.policy do
+        prevent(*create_read_update_admin_destroy(:feature_flag))
+      end
+
       rule { can?(:maintainer_access) }.policy do
         enable :push_code_to_protected_branches
         enable :admin_path_locks

ee/app/views/projects/feature_flags/_configure_feature_flags_button.html.haml

+- if can?(current_user, :admin_feature_flag, @project)
+  %button.btn.btn-primary.btn-inverted.append-right-8{ type: 'button', data: { toggle: 'modal', target: '#configure-feature-flags-modal' } }>
+    = s_('FeatureFlags|Configure')

ee/app/views/projects/feature_flags/_configure_feature_flags_modal.html.haml

+- if can?(current_user, :admin_feature_flag, @project)
+  #configure-feature-flags-modal.modal{ tabindex: -1,
+    role: 'dialog' }
+    .modal-dialog{ role: 'document' }
+      .modal-content
+        .modal-header
+          %h4.modal-title
+            = s_('FeatureFlags|Configure feature flags')
+          %button.close{ type: 'button', data: { dismiss: 'modal' }, aria: { label: _('Close') } }
+            %span{ "aria-hidden": true } ×
+        .modal-body
+          %p
+            - client_libraries_url = help_page_path("user/project/operations/feature_flags", anchor: "client-libraries")
+            = s_('FeatureFlags|Install a %{docs_link_start}compatible client library%{docs_link_end} and specify the API URL, application name, and instance ID during the configuration setup.').html_safe % { docs_link_start: %Q{<a href="#{client_libraries_url}">}.html_safe,
+              docs_link_end: '</a>'.html_safe }
+            = link_to s_('FeatureFlags|More information'), help_page_path("user/project/operations/feature_flags")
+
+          .form-group
+            = label_tag :api_url, s_('FeatureFlags|API URL'), class: 'label-bold'
+            .input-group
+              = text_field_tag :api_url,
+                unleash_api_url(@project),
+                readonly: true,
+                class: "form-control js-select-on-focus"
+              %span.input-group-append
+                = clipboard_button(target: '#api_url',
+                  title: _("Copy URL to clipboard"),
+                  placement: "left",
+                  container: '#configure-feature-flags-modal',
+                  class: "input-group-text btn btn-default")
+
+          .form-group
+            = label_tag :instance_id, s_('FeatureFlags|Instance ID'), class: 'label-bold'
+            .input-group
+              = text_field_tag :instance_id,
+                unleash_api_instance_id(@project),
+                readonly: true,
+                class: "form-control js-select-on-focus"
+              %span.input-group-append
+                = clipboard_button(target: '#instance_id',
+                  title: _("Copy ID to clipboard"),
+                  placement: "left",
+                  container: '#configure-feature-flags-modal',
+                  class: "input-group-text btn btn-default")
+
+          .form-group
+            = label_tag :application_name, s_('FeatureFlags|Application name'), class: 'label-bold'
+            .input-group
+              = text_field_tag :application_name,
+                "production",
+                readonly: true,
+                class: "form-control js-select-on-focus"
+              %span.input-group-append
+                = clipboard_button(target: '#application_name',
+                  title: _("Copy name to clipboard"),
+                  placement: "left",
+                  container: '#configure-feature-flags-modal',
+                  class: "input-group-text btn btn-default")

ee/app/views/projects/feature_flags/_delete_feature_flag_modal.html.haml

+- if can?(current_user, :destroy_feature_flag, @project)
+  .modal{ id: "delete-feature-flag-modal-#{feature_flag.id}",
+    tabindex: -1,
+    role: 'dialog' }
+    .modal-dialog{ role: 'document' }
+      .modal-content
+        .modal-header
+          %h4.modal-title.d-flex.mw-100
+            - truncated_feature_flag_name = capture do
+              %span.text-truncate.prepend-left-4.append-right-4= feature_flag.name
+            = s_('FeatureFlags|Delete %{feature_flag_name}?').html_safe % { feature_flag_name: truncated_feature_flag_name }
+          %button.close{ type: 'button', data: { dismiss: 'modal' }, aria: { label: _('Close') } }
+            %span{ "aria-hidden": true } ×
+        .modal-body
+          %p
+            - monospace_feature_flag_name = capture do
+              %span.text-monospace= feature_flag.name
+            = s_('FeatureFlags|Feature flag %{feature_flag_name} will be removed. Are you sure?').html_safe % { feature_flag_name: monospace_feature_flag_name }
+        .modal-footer
+          %button{ type: 'button', data: { dismiss: 'modal' }, class: 'btn btn-default' } Cancel
+
+          = button_to 'Delete',
+            project_feature_flag_path(@project, feature_flag),
+            title: 'Delete',
+            method: :delete,
+            class: 'btn btn-remove'

