OpenWhisk Deployment on Kubernetes

Apache OpenWhisk is an open source, distributed Serverless platform that executes functions (fx) in response to events at any scale. The OpenWhisk platform supports a programming model in which developers write functional logic (called Actions), in any supported programming language, that can be dynamically scheduled and run in response to associated events (via Triggers) from external sources (Feeds) or from HTTP requests.

This repository supports deploying OpenWhisk to Kubernetes. It contains a Helm chart that can be used to deploy the core OpenWhisk platform and optionally some of its Event Providers to both single-node and multi-node Kubernetes clusters.

The same Helm chart can also be used to deploy OpenWhisk to OKD/OpenShift via a strategy of using helm template to generate yaml that is then fed to the oc cli. There are some rough edges still in this process, we would welcome community contributions to help improve the targeting of OKD/OpenShift and document the necessary steps.

Table of Contents

• Prerequisites: Kubernetes and Helm
• Deploying OpenWhisk
• Administering OpenWhisk
• Development and Testing OpenWhisk on Kubernetes
• Cleanup
• Issues

Prerequisites: Kubernetes and Helm

Kubernetes is a container orchestration platform that automates the deployment, scaling, and management of containerized applications. Helm is a package manager for Kubernetes that simplifies the management of Kubernetes applications. You do not need to have detailed knowledge of either Kubernetes or Helm to use this project, but you may find it useful to review their basic documentation to become familiar with their key concepts and terminology.

Kubernetes

Your first step is to create a Kubernetes cluster that is capable of supporting an OpenWhisk deployment. Although there are some technical requirements that the Kubernetes cluster must satisfy, any of the options described below is acceptable.

Simple Docker-based options

The simplest way to get a small Kubernetes cluster suitable for development and testing is to use one of the Docker-in-Docker approaches for running Kubernetes directly on top of Docker on your development machine. Configuring Docker with 4GB of memory and 2 virtual CPUs is sufficient for the default settings of OpenWhisk. Depending on your host operating system, we recommend the following:

1. MacOS: Use the built-in Kubernetes support in Docker for Mac version 18.06 or later. Please follow our setup instructions to initially create your cluster.
2. Linux: Use kind. Please follow our setup instructions to initially create your cluster.
3. Windows: Use the built-in Kubernetes support in Docker for Windows version 18.06 or later. Please follow our setup instructions to initially create your cluster.

Using a Kubernetes cluster from a cloud provider

You can also provision a Kubernetes cluster from a cloud provider, subject to the cluster meeting the technical requirements. You will need at least 1 worker node with 4GB of memory and 2 virtual CPUs to deploy the default configuration of OpenWhisk. You can deploy to significantly larger clusters by scaling up the replica count of the various components and labeling multiple nodes as invoker nodes. We have detailed documentation on using Kubernetes clusters from the following major cloud providers:

• IBM (IKS) and IBM (ICP)
• Google (GKE)
• Amazon (EKS)

We would welcome contributions of documentation for Azure (AKS) and any other public cloud providers.

Using OKD/OpenShift

You will need at least 1 worker node with 4GB of memory and 2 virtual CPUs to deploy the default configuration of OpenWhisk. You can deploy to significantly larger clusters by scaling up the replica count of the various components and labeling multiple nodes as invoker nodes. For more detailed documentation, see:

• OKD/OpenShift 3.11

Using a Kubernetes cluster you built yourself

If you are comfortable with building your own Kubernetes clusters and deploying services with ingresses to them, you should also be able to deploy OpenWhisk to a do-it-yourself cluster. Make sure your cluster meets the technical requirements. You will need at least 1 worker node with 4GB of memory and 2 virtual CPUs to deploy the default configuration of OpenWhisk. You can deploy to significantly larger clusters by scaling up the replica count of the various components and labeling multiple nodes as invoker nodes.

Additional more detailed instructions:

• Some general comments.
• Using kubeadm on Ubuntu 18.04.

