Photons

Setup

To try Photons you need to have an installation of OpenWhisk and setup the Java runtime environment. To do so

• checkout the devel branch of this repository and follow the instructions below on how to "Deploying the Java runtime image to OpenWhisk";
• unlock concurrent requests for the Java runtime environment java8 (see details in OpenWhisk docs).

Testing

There are multiple tests in the directory test-app. Tests include simple examples of functions which scripts to help registering the function and invoking it. Scripts might have paths to OpenWhisk installation that might need to be updated.

Apache OpenWhisk runtimes for java

Changelogs

• Java 8 CHANGELOG.md

Quick Java Action

A Java action is a Java program with a method called main that has the exact signature as follows:

public static com.google.gson.JsonObject main(com.google.gson.JsonObject);

For example, create a Java file called Hello.java with the following content:

import com.google.gson.JsonObject;

public class Hello {
    public static JsonObject main(JsonObject args) {
        String name = "stranger";
        if (args.has("name"))
            name = args.getAsJsonPrimitive("name").getAsString();
        JsonObject response = new JsonObject();
        response.addProperty("greeting", "Hello " + name + "!");
        return response;
    }
}

In order to compile, test and archive Java files, you must have a JDK 8 installed locally.

Then, compile Hello.java into a JAR file hello.jar as follows:

javac Hello.java

jar cvf hello.jar Hello.class

Note: google-gson must exist in your Java CLASSPATH when compiling the Java file.

You need to specify the name of the main class using --main. An eligible main class is one that implements a static main method as described above. If the class is not in the default package, use the Java fully-qualified class name, e.g., --main com.example.MyMain.

If needed you can also customize the method name of your Java action. This can be done by specifying the Java fully-qualified method name of your action, e.q., --main com.example.MyMain#methodName

Create the Java Action

To use as a docker action:

wsk action update helloJava hello.jar --main Hello --docker openwhisk/java8action

This works on any deployment of Apache OpenWhisk

To use on a deployment of OpenWhisk that contains the runtime as a kind:

wsk action update helloJava hello.jar --main Hello --kind java:8

Invoke the Java Action

Action invocation is the same for Java actions as it is for Swift and JavaScript actions:

wsk action invoke --result helloJava --param name World

  {
      "greeting": "Hello World!"
  }

Local development

Pre-requisites

• Gradle
• Docker Desktop (local builds)

Build and Push image to a local Docker registry

1. Start Docker Desktop (i.e., Docker daemon)

2. Build the Docker runtime image locally using Gradle:

./gradlew core:java8:distDocker

This will produce the image whisk/java8action and push it to the local Docker Desktop registry with the latest tag.

3. Verify the image was registered:

$ docker images whisk/*
REPOSITORY           TAG     IMAGE ID            CREATED             SIZE
whisk/java8action    latest  35f90453905a        7 minutes ago       521MB

Build and Push image to a remote Docker registry

Build the Docker runtime image locally using Gradle supplying the image Prefix and Registry domain (default port):

docker login
./gradlew core:java8:distDocker -PdockerImagePrefix=$prefix-user -PdockerRegistry=docker.io

Deploying the Java runtime image to OpenWhisk

Deploy OpenWhisk using ansible environment that contains the kind java:8 Assuming you have OpenWhisk already deployed locally and OPENWHISK_HOME pointing to root directory of OpenWhisk core repository.

Set ROOTDIR to the root directory of this repository.

Redeploy OpenWhisk

cd $OPENWHISK_HOME/ansible
ANSIBLE_CMD="ansible-playbook -i ${ROOTDIR}/ansible/environments/local"
$ANSIBLE_CMD setup.yml
$ANSIBLE_CMD couchdb.yml
$ANSIBLE_CMD initdb.yml
$ANSIBLE_CMD wipe.yml
$ANSIBLE_CMD openwhisk.yml

Or you can use wskdev and create a soft link to the target ansible environment, for example:

ln -s ${ROOTDIR}/ansible/environments/local ${OPENWHISK_HOME}/ansible/environments/local-java
wskdev fresh -t local-java

Testing

Install dependencies from the root directory on $OPENWHISK_HOME repository

pushd $OPENWHISK_HOME
./gradlew install
popd $OPENWHISK_HOME

Using gradle to run all tests

./gradlew :tests:test

Using gradle to run some tests

./gradlew :tests:test --tests *ActionContainerTests*

Using IntelliJ:

• Import project as gradle project.
• Make sure working directory is root of the project/repo

Using container image to test

To use as docker action push to your own dockerhub account

docker tag whisk/java8action $user_prefix/java8action
docker push $user_prefix/java8action

Then create the action using your the image from dockerhub

wsk action update helloJava hello.jar --main Hello --docker $user_prefix/java8action

The $user_prefix is usually your dockerhub user id.

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Troubleshooting

Gradle build fails with "Too many files open"

This may occur on MacOS as the default maximum # of file handles per session is 256. The gradle build requires many more and is unable to open more files (e.g., java.io.FileNotFoundException). For example, you may see something like:

> java.io.FileNotFoundException: /Users/XXX/.gradle/caches/4.6/scripts-remapped/build_4mpzm2wl8gipqoxzlms7n6ctq/7gdodk7z6t5iivcgfvflmhqsm/cp_projdf5583fde4f7f1f2f3f5ea117e2cdff1/cache.properties (Too many open files)

You can see this limit by issuing:

$ ulimit -a
open files                      (-n) 256

In order to increase the limit, open a new terminal session and issue the command (and verify):

$ ulimit -n 10000

$ ulimit -a
open files                      (-n) 10000

Gradle Task fails on :core:java8:tagImage

Docker daemon is not started and the Task is not able to push the image to your local registry.

License

Apache 2.0