ee/app/views/projects/feature_flags/_empty_state.html.haml

+.border-top
+  .row.empty-state
+    .col-12
+      .svg-content
+        = image_tag 'illustrations/feature_flag.svg'
+
+    .col-12
+      .text-content
+        %h4.text-center= s_('FeatureFlags|Get started with feature flags')
+        %p
+          = s_('FeatureFlags|Feature flags allow you to configure your code into different flavors by dynamically toggling certain functionality.')
+          = link_to 'More information', help_page_path("user/project/operations/feature_flags")
+
+        = render 'new_feature_flag_button'
+        = render 'configure_feature_flags_button'

ee/app/views/projects/feature_flags/_errors.html.haml

+#error_explanation
+  .alert.alert-danger
+    - @feature_flag.errors.full_messages.each do |message|
+      %p= message

ee/app/views/projects/feature_flags/_form.html.haml

+- if @feature_flag.errors.any?
+  = render 'errors'
+
+%fieldset
+  .row
+    .form-group.col-md-4
+      = f.label :name, class: 'label-bold', for: 'feature_flag_name' do
+        = s_('FeatureFlags|Name')
+      = f.text_field :name, class: "form-control", id: "feature_flag_name"
+  .row
+    .form-group.col-md-4
+      = f.label :description, class: 'label-bold', for: 'feature_flag_description' do
+        = s_('FeatureFlags|Description')
+      = f.text_area :description, class: "form-control", id: "feature_flag_description", rows: 4
+  .row
+    .form-group.col-md-1
+      = f.label :active, class: 'label-bold' do
+        = s_('FeatureFlags|Status')
+      .form-check
+        = f.check_box :active, id: 'feature_flag_status', class: 'form-check-input'
+        = f.label :active, for: 'feature_flag_status', class: 'form-check-label' do
+          = s_('FeatureFlags|Active')
+.form-actions
+  - if @feature_flag.persisted?
+    = f.submit s_('FeatureFlags|Save changes'), class: "btn btn-success"
+  - else
+    = f.submit s_('FeatureFlags|Create feature flag'), class: "btn btn-success"
+  .float-right
+    = link_to _('Cancel'), project_feature_flags_path(@project), class: 'btn btn-cancel'

ee/app/views/projects/feature_flags/_new_feature_flag_button.html.haml

+- if can?(current_user, :create_feature_flag, @project)
+  = link_to new_project_feature_flag_path(@project), class: 'btn btn-success' do
+    = s_('FeatureFlags|New Feature Flag')

ee/app/views/projects/feature_flags/_table.html.haml

+.table-holder.border-top
+  .gl-responsive-table-row.table-row-header{ role: 'row' }
+    .table-section.section-10{ role: 'columnheader' }= s_('FeatureFlags|Status')
+    .table-section.section-50{ role: 'columnheader' }= s_('FeatureFlags|Feature flag')
+  - @feature_flags.each do |feature_flag|
+    = render 'delete_feature_flag_modal', { feature_flag: feature_flag }
+
+    .gl-responsive-table-row{ role: 'row' }
+      .table-section.section-10{ role: 'gridcell' }
+        .table-mobile-header{ role: "rowheader" }= s_('FeatureFlags|Status')
+        .table-mobile-content
+          - if feature_flag.active?
+            %span.badge.badge-success
+              = s_('FeatureFlags|Active')
+          - else
+            %span.badge.badge-danger
+              = s_('FeatureFlags|Inactive')
+
+      .table-section.section-50{ role: 'gridcell' }
+        .table-mobile-header{ role: "rowheader" }= s_('FeatureFlags|Feature Flag')
+        .table-mobile-content.d-flex.flex-column
+          .text-monospace.text-truncate= feature_flag.name
+          .text-secondary.text-truncate= feature_flag.description
+
+      .table-section.section-40.table-button-footer{ role: 'gridcell' }
+        .table-action-buttons.btn-group
+          - if can?(current_user, :update_feature_flag, @project)
+            = link_to edit_project_feature_flag_path(@project, feature_flag),
+                class: 'btn btn-default has-tooltip',
+                type: 'button',
+                title: _('Edit') do
+              = sprite_icon('pencil', size: 16)
+
+          - if can?(current_user, :destroy_feature_flag, @project)
+            %button.btn.btn-danger.has-tooltip{ type: 'button',
+                data: { toggle: 'modal',
+                  target: "#delete-feature-flag-modal-#{feature_flag.id}" },
+                title: _('Delete') }
+              = sprite_icon('remove', size: 16)
+
+= paginate @feature_flags, theme: "gitlab"

