[Cloud Tasks] Add HTTP push queue sample (#1355)

* Add HTTP sample

* Fix linting

* remove CLI

* Move http sample

* Fix pom.xml

* Update pom and linting

* Update tasks version

appengine-java8/tasks/README.md

@@ -69,12 +69,15 @@ location is "us-central1").
 export LOCATION_ID=<YOUR_ZONE>
 ```
 
+### Using App Engine Queues
 Create a task, targeted at the `/tasks/create` endpoint, with a payload specified:
 
 ```
 mvn exec:java -Dexec.mainClass="com.example.task.CreateTask" \
     -Dexec.args="--project-id $GOOGLE_CLOUD_PROJECT \
-    --queue $QUEUE_ID --location $LOCATION_ID --payload hello"
+    --queue $QUEUE_ID \
+    --location $LOCATION_ID \
+    --payload hello"
 ```
 
 The App Engine app serves as a target for the push requests. It has an

appengine-java8/tasks/pom.xml

@@ -52,7 +52,7 @@ Copyright 2018 Google LLC
     <dependency>
       <groupId>com.google.cloud</groupId>
       <artifactId>google-cloud-tasks</artifactId>
-      <version>0.86.0-beta</version>
+      <version>0.88.0-beta</version>
     </dependency>
     <dependency>
       <groupId>commons-cli</groupId>

appengine-java8/tasks/src/main/java/com/example/task/CreateTask.java

@@ -161,8 +161,8 @@ private static void printUsage(Options options) {
     HelpFormatter formatter = new HelpFormatter();
     formatter.printHelp(
         "client",
-        "A simple Cloud Tasks command line client that triggers a call to an AppEngine "
-            + "endpoint.",
+        "A simple Cloud Tasks command line client that creates a task with an "
+            + "App Engine endpoint.",
         options, "", true);
     throw new RuntimeException();
   }

appengine-java8/tasks/src/main/java/com/example/task/TaskServlet.java

@@ -38,7 +38,7 @@ public void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOEx
     String body = req.getReader()
         .lines()
         .reduce("", (accumulator, actual) -> accumulator + actual);
-        
+
     if (!body.isEmpty()) {
       log.info("Request payload: " + body);
       String output = String.format("Received task with payload %s", body);

tasks/README.md

@@ -0,0 +1,85 @@
+# Google Cloud Tasks App Engine Queue Samples
+
+Sample command-line program for interacting with the Cloud Tasks API
+using App Engine queues.
+
+App Engine queues push tasks to an App Engine HTTP target. This directory
+contains both the App Engine app to deploy, as well as the snippets to run
+locally to push tasks to it, which could also be called on App Engine.
+
+`CreateTask.java` is a simple command-line program to create
+tasks to be pushed to the App Engine app.
+
+`TaskServlet.java` is the main App Engine app. This app serves as an endpoint to receive
+App Engine task attempts.
+
+
+## Initial Setup
+
+ * Set up a Google Cloud Project and enable billing.
+ * Enable the
+ [Cloud Tasks API](https://console.cloud.google.com/launcher/details/google/cloudtasks.googleapis.com).
+ * Download and install the [Cloud SDK](https://cloud.google.com/sdk).
+ * Download and install [Maven](http://maven.apache.org/install.html).
+ * Set up [Google Application Credentials](https://cloud.google.com/docs/authentication/getting-started).
+
+## Creating a queue
+
+To create a queue using the Cloud SDK, use the following gcloud command:
+
+```
+gcloud beta tasks queues create-app-engine-queue my-appengine-queue
+```
+
+Note: A newly created queue will route to the default App Engine service and
+version unless configured to do otherwise.
+
+## Deploying the App Engine app
+[Using Maven and the App Engine Plugin](https://cloud.google.com/appengine/docs/flexible/java/using-maven)
+& [Maven Plugin Goals and Parameters](https://cloud.google.com/appengine/docs/flexible/java/maven-reference)
+
+```
+mvn appengine:deploy
+```
+
+## Run the Sample Using the Command Line
+
+Set environment variables:
+
+First, your project ID:
+
+```
+export GOOGLE_CLOUD_PROJECT=<YOUR_GOOGLE_CLOUD_PROJECT>
+```
+
+Then the queue ID, as specified at queue creation time. Queue IDs already
+created can be listed with `gcloud beta tasks queues list`.
+
+```
+export QUEUE_ID=my-appengine-queue
+```
+
+And finally the location ID, which can be discovered with