Helm

Helm is a tool to simplify the deployment and management of applications on Kubernetes clusters. The OpenWhisk Helm chart requires the Helm 3.

Our automated testing currently uses Helm v3.2.4

Follow the Helm install instructions for your platform to install Helm v3.0.1 or newer.

Deploying OpenWhisk

Now that you have your Kubernetes cluster and have installed the Helm 3 CLI, you are ready to deploy OpenWhisk.

Overview

You will use Helm to deploy OpenWhisk to your Kubernetes cluster. There are four deployment steps that are described in more detail below in the rest of this section.

1. Initial cluster setup. You will label your Kubernetes worker nodes to indicate their intended usage by OpenWhisk.
2. Customize the deployment. You will create a mycluster.yaml that specifies key facts about your Kubernetes cluster and the OpenWhisk configuration you wish to deploy.
3. Deploy OpenWhisk with Helm. You will use Helm and mycluster.yaml to deploy OpenWhisk to your Kubernetes cluster.
4. Configure the wsk CLI. You need to tell the wsk CLI how to connect to your OpenWhisk deployment.

Initial setup

Indicate the Kubernetes worker nodes that should be used to execute user containers by OpenWhisk's invokers. Do this by labeling each node with openwhisk-role=invoker. In the default configuration, which uses the KubernetesContainerFactory, the node labels are used in conjunction with Pod affinities to inform the Kubernetes scheduler how to place work so that user actions will not interfere with the OpenWhisk control plane. When using the non-default DockerContainerFactory, OpenWhisk assumes it has exclusive use of these invoker nodes and will schedule work on them directly, completely bypassing the Kubernetes scheduler. For a single node cluster, simply do

kubectl label nodes --all openwhisk-role=invoker

If you have a multi-node cluster, then for each node <INVOKER_NODE_NAME> you want to be an invoker, execute

$ kubectl label nodes <INVOKER_NODE_NAME> openwhisk-role=invoker

If you are targeting OKD/OpenShift, use the command

oc label node <INVOKER_NODE_NAME> openwhisk-role=invoker

For more precise control of the placement of the rest of OpenWhisk's pods on a multi-node cluster, you can optionally label additional non-invoker worker nodes. Use the label openwhisk-role=core to indicate nodes which should run the OpenWhisk control plane (the controller, kafka, zookeeeper, and couchdb pods). If you have dedicated Ingress nodes, label them with openwhisk-role=edge. Finally, if you want to run the OpenWhisk Event Providers on specific nodes, label those nodes with openwhisk-role=provider.

Disabling affinity (not recommended)

If the Kubernetes cluster does not allow you to assign a label to a node, or you cannot use the affinity attribute, you can disable it. Please note that it is suitable for testing purposes only and may interfere with the OpenWhisk control plane.

You can disable affinity by editing the mycluster.yaml file:

affinity:
  enabled: false
invoker:
  options: "-Dwhisk.kubernetes.user-pod-node-affinity.enabled=false"

Customize the Deployment

You must create a mycluster.yaml file to record key aspects of your Kubernetes cluster that are needed to configure the deployment of OpenWhisk to your cluster. For details, see the documentation appropriate to your Kubernetes cluster:

• Docker for Mac
• Docker for Windows
• kind
• IBM Kubernetes Service (IKS)
• IBM Cloud Private (ICP)
• Google (GKE)
• Amazon (EKS)
• OKD/OpenShift

Beyond the Kubernetes cluster specific configuration information, the mycluster.yaml file is also used to customize your OpenWhisk deployment by enabling optional features and controlling the replication factor of the various microservices that make up the OpenWhisk implementation. See the configuration choices documentation for a discussion of the primary options.

Deploy With Helm

For simplicity, in this README, we have used owdev as the release name and openwhisk as the namespace into which the Chart's resources will be deployed. You can use a different name and/or namespace simply by changing the commands used below.

