Add check step for creating GCP clusters

app/controllers/projects/clusters/gcp_controller.rb

 class Projects::Clusters::GcpController < Projects::ApplicationController
   before_action :authorize_read_cluster!
   before_action :authorize_google_api, except: [:login]
+  before_action :authorize_google_project_billing, only: [:check]
   before_action :authorize_create_cluster!, only: [:new, :create]
+  STATUS_POLLING_INTERVAL = 10_000
+
   def login
     begin
-      state = generate_session_key_redirect(gcp_new_namespace_project_clusters_path.to_s)
+      state = generate_session_key_redirect(gcp_check_namespace_project_clusters_path.to_s)
       @authorize_url = GoogleApi::CloudPlatform::Client.new(
         nil, callback_google_api_auth_url,
@@ -15,6 +18,18 @@ class Projects::Clusters::GcpController < Projects::ApplicationController
     end
   end
+  def check
+    respond_to do |format|
+      format.json do
+        Gitlab::PollingInterval.set_header(response, interval: STATUS_POLLING_INTERVAL)
+
+        Gitlab::Redis::SharedState.with do |redis|
+          render json: { billing: redis.get(CheckGcpProjectBillingWorker.redis_shared_state_key_for(token_in_session)) }
+        end
+      end
+    end
+  end
+
   def new
     @cluster = ::Clusters::Cluster.new.tap do |cluster|
       cluster.build_provider_gcp
@@ -57,6 +72,14 @@ class Projects::Clusters::GcpController < Projects::ApplicationController
     end
   end
+  def authorize_google_project_billing
+    Gitlab::Redis::SharedState.with do |redis|
+      unless redis.get(CheckGcpProjectBillingWorker.redis_shared_state_key_for(token_in_session)) == 'true'
+        CheckGcpProjectBillingWorker.perform_async(token_in_session)
+      end
+    end
+  end
+
   def token_in_session
     @token_in_session ||=
       session[GoogleApi::CloudPlatform::Client.session_key_for_token]

app/views/projects/clusters/gcp/check.html.haml

+Hello

app/views/projects/clusters/new.html.haml

@@ -8,6 +8,6 @@
     %h4.prepend-top-0= s_('ClusterIntegration|Choose how to set up cluster integration')
     %p= s_('ClusterIntegration|Create a new cluster on Google Kubernetes Engine right from GitLab')
-    = link_to s_('ClusterIntegration|Create on GKE'), gcp_new_namespace_project_clusters_path(@project.namespace, @project), class: 'btn append-bottom-20'
+    = link_to s_('ClusterIntegration|Create on GKE'), gcp_check_namespace_project_clusters_path(@project.namespace, @project), class: 'btn append-bottom-20'
     %p= s_('ClusterIntegration|Enter the details for an existing Kubernetes cluster')
     = link_to s_('ClusterIntegration|Add an existing cluster'), user_new_namespace_project_clusters_path(@project.namespace, @project), class: 'btn append-bottom-20'

config/routes/project.rb

@@ -189,6 +189,7 @@ constraints(ProjectUrlConstrainer.new) do
             get '/user/new', to: 'clusters/user#new'
             post '/user', to: 'clusters/user#create'
+            get '/gcp/check', to: 'clusters/gcp#check'
             get '/gcp/new', to: 'clusters/gcp#new'
             get '/gcp/login', to: 'clusters/gcp#login'
             post '/gcp', to: 'clusters/gcp#create'

spec/controllers/projects/clusters/gcp_controller_spec.rb

@@ -30,7 +30,7 @@ describe Projects::Clusters::GcpController do
           go
           expect(assigns(:authorize_url)).to include(key)
-          expect(session[session_key_for_redirect_uri]).to eq(gcp_new_project_clusters_path(project))
+          expect(session[session_key_for_redirect_uri]).to eq(gcp_check_project_clusters_path(project))
         end
       end
@@ -63,6 +63,75 @@ describe Projects::Clusters::GcpController do
     end
   end
+  describe 'GET check' do
+    let(:user) { create(:user) }
+
+    before do
+      project.add_master(user)
+      sign_in(user)
+    end
+
+    describe 'functionality' do
+      context 'when redis has wanted billing status' do
+        let(:token) { 'bogustoken' }
+        before do
+          redis_double = double
+          allow(Gitlab::Redis::SharedState).to receive(:with).and_yield(redis_double)
+          allow(redis_double).to receive(:get).and_return('true')
+        end
+
+        it 'should render json with billing status' do
+          go
+
+          expect(response).to have_http_status(:ok)
+          expect(response.body).to include_json(billing: 'true')
+        end
+
+        it 'should not start worker' do
+          expect(CheckGcpProjectBillingWorker).not_to receive(:perform_async)
+
+          go
+        end
+      end
+
+      context 'when redis does not have billing status' do
+        before do
+          redis_double = double
+          allow(Gitlab::Redis::SharedState).to receive(:with).and_yield(redis_double)
+          allow(redis_double).to receive(:get).and_return(nil)
+        end
+
+        it 'should render json with null billing status' do
+          go
+
+          expect(response).to have_http_status(:ok)
+          expect(response.body).to include_json(billing: nil)
+        end
+
+        it 'should start worker' do
+          expect(CheckGcpProjectBillingWorker).to receive(:perform_async)
+
+          go
+        end
+      end
+    end
+
+    describe 'security' do
+      it { expect { go }.to be_allowed_for(:admin) }
+      it { expect { go }.to be_allowed_for(:owner).of(project) }
+      it { expect { go }.to be_allowed_for(:master).of(project) }
+      it { expect { go }.to be_denied_for(:developer).of(project) }
+      it { expect { go }.to be_denied_for(:reporter).of(project) }
+      it { expect { go }.to be_denied_for(:guest).of(project) }
+      it { expect { go }.to be_denied_for(:user) }
+      it { expect { go }.to be_denied_for(:external) }
+    end
+
+    def go
+      get :check, namespace_id: project.namespace, project_id: project, format: :json
+    end
+  end
+
   describe 'GET new' do
     describe 'functionality' do
       let(:user) { create(:user) }