ee/app/views/projects/feature_flags/edit.html.haml

+- add_to_breadcrumbs "Feature Flags", project_feature_flags_path(@project)
+- breadcrumb_title @feature_flag.name
+- page_title s_('FeatureFlags|Edit Feature Flag')
+%h3.page-title
+  = s_('FeatureFlags|Edit %{feature_flag_name}') % { feature_flag_name: @feature_flag.name }
+%hr.clearfix
+%div
+  = form_for [@project, @feature_flag], url: project_feature_flag_path(@project, @feature_flag), html: { class: 'fieldset-form' } do |f|
+    = render 'form', { f: f }

ee/app/views/projects/feature_flags/index.html.haml

+- page_title _('Feature Flags')
+
+= render 'configure_feature_flags_modal'
+
+- if @feature_flags.empty?
+  = render 'empty_state'
+- else
+  %h3.page-title.with-button
+    = _('Feature Flags')
+
+    .pull-right
+      = render 'configure_feature_flags_button'
+      = render 'new_feature_flag_button'
+
+  = render 'table'

ee/app/views/projects/feature_flags/new.html.haml

+- @breadcrumb_link = new_project_feature_flag_path(@project)
+- add_to_breadcrumbs "Feature Flags", project_feature_flags_path(@project)
+- breadcrumb_title s_('FeatureFlags|New')
+- page_title s_('FeatureFlags|New Feature Flag')
+%h3.page-title
+  = s_('FeatureFlags|New Feature Flag')
+%hr.clearfix
+%div
+  = form_for [@project, @feature_flag], url: project_feature_flags_path(@project), html: { class: 'fieldset-form' } do |f|
+    = render 'form', { f: f }

ee/changelogs/unreleased/feature-flags-mvc-ee.yml

+---
+title: Add Feature Flags MVC
+merge_request: 7433
+author:
+type: added

ee/db/migrate/20180626171125_add_feature_flags_to_projects.rb

+class AddFeatureFlagsToProjects < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  # Set this constant to true if this migration requires downtime.
+  DOWNTIME = false
+
+  def change
+    create_table :operations_feature_flags, id: :bigserial do |t|
+      t.integer :project_id, null: false
+      t.boolean :active, null: false
+
+      t.datetime_with_timezone :created_at, null: false
+      t.datetime_with_timezone :updated_at, null: false
+
+      t.string :name, null: false
+      t.text :description
+
+      t.foreign_key :projects, column: :project_id, on_delete: :cascade
+
+      t.index [:project_id, :name], unique: true
+    end
+
+    create_table :operations_feature_flags_clients, id: :bigserial  do |t|
+      t.integer :project_id, null: false
+      t.string :token, null: false
+
+      t.index [:project_id, :token], unique: true
+
+      t.foreign_key :projects, column: :project_id, on_delete: :cascade
+    end
+  end
+end

ee/lib/api/unleash.rb

+module API
+  class Unleash < Grape::API
+    include PaginationParams
+
+    namespace :feature_flags do
+      resource :unleash, requirements: API::PROJECT_ENDPOINT_REQUIREMENTS do
+        params do
+          requires :project_id, type: String, desc: 'The ID of a project'
+          optional :instance_id, type: String, desc: 'The Instance ID of Unleash Client'
+        end
+        route_param :project_id do
+          before do
+            authorize_by_unleash_instance_id!
+            authorize_feature_flags_feature!
+          end
+
+          get do
+            # not supported yet
+            status :ok
+          end
+
+          get 'features' do
+            present project, with: ::EE::API::Entities::UnleashFeatures
+          end
+
+          post 'client/register' do
+            # not supported yet
+            status :ok
+          end
+
+          post 'client/metrics' do
+            # not supported yet
+            status :ok
+          end
+        end
+      end
+    end
+
+    helpers do
+      def project
+        @project ||= find_project(params[:project_id])
+      end
+
+      def unleash_instance_id
+        params[:instance_id] || env['HTTP_UNLEASH_INSTANCEID']
+      end
+
+      def authorize_by_unleash_instance_id!
+        unauthorized! unless Operations::FeatureFlagsClient
+          .find_for_project_and_token(project, unleash_instance_id)
+      end
+
+      def authorize_feature_flags_feature!
+        forbidden! unless project.feature_available?(:feature_flags)
+      end
+    end
+  end
+end