+`gcloud beta tasks queues describe $QUEUE_ID`, with the location embedded in
+the "name" value (for instance, if the name is
+"projects/my-project/locations/us-central1/queues/my-appengine-queue", then the
+location is "us-central1").
+
+```
+export LOCATION_ID=<YOUR_ZONE>
+```
+
+### Using HTTP Push Queues
+
+Set an environment variable for the endpoint to your task handler. This is an
+example url to send requests to the App Engine task handler:
+```
+export URL=https://${PROJECT_ID}.appspot.com/tasks/create
+```
+
+Running the sample will create a task and send the task to the specific URL
+endpoint, with a payload specified:
+
+```
+mvn exec:java -Dexec.mainClass="com.example.task.CreateHttpTask"
+```

tasks/pom.xml

@@ -0,0 +1,64 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+Copyright 2018 Google LLC
+
+ 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.
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <packaging>war</packaging>
+  <version>1.0-SNAPSHOT</version>
+  <groupId>com.example.task</groupId>
+  <artifactId>tasks-samples</artifactId>
+
+  <!--
+    The parent pom defines common style checks and testing strategies for our samples.
+    Removing or replacing it should not affect the execution of the samples in anyway.
+  -->
+  <parent>
+    <groupId>com.google.cloud.samples</groupId>
+    <artifactId>shared-configuration</artifactId>
+    <version>1.0.11</version>
+    <relativePath></relativePath>
+  </parent>
+
+  <properties>
+    <maven.compiler.target>1.8</maven.compiler.target>
+    <maven.compiler.source>1.8</maven.compiler.source>
+    <failOnMissingWebXml>false</failOnMissingWebXml>
+  </properties>
+
+  <dependencies>
+    <!-- Compile/runtime dependencies -->
+    <dependency>
+      <groupId>com.google.cloud</groupId>
+      <artifactId>google-cloud-tasks</artifactId>
+      <version>0.88.0-beta</version>
+    </dependency>
+  </dependencies>
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>exec-maven-plugin</artifactId>
+        <version>1.4.0</version>
+        <configuration>
+          <mainClass>com.example.task.CreateHttpTask</mainClass>
+          <cleanupDaemonThreads>false</cleanupDaemonThreads>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+</project>

tasks/src/main/java/com/example/task/CreateHttpTask.java

@@ -0,0 +1,64 @@
+/*
+ * Copyright 2018 Google LLC
+ *
+ * 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 com.example.task;
+
+// [START cloud_tasks_create_http_task]
+import com.google.cloud.tasks.v2beta3.CloudTasksClient;
+import com.google.cloud.tasks.v2beta3.HttpMethod;
+import com.google.cloud.tasks.v2beta3.HttpRequest;
+import com.google.cloud.tasks.v2beta3.QueueName;
+import com.google.cloud.tasks.v2beta3.Task;
+import com.google.protobuf.ByteString;
+import java.nio.charset.Charset;
+
+public class CreateHttpTask {
+
+  public static void main(String[] args) throws Exception {
+    String projectId = System.getenv("PROJECT_ID");
+    String queueName = System.getenv("QUEUE_ID");
+    String location = System.getenv("LOCATION_ID");
+    String url = System.getenv("URL");
+
+    // Instantiates a client.
+    try (CloudTasksClient client = CloudTasksClient.create()) {
+      // Variables provided by the system variables.
+      // projectId = "my-project-id";
+      // queueName = "my-appengine-queue";
+      // location = "us-central1";
+      // url = "https://<project-id>.appspot.com/tasks/create";
+      String payload = "hello";
+
+      // Construct the fully qualified queue name.
+      String queuePath = QueueName.of(projectId, location, queueName).toString();
+
+      // Construct the task body.
+      Task.Builder taskBuilder =
+          Task.newBuilder()
+              .setHttpRequest(
+                  HttpRequest.newBuilder()
+                      .setBody(ByteString.copyFrom(payload, Charset.defaultCharset()))
+                      .setUrl(url)
+                      .setHttpMethod(HttpMethod.POST)
+                      .build());
+
+      // Send create task request.
+      Task task = client.createTask(queuePath, taskBuilder.build());
+      System.out.println("Task created: " + task.getName());
+    }
+  }
+}
+// [END cloud_tasks_create_http_task]