Fix after code review

db/schema.rb

@@ -1959,7 +1959,7 @@ ActiveRecord::Schema.define(version: 20180926140319) do
     t.string "token", null: false
   end
 
-  add_index "operations_feature_flags_clients", ["token"], name: "index_operations_feature_flags_clients_on_token", unique: true, using: :btree
+  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

ee/app/helpers/feature_flags_helper.rb

 # frozen_string_literal: true
 
 module FeatureFlagsHelper
+  include ::API::Helpers::RelatedResourcesHelpers
+
   def unleash_api_url(project)
-    "#{root_url(only_path: false)}api/v4/feature_flags/unleash/#{project.id}"
+    expose_url(api_v4_feature_flags_unleash_path(project_id: project.id))
   end
 
-  def unleash_api_instanceid(project)
+  def unleash_api_instance_id(project)
     project.feature_flags_client_token
   end
 end

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

@@ -33,7 +33,7 @@
             = label_tag :instance_id, s_('FeatureFlags|Instance ID'), class: 'label-bold'
             .input-group
               = text_field_tag :instance_id,
-                unleash_api_instanceid(@project),
+                unleash_api_instance_id(@project),
                 readonly: true,
                 class: "form-control js-select-on-focus"
               %span.input-group-append

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

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

ee/db/migrate/20180626171125_add_feature_flags_to_projects.rb

@@ -23,7 +23,7 @@ class AddFeatureFlagsToProjects < ActiveRecord::Migration
       t.integer :project_id, null: false
       t.string :token, null: false
 
-      t.index :token, unique: true
+      t.index [:project_id, :token], unique: true
 
       t.foreign_key :projects, column: :project_id, on_delete: :cascade
     end

ee/lib/api/unleash.rb

@@ -6,14 +6,19 @@ module API
       resource :unleash, requirements: API::PROJECT_ENDPOINT_REQUIREMENTS do
         params do
           requires :project_id, type: String, desc: 'The ID of a project'
-          optional :instanceid, type: String, desc: 'The Instance ID of Unleash Client'
+          optional :instance_id, type: String, desc: 'The Instance ID of Unleash Client'
         end
         route_param :project_id do
           before do
-            authorize_by_unleash_instanceid!
+            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
@@ -36,13 +41,13 @@ module API
         @project ||= find_project(params[:project_id])
       end
 
-      def unleash_instanceid
-        params[:instanceid] || env['HTTP_UNLEASH_INSTANCEID']
+      def unleash_instance_id
+        params[:instance_id] || env['HTTP_UNLEASH_INSTANCEID']
       end
 
-      def authorize_by_unleash_instanceid!
+      def authorize_by_unleash_instance_id!
         unauthorized! unless Operations::FeatureFlagsClient
-          .find_for_project_and_token(project, unleash_instanceid)
+          .find_for_project_and_token(project, unleash_instance_id)
       end
 
       def authorize_feature_flags_feature!

ee/spec/controllers/projects/feature_flags_controller_spec.rb

 require 'spec_helper'
 
 describe Projects::FeatureFlagsController do
-  include Rails.application.routes.url_helpers
+  include Gitlab::Routing
 
   set(:user) { create(:user) }
   set(:project) { create(:project) }

ee/spec/helpers/feature_flags_helper_spec.rb

@@ -9,8 +9,8 @@ describe FeatureFlagsHelper do
     it { is_expected.to end_with("/api/v4/feature_flags/unleash/#{project.id}") }
   end
 
-  context '#unleash_api_instanceid' do
-    subject { helper.unleash_api_instanceid(project) }
+  context '#unleash_api_instance_id' do
+    subject { helper.unleash_api_instance_id(project) }
 
     it { is_expected.not_to be_empty }
   end

ee/spec/requests/api/unleash_spec.rb

@@ -12,9 +12,9 @@ describe API::Unleash do
   end
 
   shared_examples 'authenticated request' do
-    context 'when using instanceid' do
+    context 'when using instance id' do
       let(:client) { create(:operations_feature_flags_client, project: project) }
-      let(:params) { { instanceid: client.token } }
+      let(:params) { { instance_id: client.token } }
 
       it 'responds with OK' do
         subject
@@ -44,8 +44,8 @@ describe API::Unleash do
       end
     end
 
-    context 'when using bogus instanceid' do
-      let(:params) { { instanceid: 'token' } }
+    context 'when using bogus instance id' do
+      let(:params) { { instance_id: 'token' } }
 
       it 'responds with unauthorized' do
         subject
@@ -56,7 +56,7 @@ describe API::Unleash do
 
     context 'when using not existing project' do
       let(:project_id) { -5000 }
-      let(:params) { { instanceid: 'token' } }
+      let(:params) { { instance_id: 'token' } }
 
       it 'responds with unauthorized' do
         subject