ee/lib/ee/api/entities.rb

@@ -427,6 +427,27 @@ module EE
           object.geo_node.missing_oauth_application?
         end
       end
+
+      class UnleashFeature < Grape::Entity
+        expose :name
+        expose :description, unless: ->(feature) { feature.description.nil? }
+        expose :active, as: :enabled
+      end
+
+      class UnleashFeatures < Grape::Entity
+        expose :version
+        expose :features, with: UnleashFeature
+
+        private
+
+        def version
+          1
+        end
+
+        def features
+          object.operations_feature_flags.ordered
+        end
+      end
     end
   end
 end

ee/lib/ee/gitlab/regex.rb

@@ -28,6 +28,15 @@ module EE
       def maven_app_group_regex
         maven_app_name_regex
       end
+
+      def feature_flag_regex
+        /\A[a-z]([-_a-z0-9]*[a-z0-9])?\z/
+      end
+
+      def feature_flag_regex_message
+        "can contain only lowercase letters, digits, '_' and '-'. " \
+        "Must start with a letter, and cannot end with '-' or '_'"
+      end
     end
   end
 end

ee/spec/controllers/projects/feature_flags_controller_spec.rb

+require 'spec_helper'
+
+describe Projects::FeatureFlagsController do
+  include Gitlab::Routing
+
+  set(:user) { create(:user) }
+  set(:project) { create(:project) }
+  let(:feature_enabled) { true }
+
+  before do
+    project.add_developer(user)
+
+    sign_in(user)
+    stub_licensed_features(feature_flags: feature_enabled)
+  end
+
+  describe 'GET index' do
+    render_views
+
+    subject { get(:index, view_params) }
+
+    context 'when there is no feature flags' do
+      before do
+        subject
+      end
+
+      it 'shows an empty state with buttons' do
+        expect(response).to be_ok
+        expect(response).to render_template('_empty_state')
+        expect(response).to render_template('_configure_feature_flags_button')
+        expect(response).to render_template('_new_feature_flag_button')
+      end
+    end
+
+    context 'for a list of feature flags' do
+      let!(:feature_flags) { create_list(:operations_feature_flag, 50, project: project) }
+
+      before do
+        subject
+      end
+
+      it 'shows an list of feature flags with buttons' do
+        expect(response).to be_ok
+        expect(response).to render_template('_table')
+        expect(response).to render_template('_configure_feature_flags_button')
+        expect(response).to render_template('_new_feature_flag_button')
+      end
+    end
+
+    context 'when feature is not available' do
+      let(:feature_enabled) { false }
+
+      before do
+        subject
+      end
+
+      it 'shows not found' do
+        expect(subject).to have_gitlab_http_status(404)
+      end
+    end
+  end
+
+  describe 'GET new' do
+    render_views
+
+    subject { get(:new, view_params) }
+
+    it 'renders the form' do
+      subject
+
+      expect(response).to be_ok
+      expect(response).to render_template('new')
+      expect(response).to render_template('_form')
+    end
+  end
+
+  describe 'POST create' do
+    render_views
+
+    subject { post(:create, params) }
+
+    context 'when creating a new feature flag' do
+      let(:params) do
+        view_params.merge(operations_feature_flag: { name: 'my_feature_flag', active: true })
+      end
+
+      it 'creates and redirects to list' do
+        subject
+
+        expect(response).to redirect_to(project_feature_flags_path(project))
+      end
+    end
+
+    context 'when a feature flag already exists' do
+      let!(:feature_flag) { create(:operations_feature_flag, project: project, name: 'my_feature_flag') }
+
+      let(:params) do
+        view_params.merge(operations_feature_flag: { name: 'my_feature_flag', active: true })
+      end
+
+      it 'shows an error' do
+        subject
+
+        expect(response).to render_template('new')
+        expect(response).to render_template('_errors')
+      end
+    end
+  end
+
+  describe 'PUT update' do
+    let!(:feature_flag) { create(:operations_feature_flag, project: project, name: 'my_feature_flag') }
+
+    render_views
+
+    subject { post(:create, params) }
+
+    context 'when updating an existing feature flag' do
+      let(:params) do
+        view_params.merge(
+          id: feature_flag.id,
+          operations_feature_flag: { name: 'my_feature_flag_v2', active: true }
+        )
+      end
+
+      it 'updates and redirects to list' do
+        subject
+
+        expect(response).to redirect_to(project_feature_flags_path(project))
+      end
+    end
+
+    context 'when using existing name of the feature flag' do
+      let!(:other_feature_flag) { create(:operations_feature_flag, project: project, name: 'other_feature_flag') }
+
+      let(:params) do
+        view_params.merge(operations_feature_flag: { name: 'other_feature_flag', active: true })
+      end
+
+      it 'shows an error' do
+        subject
+
+        expect(response).to render_template('new')
+        expect(response).to render_template('_errors')
+      end
+    end
+  end
+
+  private
+
+  def view_params
+    { namespace_id: project.namespace, project_id: project }
+  end
+end