NOTE: Clone the repository https://github.com/apache/openwhisk-deploy-kube.git and use to Helm chart available under the helm/openwhisk folder.

Deployment can be done by using the following single command:

helm install owdev ./helm/openwhisk -n openwhisk --create-namespace -f mycluster.yaml

NOTE: The above command will only work for Helm v3.2.0 or higher versions. Verfiy your local Helm version with the command helm version.

Deploying to OKD/OpenShift uses the command sequence:

helm template owdev ./helm/openwhisk -n openwhisk -f mycluster.yaml > owdev.yaml
oc create -f owdev.yaml

The two step sequence is currently required because the oc command must be used to create the Route resource specified in the generated owdev.yaml. We recommend generating to a file to make it easier to undeploy OpenWhisk later by simply doing oc delete -f owdev.yaml

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

NOTE: You can check the status of the pod by running the following command kubectl get pods -n openwhisk --watch.

Configure the wsk CLI

Configure the OpenWhisk CLI, wsk, by setting the auth and apihost properties (if you don't already have the wsk cli, follow the instructions here to get it). Replace whisk.ingress.apiHostName and whisk.ingress.apiHostPort with the actual values from your mycluster.yaml.

wsk property set --apihost <whisk.ingress.apiHostName>:<whisk.ingress.apiHostPort>
wsk property set --auth 23bc46b1-71f6-4ed5-8c54-816aa4f8c502:123zO3xZCLrMN6v2BKK1dXYFpXlPkccOFqm12CdAsMgRU4VrNZ9lyGVCGuMDGIwP

Configuring the CLI for Kubernetes on Docker for Mac and Windows

The docker0 network interface does not exist in the Docker for Mac/Windows host environment. Instead, exposed NodePorts are forwarded from localhost to the appropriate containers. This means that you will use localhost instead of whisk.ingress.apiHostName when configuring the wsk cli and replace whisk.ingress.apiHostPort with the actual values from your mycluster.yaml.

wsk property set --apihost localhost:<whisk.ingress.apiHostPort>
wsk property set --auth 23bc46b1-71f6-4ed5-8c54-816aa4f8c502:123zO3xZCLrMN6v2BKK1dXYFpXlPkccOFqm12CdAsMgRU4VrNZ9lyGVCGuMDGIwP

Verify your OpenWhisk Deployment

Your OpenWhisk installation should now be usable. You can test it by following these instructions to define and invoke a sample OpenWhisk action in your favorite programming language.

You can also issue the command helm test owdev -n openwhisk to run the basic verification test suite included in the OpenWhisk Helm chart.

Note: if you installed self-signed certificates, which is the default for the OpenWhisk Helm chart, you will need to use wsk -i to suppress certificate checking. This works around cannot validate certificate errors from the wsk CLI.

If your deployment is not working, check our troubleshooting guide for ideas.

Scale-up your OpenWhisk Deployment

Using defaults, your deployment is configured to provide a bare-minimum working platform for testing and exploration. For your specialized workloads, you can scale-up your openwhisk deployment by defining your deployment configurations in your mycluster.yaml which overrides the defaults in helm/openwhisk/values.yaml. Some important parameters to consider (for other parameters, check helm/openwhisk/values.yaml and configurationChoices):

• actionsInvokesPerminute: limits the maximum number of invocations per minute.
• actionsInvokesPerminute: limits the maximum concurrent invocations.
• containerPool: total memory available per invoker instance. Invoker uses this memory to create containers for user-actions. The concurrency-limit (actions running in parallel) will depend upon the total memory configured for containerPool and memory allocated per action (default: 256mb per container).

For more information about increasing concurrency-limit, check scaling-up your deployment.

Administering OpenWhisk

Wskadmin is the tool to perform various administrative operations against an OpenWhisk deployment.

