Add runner quota information for job API

Send new property `quota` under the `runner` property, with the quota
information when the runner is of type `instance`

Add new JSON schema for ee only

Add new job_controller_spec.rb for ee only

closes https://gitlab.com/gitlab-org/gitlab-ee/issues/7441

app/serializers/build_details_entity.rb

@@ -5,6 +5,8 @@ class BuildDetailsEntity < JobEntity
   include RequestAwareEntity
   include CiStatusHelper
 
+  prepend ::EE::BuildDetailEntity
+
   expose :coverage, :erased_at, :duration
   expose :tag_list, as: :tags
   expose :user, using: UserEntity

ee/app/serializers/ee/build_detail_entity.rb

+# frozen_string_literal: true
+
+module EE
+  module BuildDetailEntity
+    extend ActiveSupport::Concern
+
+    prepended do
+      expose :runners do
+        expose :quota, if: -> (*) { project.shared_runners_minutes_limit_enabled? } do
+          expose :used do |runner|
+            project.shared_runners_minutes.to_i
+          end
+
+          expose :limit do |runner|
+            project.actual_shared_runners_minutes_limit.to_i
+          end
+        end
+      end
+    end
+  end
+end

ee/changelogs/unreleased/7441-add-shared-runner-quota-information-in-job-api.yml

+---
+title: Add runner quota information to job API
+merge_request: 7233
+author:
+type: other

ee/spec/controllers/projects/jobs_controller_spec.rb

+# coding: utf-8
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Projects::JobsController, :clean_gitlab_redis_shared_state do
+  include ApiHelpers
+  include HttpIOHelpers
+
+  let(:user) { create(:user) }
+
+  before do
+    stub_not_protect_default_branch
+  end
+
+  describe 'GET show' do
+    context 'when requesting JSON' do
+      context 'with shared runner that has quota' do
+        let(:project) { create(:project, :private, shared_runners_enabled: true) }
+        let(:merge_request) { create(:merge_request, source_project: project) }
+        let(:pipeline) { create(:ci_pipeline, project: project) }
+        let(:runner) { create(:ci_runner, :instance, description: 'Shared runner') }
+        let(:job) { create(:ci_build, :success, :artifacts, pipeline: pipeline, runner: runner) }
+
+        before do
+          project.add_developer(user)
+          sign_in(user)
+
+          allow_any_instance_of(Ci::Build).to receive(:merge_request).and_return(merge_request)
+
+          stub_application_setting(shared_runners_minutes: 2)
+
+          get_show(id: job.id, format: :json)
+        end
+
+        it 'exposes quota information' do
+          expect(response).to have_gitlab_http_status(:ok)
+          expect(response).to match_response_schema('job/job_details', dir: 'ee')
+          expect(json_response['runners']['quota']['used']).to eq 0
+          expect(json_response['runners']['quota']['limit']).to eq 2
+        end
+      end
+
+      context 'when shared runner has no quota' do
+        let(:project) { create(:project, :private, shared_runners_enabled: true) }
+        let(:merge_request) { create(:merge_request, source_project: project) }
+        let(:pipeline) { create(:ci_pipeline, project: project) }
+        let(:runner) { create(:ci_runner, :instance, description: 'Shared runner') }
+        let(:job) { create(:ci_build, :success, :artifacts, pipeline: pipeline, runner: runner) }
+
+        before do
+          project.add_developer(user)
+          sign_in(user)
+
+          allow_any_instance_of(Ci::Build).to receive(:merge_request).and_return(merge_request)
+
+          stub_application_setting(shared_runners_minutes: 0)
+
+          get_show(id: job.id, format: :json)
+        end
+
+        it 'does not exposes quota information' do
+          expect(response).to have_gitlab_http_status(:ok)
+          expect(response).to match_response_schema('job/job_details', dir: 'ee')
+          expect(json_response['runners']).not_to have_key('quota')
+        end
+      end
+
+      context 'when project is public' do
+        let(:project) { create(:project, :public, shared_runners_enabled: true) }
+        let(:merge_request) { create(:merge_request, source_project: project) }
+        let(:pipeline) { create(:ci_pipeline, project: project) }
+        let(:runner) { create(:ci_runner, :instance, description: 'Shared runner') }
+        let(:job) { create(:ci_build, :success, :artifacts, pipeline: pipeline, runner: runner) }
+
+        before do
+          project.add_developer(user)
+          sign_in(user)
+
+          allow_any_instance_of(Ci::Build).to receive(:merge_request).and_return(merge_request)
+
+          stub_application_setting(shared_runners_minutes: 2)
+
+          get_show(id: job.id, format: :json)
+        end
+
+        it 'does not exposes quota information' do
+          expect(response).to have_gitlab_http_status(:ok)
+          expect(response).to match_response_schema('job/job_details', dir: 'ee')
+          expect(json_response['runners']).not_to have_key('quota')
+        end
+      end
+    end
+
+    private
+
+    def get_show(**extra_params)
+      params = {
+          namespace_id: project.namespace.to_param,
+          project_id: project
+      }
+
+      get :show, params.merge(extra_params)
+    end
+  end
+end

ee/spec/fixtures/api/schemas/job/job_details.json

+{
+  "allOf": [
+    { "$ref": "../../../../../../spec/fixtures/api/schemas/job/job_details.json" },
+    {
+      "properties": {
+        "runner": { "$ref": "runner.json" }
+      }
+    }
+  ]
+}

ee/spec/fixtures/api/schemas/job/runner.json

+{
+  "type": "object",
+  "properties": {
+    "quota": {
+      "description": "Quota information that is only shown for shared runners.",
+      "type": "object",
+      "required": [
+        "used",
+        "limit"
+      ],
+      "properties": {
+        "used": { "type": "integer" },
+        "limit": { "type": "integer" }
+      },
+      "additionalProperties": false
+    }
+  }
+}