Add end-to-end code to run Beam template from App Engine

This serves as proof-of-concept to verify we can use Beam for our invoice generation use case. Namely, it checks that we can:
- Deploy a Beam template to GCS
- Read from Bigquery within the template
- Run the template from App Engine

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=175755390

javatests/google/registry/billing/GenerateInvoicesActionTest.java

@@ -0,0 +1,88 @@
+// Copyright 2017 The Nomulus Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package google.registry.billing;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.Matchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import com.google.api.services.dataflow.Dataflow;
+import com.google.api.services.dataflow.Dataflow.Projects;
+import com.google.api.services.dataflow.Dataflow.Projects.Templates;
+import com.google.api.services.dataflow.Dataflow.Projects.Templates.Launch;
+import com.google.api.services.dataflow.model.Job;
+import com.google.api.services.dataflow.model.LaunchTemplateParameters;
+import com.google.api.services.dataflow.model.LaunchTemplateResponse;
+import com.google.api.services.dataflow.model.RuntimeEnvironment;
+import google.registry.testing.FakeResponse;
+import java.io.IOException;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Unit tests for {@link GenerateInvoicesAction}. */
+@RunWith(JUnit4.class)
+public class GenerateInvoicesActionTest {
+
+  Dataflow dataflow = mock(Dataflow.class);
+  Projects projects = mock(Projects.class);
+  Templates templates = mock(Templates.class);
+  Launch launch = mock(Launch.class);
+  GenerateInvoicesAction action;
+  FakeResponse response = new FakeResponse();
+
+  @Before
+  public void initializeObjects() throws Exception {
+    when(dataflow.projects()).thenReturn(projects);
+    when(projects.templates()).thenReturn(templates);
+    when(templates.launch(any(String.class), any(LaunchTemplateParameters.class)))
+        .thenReturn(launch);
+    when(launch.setGcsPath(any(String.class))).thenReturn(launch);
+    when(launch.execute()).thenReturn(new LaunchTemplateResponse().setJob(new Job()));
+
+    action = new GenerateInvoicesAction();
+    action.dataflow = dataflow;
+    action.response = response;
+    action.projectId = "test-project";
+    action.beamBucketUrl = "gs://test-project-beam";
+  }
+
+  @Test
+  public void testLaunchTemplateJob() throws Exception {
+    action.run();
+    LaunchTemplateParameters expectedParams =
+        new LaunchTemplateParameters()
+            .setJobName("test-bigquerytemplate1")
+            .setEnvironment(
+                new RuntimeEnvironment()
+                    .setZone("us-east1-c")
+                    .setTempLocation("gs://test-project-beam/temp"));
+    verify(templates).launch("test-project", expectedParams);
+    verify(launch).setGcsPath("gs://test-project-beam/templates/bigquery1");
+    assertThat(response.getStatus()).isEqualTo(200);
+    assertThat(response.getPayload()).isEqualTo("Launched dataflow template.");
+  }
+
+  @Test
+  public void testCaughtIOException() throws Exception {
+    when(launch.execute()).thenThrow(new IOException("expected"));
+    action.run();
+    assertThat(response.getStatus()).isEqualTo(500);
+    assertThat(response.getPayload()).isEqualTo("Template launch failed: expected");
+  }
+}