Since wskadmin requires credentials for direct access to the database (that is not normally accessible to the outside), it is deployed in a pod inside Kubernetes that is configured with the proper parameters. You can run wskadmin with kubectl. You need to use the <namespace> and the deployment <name> that you configured with --namespace and --name when deploying.

You can then invoke wskadmin with:

kubectl -n <namespace> -ti exec <name>-wskadmin -- wskadmin <parameters>

For example, is your deployment name is owdev and the namespace is openwhisk you can list users in the guest namespace with:

$ kubectl -n openwhisk  -ti exec owdev-wskadmin -- wskadmin user list guest
23bc46b1-71f6-4ed5-8c54-816aa4f8c502:123zO3xZCLrMN6v2BKK1dXYFpXlPkccOFqm12CdAsMgRU4VrNZ9lyGVCGuMDGIwP

Check here for details about the available commands.

Development and Testing OpenWhisk on Kubernetes

This section outlines how common OpenWhisk development tasks are supported when OpenWhisk is deployed on Kubernetes using Helm.

Running OpenWhisk test cases

Some key differences in a Kubernetes-based deployment of OpenWhisk are that deploying the system does not generate a whisk.properties file and that the various internal microservices (invoker, controller, etc.) are not directly accessible from the outside of the Kubernetes cluster. Therefore, although you can run full system tests against a Kubernetes-based deployment by giving some extra command line arguments, any unit tests that assume direct access to one of the internal microservices will fail. First clone the core OpenWhisk repository locally and set $OPENWHISK_HOME to its top-level directory. Then, the system tests can be executed in a batch-style as shown below, where WHISK_SERVER and WHISK_AUTH are replaced by the values returned by wsk property get --apihost and wsk property get --auth respectively.

cd $OPENWHISK_HOME
./gradlew :tests:testSystemKCF -Dwhisk.auth=$WHISK_AUTH -Dwhisk.server=https://$WHISK_SERVER -Dopenwhisk.home=`pwd`

You can also launch the system tests as JUnit test from an IDE by adding the same system properties to the JVM command line used to launch the tests:

 -Dwhisk.auth=$WHISK_AUTH -Dwhisk.server=https://$WHISK_SERVER -Dopenwhisk.home=`pwd`

NOTE: You need to install JDK 8 in order to run these tests.

Deploying a locally built docker image.

If you are using Kubernetes in Docker, 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"

Selectively redeploying using a locally built docker image

You can use the helm upgrade command to selectively redeploy one or more OpenWhisk componenets. Continuing the example above, if you make additional changes to the controller source code and want to just redeploy it without redeploying the entire OpenWhisk system you can do the following:

# Execute these commands in your openwhisk directory
./gradlew distDocker
docker tag whisk/controller whisk/controller:v2

Then, edit your mycluster.yaml to contain:

controller:
  imageName: "whisk/controller"
  imageTag: "v2"

Redeploy with Helm by executing this commaned in your openwhisk-deploy-kube directory:

helm upgrade owdev ./helm/openwhisk -n openwhisk -f mycluster.yaml

Deploying Lean Openwhisk version.

To have a lean setup (no Kafka, Zookeeper and no Invokers as separate entities):

controller:
  lean: true

Cleanup

Use the following command to remove all the deployed OpenWhisk components:

helm uninstall owdev -n openwhisk

By default, helm uninstall removes the history of previous deployments. If you want to keep the history, add the command line flag --keep-history.

For OpenShift deployments, you cannot use helm uninstall to remove the OpenWhisk deployment because we did not do a helm install. If you saved the output from helm template into a file, you can simply use that file as an argument to oc delete. If you did not save the file, you can redo the helm template command and feed the generated yaml into an oc delete command.

Issues

If your OpenWhisk deployment is not working, check our troubleshooting guide for ideas.

Report bugs, ask questions and request features here on GitHub.

You can also join our slack channel and chat with developers. To get access to our slack channel, request an invite here.