Deploying OpenWhisk on Kubernetes in Docker for Windows

Overview

If you are using Windows as your development machine, the simplest way to get a Kubernetes cluster for local development is to use the built-in support for running a single node Kubernetes cluster that is available in Docker 18.06 and later. This will let you use Helm to deploy Apache OpenWhisk to Kubernetes on your computer without needing to install Minikube or otherwise run inside a virtual machine.

Quick-start

Chocolatey

You can use the Chocolatey package manager to quickly set up your Docker cluster on Windows.

  • Install Chocolatey
  • Install Docker Desktop: choco install docker-desktop
  • Install helm: choco install kubernetes-helm

Initial setup

Creating the Kubernetes Cluster

Step-by-step instructions on enabling Kubernetes in Docker are available as part of the Getting started documentation from Docker.

In a nutshell, open the Docker preferences window, switch to the Advanced panel and make sure you have at least 4GB of Memory allocated to Docker. Then switch to the Kubernetes panel, and check the box to enable Kubernetes.

Using Git to Clone this Repository

git clone https://github.com/apache/openwhisk-deploy-kube.git

Configuring OpenWhisk

You will be using a NodePort ingress to access OpenWhisk. Assuming kubectl describe nodes | grep InternalIP returns 192.168.65.3 and port 31001 is available to be used on your host machine, a mycluster.yaml for a standard deployment of OpenWhisk would be:

whisk:
  ingress:
    type: NodePort
    apiHostName: 192.168.65.3
    apiHostPort: 31001

nginx:
  httpsNodePort: 31001

Using helm to install OpenWhisk

Execute these two commands and wait a few seconds for the tiller-deploy pod in the kube-system namespace to be in the Running state:

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

Indicate the Kubernetes worker nodes that should be used to execute user containers by OpenWhisk's invokers. For a single node development cluster, simply run:

kubectl label nodes --all openwhisk-role=invoker

Now you're ready to run helm to set up OpenWhisk. Make sure you created your mycluster.yaml file as described above, and run:

cd openwhisk-deploy-kube
helm install ./helm/openwhisk --namespace=openwhisk --name=owdev -f mycluster.yaml

You can use the command helm status owdev to get a summary of the various Kubernetes artifacts that make up your OpenWhisk deployment. Once the install-packages Pod is in the Completed state, your OpenWhisk deployment is ready to be used.

Tip: If you notice errors or pods stuck in the pending state (init-couchdb as an example), try running kubectl get pvc --all-namespaces. If you notice that claims are stuck in the Pending state, you may need to follow the workaround mentioned in this Docker for Windows Github Issue.

You are now ready to set up the wsk cli. Further instructions can be found here. Follow the Docker for Windows instructions.

Hints and Tips

One nice feature of using Kubernetes in Docker, is that the containers being run in Kubernetes are also directly visible/accessible via the usual Docker commands. Furthermore, it is straightforward to deploy local images by adding a stanza to your mycluster.yaml. For example, to use a locally built controller image, just add the stanza below to your mycluster.yaml to override the default behavior of pulling a stable openwhisk/controller image from Docker Hub.

controller:
  imageName: "whisk/controller"
  imageTag: "latest"

Limitations

Using Kubernetes in Docker for Windows is only appropriate for development and testing purposes. It is not recommended for production deployments of OpenWhisk.

TLS termination will be handled by OpenWhisk's nginx service and will use self-signed certificates. You will need to invoke wsk with the -i command line argument to bypass certificate checking.

The docker network is not exposed to the host on Windows. However, the exposed ports for NodePort services are forwarded from localhost. Therefore you must use different host names to connect to OpenWhisk from outside the cluster (with the wsk cli) and from inside the cluster (in mycluster.yaml). Continuing the example from above, when setting the --apihost for the wsk cli, you would use localhost:31001.