ee/spec/factories/operations/feature_flags.rb

+FactoryBot.define do
+  factory :operations_feature_flag, class: Operations::FeatureFlag do
+    sequence(:name) { |n| "feature_flag_#{n}" }
+    project
+    active true
+  end
+end

ee/spec/factories/operations/feature_flags_clients.rb

+FactoryBot.define do
+  factory :operations_feature_flags_client, class: Operations::FeatureFlagsClient do
+    project
+  end
+end

ee/spec/features/projects/feature_flags_spec.rb

+require 'spec_helper'
+
+describe 'Feature Flags', :js do
+  using RSpec::Parameterized::TableSyntax
+
+  invalid_input_table = proc do
+    'with space' | '' | 'Name can contain only'
+    '<script>' | '' | 'Name can contain only'
+    'x' * 100 | '' | 'Name is too long'
+    'some-name' | 'y' * 1001 | 'Description is too long'
+  end
+
+  let(:user) {create(:user)}
+  let(:project) {create(:project, namespace: user.namespace)}
+
+  before do
+    stub_licensed_features(feature_flags: true)
+    sign_in(user)
+  end
+
+  it 'shows empty state' do
+    visit(project_feature_flags_path(project))
+
+    expect_empty_state
+  end
+
+  context 'when creating a new feature flag' do
+    context 'and input is valid' do
+      where(:name, :description, :status) do
+        'my-active-flag' | 'a new flag' | true
+        'my-inactive-flag' | '' | false
+      end
+
+      with_them do
+        it 'adds the feature flag to the table' do
+          add_feature_flag(name, description, status)
+
+          expect_feature_flag(name, description, status)
+          expect(page).to have_selector '.flash-container', text: 'successfully created'
+        end
+      end
+    end
+
+    context 'and input is invalid' do
+      where(:name, :description, :error_message, &invalid_input_table)
+
+      with_them do
+        it 'displays an error message' do
+          add_feature_flag(name, description, false)
+
+          expect(page).to have_selector '.alert-danger', text: error_message
+        end
+      end
+    end
+  end
+
+  context 'when editing a feature flag' do
+    before do
+      add_feature_flag('feature-flag-to-edit', 'with some description', false)
+    end
+
+    context 'and input is valid' do
+      it 'updates the feature flag' do
+        name = 'new-name'
+        description = 'new description'
+
+        edit_feature_flag('feature-flag-to-edit', name, description, true)
+
+        expect_feature_flag(name, description, true)
+        expect(page).to have_selector '.flash-container', text: 'successfully updated'
+      end
+    end
+
+    context 'and input is invalid' do
+      where(:name, :description, :error_message, &invalid_input_table)
+
+      with_them do
+        it 'displays an error message' do
+          edit_feature_flag('feature-flag-to-edit', name, description, false)
+
+          expect(page).to have_selector '.alert-danger', text: error_message
+        end
+      end
+    end
+  end
+
+  context 'when deleting a feature flag' do
+    before do
+      add_feature_flag('feature-flag-to-delete', 'with some description', false)
+    end
+
+    context 'and no feature flags are left' do
+      it 'shows empty state' do
+        visit(project_feature_flags_path(project))
+
+        delete_feature_flag('feature-flag-to-delete')
+
+        expect_empty_state
+      end
+    end
+
+    context 'and there is a feature flag left' do
+      before do
+        add_feature_flag('another-feature-flag', '', true)
+      end
+
+      it 'shows feature flag table without deleted feature flag' do
+        visit(project_feature_flags_path(project))
+
+        delete_feature_flag('feature-flag-to-delete')
+
+        expect_feature_flag('another-feature-flag', '', true)
+      end
+    end
+
+    it 'does not delete if modal is cancelled' do
+      visit(project_feature_flags_path(project))
+
+      delete_feature_flag('feature-flag-to-delete', false)
+
+      expect_feature_flag('feature-flag-to-delete', 'with some description', false)
+    end
+  end
+
+  private
+
+  def add_feature_flag(name, description, status)
+    visit(new_project_feature_flag_path(project))
+
+    fill_in 'Name', with: name
+    fill_in 'Description', with: description
+
+    if status
+      check('Active')
+    else
+      uncheck('Active')
+    end
+
+    click_button 'Create feature flag'
+  end
+
+  def delete_feature_flag(name, confirm = true)
+    delete_button = find('.gl-responsive-table-row', text: name).find('.btn-danger[title="Delete"]')
+    delete_button.click
+
+    within '.modal' do
+      if confirm
+        click_button 'Delete'
+      else
+        click_button 'Cancel'
+      end
+    end
+  end
+
+  def edit_feature_flag(old_name, new_name, new_description, new_status)
+    visit(project_feature_flags_path(project))
+    edit_button = find('.gl-responsive-table-row', text: old_name).find('.btn-default[title="Edit"]')
+    edit_button.click
+
+    fill_in 'Name', with: new_name
+    fill_in 'Description', with: new_description
+
+    if new_status
+      check('Active')
+    else
+      uncheck('Active')
+    end
+
+    click_button 'Save changes'
+  end
+
+  def expect_empty_state
+    expect(page).to have_text 'Get started with feature flags'
+    expect(page).to have_selector('.btn-success', text: 'New Feature Flag')
+    expect(page).to have_selector('.btn-primary.btn-inverted', text: 'Configure')
+  end
+
+  def expect_feature_flag(name, description, status)
+    expect(current_path).to eq project_feature_flags_path(project)
+    expect(page).to have_selector '.table-section .badge', text: status ? 'Active' : 'Inactive'
+    expect(page).to have_selector '.table-section', text: name
+    expect(page).to have_selector '.table-section', text: description
+  end
+end

