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.

Directory task-handler/ is the main App Engine app. This app serves as an endpoint to receive App Engine task attempts.

• Set up a Google Cloud Project and enable billing.
• Enable the Cloud Tasks API.
• Download and install the Cloud SDK.
• Download and install Maven.
• Set up Google Application Credentials.

To create a queue using the Cloud SDK, use the following gcloud command:

gcloud tasks queues create my-appengine-queue

Note: A newly created queue will route to the default App Engine service and version unless configured to do otherwise.

Using Maven and the App Engine Plugin & Maven Plugin Goals and Parameters

• Copy the sample apps to your local machine:

git clone https://github.com/GoogleCloudPlatform/java-docs-samples

• Move into the task-handler directory:

cd java-docs-samples/appengine-java11/task-handler

• Deploy the app

gcloud app deploy

• Move into the appengine-java11/tasks directory and compile the app:

cd ../tasks
mvn package

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 tasks queues list.

export QUEUE_ID="my-appengine-queue"

And finally the location ID, which can be discovered with gcloud 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="us-central1"

Create a task, targeted at the /tasks/create endpoint, with a payload specified:

mvn exec:java -Dexec.mainClass="com.example.task.CreateTask"

The App Engine app serves as a target for the push requests. It has an endpoint /tasks/create that reads the payload (i.e., the request body) of the HTTP POST request and logs it. The log output can be viewed with Stackdriver Logging.