Overview

Apache OpenWhisk is a popular container-native serverless platform. This chart targets to deploy an OpenWhisk cluster over Kubernetes cluster.

This chart is designed to deploy the following 6 kinds of containers on a running Kubernetes cluster:

• zookeeper: deployed in Kubernetes as a Service(backended by a Deployment). Provides zookeeper service for kafka node.
• kafka: deployed in Kubernetes as a StatefulSet. Depends on zookeeper service and provides message service for controller node and invoker node.
• couchdb: deployed in Kubernetes as a Service(backended by a Deployment). Provides database service for controller node and invoker node.
• controller: OpenWhisk controller component, deployed as a StatefulSet.
• invoker: OpenWhisk invoker component, deployed as a StatefulSet.
• nginx: deployed in Kubernetes as a combination of a Service(of type NodePort, backended by a Deployment), a ConfigMap and a Secret. Provides public access endpoint for end user to visit OpenWhisk.

By default, deploying this chart will result in deploying 6 containers in a Kubernetes cluster, which forms a minimum deployment of a workable OpenWhisk environment. Please modify values.yaml and corresponding template files to deploy a bigger customized OpenWhisk cluster.

Deployment Steps

Please follow the following steps in this section to use Helm to deploy this chart.

Step 1. Prepare Docker Images

The first step is to prepare docker images used by this chart on your Kubernetes node. Here is a summary of the images needed:

• zookeeper: uses zookeeper:3.4 at present.
• kafka: uses wurstmeister/kafka:0.11.0.1.
• couchdb: uses openwhisk/kube-couchdb, this is a pre-built docker image made from official openwhisk-on-kubernetes. For more information, please check the docker file for this image.
• controller: uses OpenWhisk official openwhisk/controller image.
• invoker: uses OpenWhisk official openwhisk/invoker image.
• nginx: uses nginx:1.11.

This chart provides default images for all of the above containers, so you can try deploy without building any images in advance.

This chart will also automatically pull the following action images for invoker once deployment is finished:

• openwhisk/nodejsactionbase
• openwhisk/nodejs6action
• openwhisk/dockerskeleton
• openwhisk/python2action
• openwhisk/python3action
• openwhisk/action-swift-v3.1.1
• openwhisk/swift3action
• openwhisk/java8action

Step 2. Prepare Kubernetes and Helm

Make sure that you have a running Kubernetes cluster and a kubectl client connected to this cluster.

Then please install Helm and run the following command to init Helm Tiller:

helm init

Please check with the following command to make sure Helm is up and running:

kubectl get pods -n kube-system

Then grant corresponding cluster role to Helm user:

kubectl create clusterrolebinding tiller-cluster-admin --clusterrole=cluster-admin --serviceaccount=kube-system:default

Finally, create a new namespace named openwhisk:

kubectl create namespace openwhisk

Now, you should have an available environment to deploy OpenWhisk!

Deploy Charts

Deployment can be done by using the following single command:

helm install . --namespace=openwhisk --name=your_release_name

After a while, if you can see all the pods listed by the following command are in Running state, congratulations, you have finished OpenWhisk deployment:

kubectl get pods -n openwhisk

Test Deployment

Install an OpenWhisk client to test the deployed OpenWhisk environment.

For now, we are using nginx to provide web access for OpenWhisk client. By default, the nginx service is configured to run at port 30000 for HTTP connection and 30001 for HTTPS connection.

As a result, please run the following command to config your OpenWhisk client:

wsk property set --apihost http://<nginx_node_IP>:30000
wsk property set --auth 23bc46b1-71f6-4ed5-8c54-816aa4f8c502:123zO3xZCLrMN6v2BKK1dXYFpXlPkccOFqm12CdAsMgRU4VrNZ9lyGVCGuMDGIwP

Prepare a small js function like the following and save it to greeting.js:

/**
 * Return a simple greeting message for someone.
 *
 * @param name A person's name.
 * @param place Where the person is from.
 */
function main(params) {
    var name = params.name || params.payload || 'stranger';
    var place = params.place || 'somewhere';
    return {payload:  'Hello, ' + name + ' from ' + place + '!'};
}

Create an OpenWhisk action by:

wsk action create hello ./greeting.js

And try this action:

wsk action invoke hello -b

If the action is invoked and message is returned without error, congratulations, you have a running OpenWhisk cluster on Kubernetes, enjoy it!

Cleanup

Use the following command to remove the deployment:

helm delete <release_name>

or with a --purge option if you want to completely remove the deployment from helm:

helm delete <release_name> --purge

References

Part of this chart is based on the project OpenWhisk Deployment for Kubernetes. This is a project using ansible to deploy OpenWhisk on Kubernetes. Please visit the project on github to get more details.