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# Deploying OpenWhisk on Kubernetes in Docker for Mac

## Overview

If you are using a Mac 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 laptop without needing
any additional virtualization software installed.

## Initial setup

### Creating the Kubernetes Cluster

Step-by-step instructions on enabling Kubernetes in Docker are
available as part of the
[Getting started](https://docs.docker.com/docker-for-mac/#Kubernetes)
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. It is recommended that you use the
`kubectl` cli that is installed by Docker in `/usr/local/bin`, so
please make sure it is appears in your path before any `kubectl` you
might also have installed on your machine.  Finally, pick the
`docker-desktop` config for `kubectl` by executing the command
`kubectl config use-context docker-desktop`.

### Configuring OpenWhisk

You will be using a NodePort ingress to access OpenWhisk. Assuming
port 31001 is available to be used on your host machine, a
[mycluster.yaml](../deploy/docker-macOS/mycluster.yaml]
for a standard deployment of OpenWhisk would be:
```yaml
whisk:
  ingress:
    type: NodePort
    apiHostName: localhost
    apiHostPort: 31001
    useInternally: false

nginx:
  httpsNodePort: 31001

# A single node cluster; so disable affinity
affinity:
  enabled: false
toleration:
  enabled: false
invoker:
  options: "-Dwhisk.kubernetes.user-pod-node-affinity.enabled=false"
```

## 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.
```yaml
controller:
  imageName: "whisk/controller"
  imageTag: "latest"
```

## Limitations

Using Kubernetes in Docker for Mac 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.