Funqy Google Cloud Functions

The guide walks through quickstart code to show you how you can deploy Funqy functions to Google Cloud Functions.

This technology is considered preview.

In preview, backward compatibility and presence in the ecosystem is not guaranteed. Specific improvements might require changing configuration or APIs, and plans to become stable are under way. Feedback is welcome on our mailing list or as issues in our GitHub issue tracker.

For a full list of possible statuses, check our FAQ entry.

Prerequisites

To complete this guide, you need:

Login to Google Cloud

Login to Google Cloud is necessary for deploying the application. It can be done as follows:

gcloud auth login

The Quickstart

Clone the Git repository: git clone https://github.com/quarkusio/quarkus-quickstarts.git, or download an archive.

The solution is located in the funqy-google-cloud-functions-quickstart directory.

Creating the Maven Deployment Project

Create an application with the quarkus-funqy-google-cloud-functions extension. You can use the following Maven command to create it:

CLI
quarkus create app org.acme:funqy-google-cloud-functions \
    --extension=funqy-google-cloud-functions \
    --no-code
cd funqy-google-cloud-functions

To create a Gradle project, add the --gradle or --gradle-kotlin-dsl option.

For more information about how to install the Quarkus CLI and use it, please refer to the Quarkus CLI guide.

Maven
mvn io.quarkus.platform:quarkus-maven-plugin:2.11.2.Final:create \
    -DprojectGroupId=org.acme \
    -DprojectArtifactId=funqy-google-cloud-functions \
    -Dextensions="funqy-google-cloud-functions" \
    -DnoCode
cd funqy-google-cloud-functions

To create a Gradle project, add the -DbuildTool=gradle or -DbuildTool=gradle-kotlin-dsl option.

The Code

There is nothing special about the code and more importantly nothing Google Cloud specific. Funqy functions can be deployed to many environments and Google Cloud Functions is one of them.

Choose Your Function

Only one Funqy function can be exported per Google Cloud Functions deployment. If you only have one method annotated with @Funq in your project, then there is no worries. If you have multiple functions defined within your project, then you will need to choose the function within your Quarkus application.properties:

quarkus.funqy.export=greet

Alternatively, you can set the QUARKUS_FUNQY_EXPORT environment variable when you create the Google Cloud Function using the gcloud cli.

Build and Deploy

Build the project:

CLI
quarkus build
Maven
./mvnw clean package
Gradle
./gradlew build

This will compile and package your code.

Creating the functions

In this example, we will create two background functions and a cloud events function. Background functions allow you to react to Google Cloud events like PubSub messages, Cloud Storage events, Firestore events, …​ Cloud events functions allow you to react to supported events using the Cloud Events specification.

Quarkus supports Cloud Functions gen 1 and gen 2. For an overview of Cloud Functions gen 2 see this page on the Google Cloud Functions documentation. To use gen 2 you must use gcloud beta command and add the --gen2 parameter.
import javax.inject.Inject;

import io.cloudevents.CloudEvent;
import io.quarkus.funqy.Funq;
import io.quarkus.funqy.gcp.functions.event.PubsubMessage;
import io.quarkus.funqy.gcp.functions.event.StorageEvent;

public class GreetingFunctions {

    @Inject GreetingService service; (1)

    @Funq (2)
    public void helloPubSubWorld(PubsubMessage pubSubEvent) {
        String message = service.hello(pubSubEvent.data);
        System.out.println(pubSubEvent.messageId + " - " + message);
    }

    @Funq (3)
    public void helloGCSWorld(StorageEvent storageEvent) {
        String message = service.hello("world");
        System.out.println(storageEvent.name + " - " + message);
    }

    @Funq (4)
    public void helloCloudEvent(CloudEvent cloudEvent) {
        System.out.println("Receive event Id: " + cloudEvent.getId());
        System.out.println("Receive event Subject: " + cloudEvent.getSubject());
        System.out.println("Receive event Type: " + cloudEvent.getType());
        System.out.println("Receive event Data: " + new String(cloudEvent.getData().toBytes()));
        System.out.println("Be polite, say " + service.hello("world"));
    }
}
Function return type can also be Mutiny reactive types.
  1. Injection works inside your function.

  2. This is a background function that takes as parameter a io.quarkus.funqy.gcp.functions.event.PubsubMessage, this is a convenient class to deserialize a PubSub message.

  3. This is a background function that takes as parameter a io.quarkus.funqy.gcp.functions.event.StorageEvent, this is a convenient class to deserialize a Google Storage event.

  4. This is a cloud events functions, that takes as parameter a io.cloudevents.CloudEvent, inside it the getData() method will return the event content, storage event in this case.

we provide convenience class to deserialize common Google Cloud event inside the io.quarkus.funqy.gcp.functions.event package. They are not mandatory to use, you can use any object you want.

As our project contains multiple function, we need to specify which function needs to be deployed via the following property inside our application.properties :

quarkus.funqy.export=helloPubSubWorld

Build and Deploy to Google Cloud

To build your application, you can package your application via mvn clean package. You will have a single JAR inside the target/deployment repository that contains your classes and all your dependencies in it.

Then you will be able to use gcloud to deploy your function to Google Cloud. The gcloud command will be different depending on which event you want to trigger.

The first time you launch the gcloud functions deploy, you can have the following error message:

ERROR: (gcloud.functions.deploy) OperationError: code=7, message=Build Failed: Cloud Build has not been used in project <project_name> before or it is disabled. Enable it by visiting https://console.developers.google.com/apis/api/cloudbuild.googleapis.com/overview?project=<my-project> then retry.

This means that Cloud Build is not activated yet. To overcome this error, open the URL shown in the error, follow the instructions and then wait a few minutes before retrying the command.

Background Functions - PubSub

Use this command to deploy to Google Cloud Functions:

gcloud functions deploy quarkus-example-funky-pubsub \
  --entry-point=io.quarkus.funqy.gcp.functions.FunqyBackgroundFunction \
  --runtime=java11 --trigger-resource hello_topic --trigger-event google.pubsub.topic.publish \
  --source=target/deployment

The entry point always needs to be io.quarkus.funqy.gcp.functions.FunqyBackgroundFunction as it will be this class that will bootstrap Quarkus.

You can also use the new Java 17 runtime by using --runtime=java17 in the gcloud command line.

The --trigger-resource option defines the name of the PubSub topic, and the --trigger-event google.pubsub.topic.publish option define that this function will be triggered by all message publication inside the topic.

To trigger an event to this function, you can use the gcloud functions call command:

gcloud functions call quarkus-example-funky-pubsub --data '{"data":"Pub/Sub"}'

The --data '{"data":"Hello, Pub/Sub"}' option allows you to specify the message to be sent to PubSub.

Background Functions - Cloud Storage

Before deploying your function, you need to create a bucket.

gsutil mb gs://quarkus-hello

Then, use this command to deploy to Google Cloud Functions:

gcloud functions deploy quarkus-example-funky-storage \
  --entry-point=io.quarkus.funqy.gcp.functions.FunqyBackgroundFunction \
  --runtime=java11 --trigger-resource quarkus-hello --trigger-event google.storage.object.finalize \
  --source=target/deployment

The entry point always needs to be io.quarkus.funqy.gcp.functions.FunqyBackgroundFunction as it will be this class that will bootstrap Quarkus.

You can also use the new Java 17 runtime by using --runtime=java17 in the gcloud command line.

The --trigger-resource option defines the name of the Cloud Storage bucket, and the --trigger-event google.storage.object.finalize option define that this function will be triggered by all new file inside this bucket.

To trigger an event to this function, you can use the gcloud functions call command:

gcloud functions call quarkus-example-funky-storage --data '{"name":"test.txt"}'

The --data '{"name":"test.txt"}' option allow to specify a fake file name, a fake Cloud Storage event will be created for this name.

You can also simply add a file to Cloud Storage using the command line of the web console.

Cloud Events Functions - Cloud Storage

Cloud Events Function is a feature of Cloud Functions gen 2 only.

Before deploying your function, you need to create a bucket.

gsutil mb gs://quarkus-hello

Then, use this command to deploy to Google Cloud Functions:

gcloud beta functions deploy quarkus-example-cloud-event --gen2 \
  --entry-point=io.quarkus.funqy.gcp.functions.FunqyCloudEventsFunction \
  --runtime=java11 --trigger-bucket=example-cloud-event --source=target/deployment

The entry point always needs to be io.quarkus.funqy.gcp.functions.FunqyCloudEventsFunction as it will be this class that will bootstrap Quarkus.

