Fix the GCP integration tests

spring-cloud-function-samples/function-sample-gcp-http/pom.xml

@@ -47,7 +47,12 @@
 			<artifactId>assertj-core</artifactId>
 			<scope>test</scope>
 		</dependency>
-
+		<dependency>
+			<groupId>com.google.cloud.functions.invoker</groupId>
+			<artifactId>java-function-invoker</artifactId>
+			<version>1.0.0-alpha-2-rc5</version>
+			<scope>test</scope>
+		</dependency>
 	</dependencies>
 
 	<build>

spring-cloud-function-samples/function-sample-gcp-http/src/test/java/com/example/FunctionSampleGcpIntegrationTest.java

@@ -16,77 +16,23 @@
 
 package com.example;
 
-import java.io.BufferedReader;
 import java.io.IOException;
-import java.io.InputStream;
-import java.io.InputStreamReader;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.Executors;
-import java.util.concurrent.TimeUnit;
 
-import org.junit.Ignore;
 import org.junit.Test;
 
 import org.springframework.boot.test.web.client.TestRestTemplate;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.fail;
 
 public class FunctionSampleGcpIntegrationTest {
 
 	private TestRestTemplate rest = new TestRestTemplate();
 
-	private CountDownLatch startedSuccessfully = new CountDownLatch(1);
-
 	@Test
-	@Ignore
+	public void testSample() throws IOException, InterruptedException {
-	public void testSample() throws IOException {
+		try (LocalServerTestSupport.ServerProcess process = LocalServerTestSupport.startServer(CloudFunctionMain.class)) {
-		Process process = new ProcessBuilder("./../../mvnw", "function:run").start();
+			String result = rest.postForObject("http://localhost:8080/", "Hello", String.class);
-
+			assertThat(result).isEqualTo("\"HELLO\"");
-		try {
-			Executors.defaultThreadFactory().newThread(new OutputCapture(process.getErrorStream())).start();
-			Executors.defaultThreadFactory().newThread(new OutputCapture(process.getInputStream())).start();
-
-			if (startedSuccessfully.await(10, TimeUnit.SECONDS)) {
-				String result = rest.postForObject("http://localhost:8080/", "Hello", String.class);
-				assertThat(result).isEqualTo("\"HELLO\"");
-			}
-			else {
-				fail("Failed to start the function.");
-			}
-		}
-		catch (InterruptedException e) {
-			e.printStackTrace();
-		}
-		finally {
-			process.destroy();
 		}
 	}
-
-	class OutputCapture implements Runnable {
-
-		private InputStream inputStream;
-
-		OutputCapture(InputStream inputStream) {
-			this.inputStream = inputStream;
-		}
-
-		@Override
-		public void run() {
-			try (BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream))) {
-				String line;
-				while ((line = reader.readLine()) != null) {
-					System.out.println(line);
-					if (line.equals("INFO: URL: http://localhost:8080/")) {
-						startedSuccessfully.countDown();
-					}
-				}
-			}
-			catch (IOException e) {
-				e.printStackTrace();
-			}
-		}
-
-	}
-
 }

spring-cloud-function-samples/function-sample-gcp-http/src/test/java/com/example/LocalServerTestSupport.java

@@ -0,0 +1,139 @@
+/*
+ * Copyright 2020-2020 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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 com.example;
+
+import java.io.*;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import com.google.cloud.functions.invoker.runner.Invoker;
+
+import org.springframework.cloud.function.adapter.gcp.GcfJarLauncher;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Test support class for running tests on the local Cloud Function server.
+ *
+ * @author Daniel Zou
+ * @author Mike Eltsufin
+ */
+final public class LocalServerTestSupport {
+
+	private static final ExecutorService EXECUTOR = Executors.newCachedThreadPool();
+
+	private static final String SERVER_READY_STRING = "Started ServerConnector";
+
+	private static AtomicInteger nextPort = new AtomicInteger(8080);
+
+	private LocalServerTestSupport() {
+	}
+
+	public static ServerProcess startServer(Class<?> springApplicationMainClass)
+			throws InterruptedException, IOException {
+
+		// Get the Java class path.
+		String myClassPath = System.getProperty("java.class.path");
+		assertThat(myClassPath).isNotNull();
+
+		// Setup the Java Process command line string
+		List<String> command = Arrays.asList(getJavaCommand(), "-classpath", myClassPath, Invoker.class.getName());
+		ProcessBuilder processBuilder = new ProcessBuilder().command(command).redirectErrorStream(true);
+
+		// Set environment variables.
+		Map<String, String> environment = new HashMap<>();
+		environment.put("PORT", String.valueOf(nextPort.getAndIncrement()));
+		environment.put("K_SERVICE", "test-function");
+		environment.put("FUNCTION_SIGNATURE_TYPE", "http");
+		environment.put("FUNCTION_TARGET", GcfJarLauncher.class.getCanonicalName());
+		environment.put("MAIN_CLASS", springApplicationMainClass.getCanonicalName());
+		processBuilder.environment().putAll(environment);
+
+		// Start the process and monitor the output logs in a separate thread.
+		// Once the SERVER_READY_STRING is found in the logs, we know we are ready.
+		Process serverProcess = processBuilder.start();
+		CountDownLatch ready = new CountDownLatch(1);
+
+		EXECUTOR.submit(() -> monitorOutput(serverProcess.getInputStream(), ready));
+		boolean serverReady = ready.await(5, TimeUnit.SECONDS);
+		if (!serverReady) {
+			serverProcess.destroy();
+			throw new AssertionError("Server never became ready");
+		}
+
+		return new ServerProcess(serverProcess);
+	}
+
+	private static void monitorOutput(InputStream processOutput, CountDownLatch ready) {
+		try (BufferedReader reader = new BufferedReader(new InputStreamReader(processOutput))) {
+			String line;
+			while ((line = reader.readLine()) != null) {
+				if (line.contains(SERVER_READY_STRING)) {
+					ready.countDown();
+				}
+
+				System.out.println(line);
+
+				if (line.contains("WARNING")) {
+					throw new AssertionError("Found warning in server output:\n" + line);
+				}
+			}
+		}
+		catch (IOException e) {
+			throw new UncheckedIOException(e);
+		}
+	}
+
+	/**
+	 * Returns the path to the java executable.
+	 */
+	private static String getJavaCommand() {
+		File javaHome = new File(System.getProperty("java.home"));
+		assertThat(javaHome.exists()).isTrue();
+
+		File javaBin = new File(javaHome, "bin");
+		File javaCommand = new File(javaBin, "java");
+		assertThat(javaCommand.exists()).isTrue();
+
+		return javaCommand.toString();
+	}
+
+	static class ServerProcess implements AutoCloseable {
+
+		private final Process process;
+
+		ServerProcess(Process process) {
+			this.process = process;
+		}
+
+		Process process() {
+			return process;
+		}
+
+		@Override
+		public void close() {
+			process().destroy();
+		}
+	}
+}