ee/spec/fixtures/api/schemas/unleash/unleash.json

+{
+  "additionalProperties": false,
+  "properties": {
+    "features": {
+      "items": {
+        "$ref": "unleash_feature.json"
+      },
+      "minItems": 0,
+      "type": "array"
+    },
+    "version": {
+      "type": "integer"
+    }
+  },
+  "required": [
+    "version",
+    "features"
+  ],
+  "type": "object"
+}

ee/spec/fixtures/api/schemas/unleash/unleash_feature.json

+{
+  "type": "object",
+  "additionalProperties": false,
+  "required": [
+    "name",
+    "enabled"
+  ],
+  "properties": {
+    "name": {
+      "type": "string"
+    },
+    "enabled": {
+      "type": "boolean"
+    },
+    "description": {
+      "type": "string"
+    }
+  }
+}

ee/spec/helpers/feature_flags_helper_spec.rb

+require 'spec_helper'
+
+describe FeatureFlagsHelper do
+  set(:project) { create(:project) }
+
+  context '#unleash_api_url' do
+    subject { helper.unleash_api_url(project) }
+
+    it { is_expected.to end_with("/api/v4/feature_flags/unleash/#{project.id}") }
+  end
+
+  context '#unleash_api_instance_id' do
+    subject { helper.unleash_api_instance_id(project) }
+
+    it { is_expected.not_to be_empty }
+  end
+end

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

@@ -56,6 +56,8 @@ project:
 - vulnerability_feedback
 - vulnerability_identifiers
 - vulnerability_scanners
+- operations_feature_flags
+- operations_feature_flags_client
 - prometheus_alerts
 - prometheus_alert_events
 - software_license_policies

ee/spec/lib/gitlab/regex_spec.rb

@@ -9,4 +9,14 @@ describe Gitlab::Regex do
     it { is_expected.to match('foo*Z') }
     it { is_expected.not_to match('!!()()') }
   end
+
+  describe '.feature_flag_regex' do
+    subject { described_class.feature_flag_regex }
+
+    it { is_expected.to match('foo') }
+    it { is_expected.to match('f_feature_flag') }
+    it { is_expected.not_to match('MY_FEATURE_FLAG') }
+    it { is_expected.not_to match('my feature flag') }
+    it { is_expected.not_to match('!!()()') }
+  end
 end

ee/spec/models/operations/feature_flag_spec.rb

+require 'spec_helper'
+
+describe Operations::FeatureFlag do
+  subject { create(:operations_feature_flag) }
+
+  describe 'associations' do
+    it { is_expected.to belong_to(:project) }
+  end
+
+  describe 'validations' do
+    it { is_expected.to validate_presence_of(:project) }
+    it { is_expected.to validate_presence_of(:name) }
+    it { is_expected.to validate_uniqueness_of(:name).scoped_to(:project_id) }
+  end
+end