You can also use the new Java 17 runtime by using --runtime=java17 in the gcloud command line.

The --trigger-bucket= option defines the name of the Cloud Storage bucket.

To trigger the event, you can send a file to the GCS example-cloud-event bucket.

Testing locally

The easiest way to locally test your function is using the Cloud Function invoker JAR.

You can download it via Maven using the following command:

mvn dependency:copy \
    -Dartifact='com.google.cloud.functions.invoker:java-function-invoker:1.1.0' \
    -DoutputDirectory=.

Before using the invoker, you first need to build your function via:

CLI
quarkus build
Maven
./mvnw clean package
Gradle
./gradlew build

Then you can use it to launch your function locally, again, the command depends on the type of function and the type of events.

Background Functions - PubSub

For background functions, you launch the invoker with a target class of io.quarkus.funqy.gcp.functions.FunqyBackgroundFunction.

java -jar java-function-invoker-1.1.0.jar \
  --classpath target/funqy-google-cloud-functions-1.0.0-SNAPSHOT-runner.jar \
  --target io.quarkus.funqy.gcp.functions.FunqyBackgroundFunction
The --classpath parameter needs to be set to the previously packaged JAR that contains your function class and all Quarkus related classes.

Then you can call your background function via an HTTP call with a payload containing the event:

curl localhost:8080 -d '{"data":{"data":"world"}}'

This will call your PubSub background function with a PubSubMessage {"data":"hello"}.

Background Functions - Cloud Storage

For background functions, you launch the invoker with a target class of io.quarkus.funqy.gcp.functions.FunqyBackgroundFunction.

java -jar java-function-invoker-1.1.0.jar \
  --classpath target/funqy-google-cloud-functions-1.0.0-SNAPSHOT-runner.jar \
  --target io.quarkus.funqy.gcp.functions.FunqyBackgroundFunction
The --classpath parameter needs to be set to the previously packaged JAR that contains your function class and all Quarkus related classes.

Then you can call your background function via an HTTP call with a payload containing the event:

curl localhost:8080 -d '{"data":{"name":"text"}}'

This will call your PubSub background function with a Cloud Storage event {"name":"file.txt"}, so an event on the file.txt file.

Cloud Events Functions - Cloud Storage

Cloud Events Function is a feature of Cloud Functions gen 2 only.

For cloud events functions, you launch the invoker with a target class of io.quarkus.funqy.gcp.functions.FunqyCloudEventsFunction`.

java -jar java-function-invoker-1.1.0.jar \
  --classpath target/funqy-google-cloud-functions-1.0.0-SNAPSHOT-runner.jar \
  --target io.quarkus.funqy.gcp.functions.FunqyBackgroundFunction
The --classpath parameter needs to be set to the previously packaged JAR that contains your function class and all Quarkus related classes.

Then you can call your background function via an HTTP call with a payload containing the event:

curl localhost:8080 \
  -X POST \
  -H "Content-Type: application/json" \
  -H "ce-id: 123451234512345" \
  -H "ce-specversion: 1.0" \
  -H "ce-time: 2020-01-02T12:34:56.789Z" \
  -H "ce-type: google.cloud.storage.object.v1.finalized" \
  -H "ce-source: //storage.googleapis.com/projects/_/buckets/MY-BUCKET-NAME" \
  -H "ce-subject: objects/MY_FILE.txt" \
  -d '{
        "bucket": "MY_BUCKET",
        "contentType": "text/plain",
        "kind": "storage#object",
        "md5Hash": "...",
        "metageneration": "1",
        "name": "MY_FILE.txt",
        "size": "352",
        "storageClass": "MULTI_REGIONAL",
        "timeCreated": "2020-04-23T07:38:57.230Z",
        "timeStorageClassUpdated": "2020-04-23T07:38:57.230Z",
        "updated": "2020-04-23T07:38:57.230Z"
      }'

This will call your cloud events function with an event on the "MY_FILE.txt file.

What’s next?

If you are looking for JAX-RS, Servlet or Vert.x support for Google Cloud Functions, we have it thanks to our Google Cloud Functions HTTP binding.