Template: openfaas-quarkus-native-template

The Quarkus template uses maven as a build system.

The template makes use of the OpenFAAS incubator project of-watchdog.

Quarkus is a Kubernetes Native Java stack tailored for GraalVM & OpenJDK HotSpot, crafted from the best of breed Java libraries and standards. The very nature of the project makes it a perfect fit for serverless too. This template is a barebores quarkus template you would generate from:

mvn io.quarkus:quarkus-maven-plugin:0.12.0:create \
    -DprojectGroupId=org.acme \
    -DprojectArtifactId=function \
    -DclassName="org.acme.quickstart.GreetingResource" \
    -Dpath="/"

Packaged as a template to quickly be deployed on OpenFAAS. This means that all the official features and extensions can be used out of the box in your functions too.

Structure

This a template showcasing the use of Native Quarkus as a viable runtime for Serverless functions.

Functions are pure JAX-RS routes:

@Path("/function")
public class GreetingResource {

    @GET
    @Produces(MediaType.TEXT_PLAIN)
    public String hello() {
        return "hello OpenFaaS";
    }
}

This template is not different than a regular Qaurkus application, all features you could use with Quarkus can be used here too.

To get started with Qaurkus, please read the official Getting Started Guide.

Using extensions

Quarkus has several extensions available. They can be used with this template using the standard mechanisms:

# See the available extensions
$ mvn quarkus:list-extensions
# Add a specific extension
$ mvn quarkus:add-extension -Dextensions="groupId:artifactId"

To conclude, using Quarkus for serverless is exactly the same as using quarkus for regular applications.

Trying the template

$ faas template pull https://github.com/pmlopes/openfaas-quarkus-native-template
$ faas new --lang quarkus-native <fn-name>

Building

When working in development mode, the java application is build as usual:

mvn clean package quarkus:dev

When going to OpenFAAS, the build is run inside a Docker container using the provided Dockerfile.

The Dockerfile performs the following actions:

1. Builds the Java code
2. Generates a native image from the fat jar
3. Creates a new image and install OpenFAAS of-watchdog
4. Copies the native image to the new container
5. Configures the watchdog

You can also run the Dockerfile locally:

docker build -t my-quarkus-fn .
docker run --rm -p 8080:8080 my-quarkus-fn

You can observe instant startup times and low memory usage:

Forking - function []
2019/03/27 12:01:45 Started logging stderr from function.
2019/03/27 12:01:45 Started logging stdout from function.
2019/03/27 12:01:45 OperationalMode: http
2019/03/27 12:01:45 Writing lock-file to: /tmp/.lock
2019/03/27 12:01:45 stdout: 2019-03-27 12:01:45,759 INFO  [io.quarkus] (main) Quarkus 0.12.0 started in 0.003s. Listening on: http://0.0.0.0:8000

2019/03/27 12:01:45 stdout: 2019-03-27 12:01:45,759 INFO  [io.quarkus] (main) Installed features: [cdi, resteasy]

docker stats
CONTAINER ID        NAME                CPU %               MEM USAGE / LIMIT     MEM %               NET I/O             BLOCK I/O           PIDS
90b8a84d23a9        suspicious_ganguly   0.00%               5.594MiB / 15.54GiB   0.04%               0B / 0B             0B / 0B             20

Remember that the memory usage in this case accounts for both the vert.x application and the watchdog!