ee/spec/models/operations/feature_flags_client_spec.rb

+require 'spec_helper'
+
+describe Operations::FeatureFlagsClient do
+  subject { create(:operations_feature_flags_client) }
+
+  describe 'associations' do
+    it { is_expected.to belong_to(:project) }
+  end
+
+  describe 'validations' do
+    it { is_expected.to validate_presence_of(:project) }
+  end
+
+  describe '#token' do
+    it "ensures that token is always set" do
+      expect(subject.token).not_to be_empty
+    end
+  end
+end

ee/spec/models/project_spec.rb

@@ -1767,4 +1767,24 @@ describe Project do
         .and_return(ref)
     end
   end
+
+  describe '#feature_flags_client_token' do
+    let(:project) { create(:project) }
+
+    subject { project.feature_flags_client_token }
+
+    context 'when there is no access token' do
+      it "creates a new one" do
+        is_expected.not_to be_empty
+      end
+    end
+
+    context 'when there is access token' do
+      let!(:instance) { create(:operations_feature_flags_client, project: project, token: 'token') }
+
+      it "provides an existing one" do
+        is_expected.to eq('token')
+      end
+    end
+  end
 end

ee/spec/requests/api/unleash_spec.rb

+require 'spec_helper'
+
+describe API::Unleash do
+  set(:project) { create(:project) }
+  let(:project_id) { project.id }
+  let(:feature_enabled) { true }
+  let(:params) { }
+  let(:headers) { }
+
+  before do
+    stub_licensed_features(feature_flags: feature_enabled)
+  end
+
+  shared_examples 'authenticated request' do
+    context 'when using instance id' do
+      let(:client) { create(:operations_feature_flags_client, project: project) }
+      let(:params) { { instance_id: client.token } }
+
+      it 'responds with OK' do
+        subject
+
+        expect(response).to have_gitlab_http_status(200)
+      end
+
+      context 'when feature is not available' do
+        let(:feature_enabled) { false }
+
+        it 'responds with forbidden' do
+          subject
+
+          expect(response).to have_gitlab_http_status(403)
+        end
+      end
+    end
+
+    context 'when using header' do
+      let(:client) { create(:operations_feature_flags_client, project: project) }
+      let(:headers) { { "UNLEASH-INSTANCEID" => client.token }}
+
+      it 'responds with OK' do
+        subject
+
+        expect(response).to have_gitlab_http_status(200)
+      end
+    end
+
+    context 'when using bogus instance id' do
+      let(:params) { { instance_id: 'token' } }
+
+      it 'responds with unauthorized' do
+        subject
+
+        expect(response).to have_gitlab_http_status(401)
+      end
+    end
+
+    context 'when using not existing project' do
+      let(:project_id) { -5000 }
+      let(:params) { { instance_id: 'token' } }
+
+      it 'responds with unauthorized' do
+        subject
+
+        expect(response).to have_gitlab_http_status(401)
+      end
+    end
+  end
+
+  describe 'GET /feature_flags/unleash/:project_id/features' do
+    subject { get api("/feature_flags/unleash/#{project_id}/features"), params, headers }
+
+    it_behaves_like 'authenticated request'
+
+    context 'with a list of feature flag' do
+      let(:client) { create(:operations_feature_flags_client, project: project) }
+      let(:headers) { { "UNLEASH-INSTANCEID" => client.token }}
+      let!(:enable_feature_flag) { create(:operations_feature_flag, project: project, name: 'feature1', active: true) }
+      let!(:disabled_feature_flag) { create(:operations_feature_flag, project: project, name: 'feature2', active: false) }
+
+      it 'responds with a list' do
+        subject
+
+        expect(response).to have_gitlab_http_status(200)
+        expect(json_response['version']).to eq(1)
+        expect(json_response['features']).not_to be_empty
+        expect(json_response['features'].first['name']).to eq('feature1')
+      end
+
+      it 'matches json schema' do
+        subject
+
+        expect(response).to have_gitlab_http_status(:ok)
+        expect(response).to match_response_schema('unleash/unleash', dir: 'ee')
+      end
+    end
+  end
+
+  describe 'POST /feature_flags/unleash/:project_id/client/register' do
+    subject { post api("/feature_flags/unleash/#{project_id}/client/register"), params, headers }
+
+    it_behaves_like 'authenticated request'
+  end
+
+  describe 'POST /feature_flags/unleash/:project_id/client/metrics' do
+    subject { post api("/feature_flags/unleash/#{project_id}/client/metrics"), params, headers }
+
+    it_behaves_like 'authenticated request'
+  end
+end

lib/api/api.rb

@@ -167,6 +167,7 @@ module API
     mount ::EE::API::Boards
     mount ::EE::API::GroupBoards
 
