Kubernetes : Docker Desktop

How to install OpenSquiggly on Docker Desktop Kubernetes.

Overview of Installing on Docker Desktop

The Kubernetes distribution that comes as part of Docker Desktop is, similar to Minikube, a lightweight, desktop installable Kubernetes manager and an excellent option for evaluating OpenSquiggly.

Install Prerequisites

  • Install Docker Desktop
  • Install the kubectl and helm tools using the instructions here.
  • Add the OpenSquiggly Helm chart repository to your list of Helm repositories:
helm repo add opensquiggly https://opensquiggly.github.io/helm-charts

Enable Kubernetes

Kubernetes comes as part of the Docker Desktop installation, but is not enabled by default.

To enable Docker Desktop Kubernetes, open your Docker Desktop preferences, navigate to the Kubernetes section, and click the “Enable Kubernetes” checkbox.

Doing so will add “docker-desktop” to your Kubernetes context list.

To verify that Docker Desktop Kubernetes is available, open a terminal and issue the command:

kubectl config get-contexts

Confirm that “docker-desktop” appears in the list and is set as your current context.

Install OpenSquiggly Using the Helm Chart

Install OpenSquiggly using the command:

helm install release-name-here opensquiggly/allinone --set cloudType=docker-desktop[,diskSize=xx]

where xx is the desired disk size in gigabytes. If omitted, the default disk size is 32Gb.


helm install opensquiggly1 opensquiggly/allinone --set cloudType=docker-desktop,diskSize=40

Docker Desktop works a little different in exposing LoadBalancer services than does Minikube.

Get a list of your current Kubernetes services with the command:

kubectl get svc

Sample Output

NAME                TYPE           CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
kubernetes          ClusterIP        <none>        443/TCP        185d
opensquiggly1-svc   LoadBalancer     localhost     80:30893/TCP   13m
               Load balancer is exposed to localhost ---+

Notice that the LoadBalancer has been assigned localhost as the external-ip address. For comparison, Minikube, doesn’t do this … it leaves the external-ip address as pending.

Since the OpenSquiggly LoadBalancer service is published to localhost, that means we can simply navigate the browser to localhost (without any other port numbers) and we should get to the OpenSquiggly login page.


Limitations and Workarounds

While it is convenient that Docker Desktop exposes the external-ip address of the service to localhost, there’s an obvious problem. What happens if you install two services that both need LoadBalancers, and therefore both want access to localhost as their external-ip address?

Docker Desktop will only expose one LoadBalancer to localhost. Any other LoadBalancers will remain in the pending state for their external-ip address. This means you can only have one service at a time accessible to your browser.

To get around this, you can use Kubernete’s port forwarding feature.

kubectl port-forward svc/service-name port_number:80

For example, in the above example we could expose the opensquiggl1-svc to port 4000 with the command:

kubectl port-forward svc/opensquiggly1-svc 4000:80

Note that the external port number we choose (4000 in this case), does not need to match the internal port number (30893 in this case).

We can now access OpenSquiggly by navigating the browser to: