Respond with 404 when metrics are not enabled or deployment_metrics is not implemented

app/controllers/projects/deployments_controller.rb

@@ -11,13 +11,15 @@ class Projects::DeploymentsController < Projects::ApplicationController
   end
 
   def metrics
+    return render_404 unless deployment.has_metrics?
     @metrics = deployment.metrics
-
     if @metrics&.any?
       render json: @metrics, status: :ok
     else
       head :no_content
     end
+  rescue NotImplementedError
+    render_404
   end
 
   private

spec/controllers/projects/deployments_controller_spec.rb

@@ -42,6 +42,22 @@ describe Projects::DeploymentsController do
     before do
       allow(controller).to receive(:deployment).and_return(deployment)
     end
+    context 'when metrics are disabled' do
+      before do
+        allow(deployment).to receive(:has_metrics?).and_return false
+      end
+
+      it 'responds with not found' do
+        get :metrics, deployment_params(id: deployment.id)
+
+        expect(response).to be_not_found
+      end
+    end
+
+    context 'when metrics are enabled' do
+      before do
+        allow(deployment).to receive(:has_metrics?).and_return true
+      end
 
       context 'when environment has no metrics' do
         before do
@@ -77,6 +93,19 @@ describe Projects::DeploymentsController do
           expect(json_response['last_update']).to eq(42)
         end
       end
+
+      context 'when metrics service does not implement deployment metrics' do
+        before do
+          allow(deployment).to receive(:metrics).and_raise(NotImplementedError)
+        end
+
+        it 'responds with not found' do
+          get :metrics, deployment_params(id: deployment.id)
+
+          expect(response).to be_not_found
+        end
+      end
+    end
   end
 
   def deployment_params(opts = {})