+    mount ::API::Unleash
     mount ::API::EpicIssues
     mount ::API::Epics
     mount ::API::Geo

locale/gitlab.pot

@@ -2254,6 +2254,9 @@ msgstr ""
 msgid "Copy incoming email address to clipboard"
 msgstr ""
 
+msgid "Copy name to clipboard"
+msgstr ""
+
 msgid "Copy reference to clipboard"
 msgstr ""
 
@@ -3177,6 +3180,81 @@ msgstr ""
 msgid "Faster as it re-uses the project workspace (falling back to clone if it doesn't exist)"
 msgstr ""
 
+msgid "Feature Flags"
+msgstr ""
+
+msgid "FeatureFlags|API URL"
+msgstr ""
+
+msgid "FeatureFlags|Active"
+msgstr ""
+
+msgid "FeatureFlags|Application name"
+msgstr ""
+
+msgid "FeatureFlags|Configure"
+msgstr ""
+
+msgid "FeatureFlags|Configure feature flags"
+msgstr ""
+
+msgid "FeatureFlags|Create feature flag"
+msgstr ""
+
+msgid "FeatureFlags|Delete %{feature_flag_name}?"
+msgstr ""
+
+msgid "FeatureFlags|Description"
+msgstr ""
+
+msgid "FeatureFlags|Edit %{feature_flag_name}"
+msgstr ""
+
+msgid "FeatureFlags|Edit Feature Flag"
+msgstr ""
+
+msgid "FeatureFlags|Feature Flag"
+msgstr ""
+
+msgid "FeatureFlags|Feature flag"
+msgstr ""
+
+msgid "FeatureFlags|Feature flag %{feature_flag_name} will be removed. Are you sure?"
+msgstr ""
+
+msgid "FeatureFlags|Feature flags allow you to configure your code into different flavors by dynamically toggling certain functionality."
+msgstr ""
+
+msgid "FeatureFlags|Get started with feature flags"
+msgstr ""
+
+msgid "FeatureFlags|Inactive"
+msgstr ""
+
+msgid "FeatureFlags|Install a %{docs_link_start}compatible client library%{docs_link_end} and specify the API URL, application name, and instance ID during the configuration setup."
+msgstr ""
+
+msgid "FeatureFlags|Instance ID"
+msgstr ""
+
+msgid "FeatureFlags|More information"
+msgstr ""
+
+msgid "FeatureFlags|Name"
+msgstr ""
+
+msgid "FeatureFlags|New"
+msgstr ""
+
+msgid "FeatureFlags|New Feature Flag"
+msgstr ""
+
+msgid "FeatureFlags|Save changes"
+msgstr ""
+
+msgid "FeatureFlags|Status"
+msgstr ""
+
 msgid "Feb"
 msgstr ""
 

yarn.lock

@@ -180,10 +180,13 @@
     lodash "^4.17.10"
     to-fast-properties "^2.0.0"
 
-"@gitlab-org/gitlab-svgs@^1.23.0", "@gitlab-org/gitlab-svgs@^1.29.0":
-  version "1.29.0"
-  resolved "https://registry.yarnpkg.com/@gitlab-org/gitlab-svgs/-/gitlab-svgs-1.29.0.tgz#03b65b513f9099bbda6ecf94d673a2952f8c6c70"
-  integrity sha512-sCl6nP3ph36+8P3nrw9VanAR648rgOUEBlEoLPHkhKm79xB1dUkXGBtI0uaSJVgbJx40M1/Ts8HSdMv+PF3EIg==
+"@gitlab-org/gitlab-svgs@^1.29.0":
+  version "1.30.0"
+  resolved "https://registry.yarnpkg.com/@gitlab-org/gitlab-svgs/-/gitlab-svgs-1.30.0.tgz#72dca2fb67bafb3c975a322dc6406aaa29aed86c"
+
+"@gitlab-org/gitlab-svgs@^1.30.0":
+  version "1.31.0"
+  resolved "https://registry.yarnpkg.com/@gitlab-org/gitlab-svgs/-/gitlab-svgs-1.31.0.tgz#495b074669f93af40e34f9978ce887773dea470a"
 
 "@gitlab-org/gitlab-ui@^1.7.1":
   version "1.7.1"