The OpenWhisk adapter is in the form of an executable jar that can be used in a a docker image to be deployed to Openwhisk. The platform works in request-response mode, listening on port 8080 on a specific endpoint, so the adapter is a simple Spring MVC application.

Quick Start

Implement a POF (be sure to use the functions package):

package functions;

import java.util.function.Function;

public class Uppercase implements Function<String, String> {

	public String apply(String input) {
		return input.toUpperCase();

Install it into your local Maven repository:

./mvnw clean install

Create a function.properties file that provides its Maven coordinates. For example:

dependencies.function: com.example:pof:0.0.1-SNAPSHOT

Copy the openwhisk runner JAR to the working directory (same directory as the properties file):

cp spring-cloud-function-adapters/spring-cloud-function-adapter-openwhisk/target/spring-cloud-function-adapter-openwhisk-2.0.0.BUILD-SNAPSHOT.jar runner.jar

Generate a m2 repo from the --thin.dryrun of the runner JAR with the above properties file:

java -jar -Dthin.root=m2 runner.jar --thin.name=function --thin.dryrun

Use the following Dockerfile:

FROM openjdk:8-jdk-alpine
COPY m2 /m2
ADD runner.jar .
ADD function.properties .
ENTRYPOINT [ "java", "-Djava.security.egd=file:/dev/./urandom", "-jar", "runner.jar", "--thin.root=/m2", "--thin.name=function", "--function.name=uppercase"]
you could use a Spring Cloud Function app, instead of just a jar with a POF in it, in which case you would have to change the way the app runs in the container so that it picks up the main class as a source file. For example, you could change the ENTRYPOINT above and add --spring.main.sources=com.example.SampleApplication.

Build the Docker image:

docker build -t [username/appname] .

Push the Docker image:

docker push [username/appname]

Use the OpenWhisk CLI (e.g. after vagrant ssh) to create the action:

wsk action create example --docker [username/appname]

Invoke the action:

wsk action invoke example --result --param payload foo
    "result": "FOO"