Expose CloudPlatform::Client#projects_list as GcpController#list_projects

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_api, except: [:login, :list_projects]
   before_action :authorize_google_project_billing, only: [:new, :create]
   before_action :authorize_create_cluster!, only: [:new, :create]
   before_action :verify_billing, only: [:create]
@@ -35,6 +35,13 @@ class Projects::Clusters::GcpController < Projects::ApplicationController
     end
   end
 
+  def list_projects
+    projects = GoogleApi::CloudPlatform::Client.new(token_in_session, nil).projects_list
+    respond_to do |format|
+      format.json { render status: :ok, json: { projects: projects } }
+    end
+  end
+
   private
 
   def verify_billing

config/routes/project.rb

@@ -200,6 +200,7 @@ constraints(::Constraints::ProjectUrlConstrainer.new) do
 
             get '/gcp/new', to: 'clusters/gcp#new'
             get '/gcp/login', to: 'clusters/gcp#login'
+            get '/gcp/list_projects', to: 'clusters/gcp#list_projects'
             post '/gcp', to: 'clusters/gcp#create'
           end
         end

spec/controllers/projects/clusters/gcp_controller_spec.rb

@@ -199,4 +199,34 @@ describe Projects::Clusters::GcpController do
       post :create, params.merge(namespace_id: project.namespace, project_id: project)
     end
   end
+
+  describe 'GET list_projects' do
+    describe 'functionality' do
+      let(:user) { create(:user) }
+      let(:api_response) { [project_id: 'test-project-1234'] }
+
+      before do
+        project.add_master(user)
+        sign_in(user)
+
+        allow_any_instance_of(GoogleApi::CloudPlatform::Client).to receive(:projects_list).and_return(api_response)
+      end
+
+      it 'calls the Google Cloud Platform projects_list' do
+        expect_any_instance_of(GoogleApi::CloudPlatform::Client).to receive(:projects_list)
+
+        go
+      end
+
+      it 'renders the response as json' do
+        go
+
+        expect(response.body).to eq({ projects: api_response }.to_json)
+      end
+    end
+
+    def go
+      get :list_projects, namespace_id: project.namespace, project_id: project, format: :json
+    end
+  end
 end