Kubernetes Playgrounds

NOTE: This is a beta product being actively developed.

Kubernetes playgrounds are full K8s sandboxes to experiment with; there are no problems to solve. There will be a separate section for K8s troubleshooting scenarios.

You can use these playgrounds for whatever you want. Each playground includes manifests for specific tools; you can apply them (e.g., kubectl apply -f nginx.yaml) or write your own K8s manifests.

Usage

Click “Start Playground” on your desired playground. After a few seconds, you will be redirected to the playground page.

On this page, click “Open the Server Terminal in a new Window”. This opens a “Hold on, we’re starting your session…” window. If there are no issues, you should get the terminal prompt in about 60 seconds. You can try refreshing the window before the timer is up.

Please note that if the underlying K8s infrastructure does not have capacity to create your new playground, it will spin up a new node, adding about two minutes to the process, for a total of about three minutes.

At any time you can terminate the playground (please do when you are done).

The playground will be destroyed when it reaches its maximum time.

Please also note that free accounts are limited in the number of playgrounds they can run at a given time. Paid plans (Pro and Business) do not have such restrictions.

Tips

You can use k as a shorthand for kubectl.

Autocomplete is enabled. For example, you can type k g, press TAB, and it will autocomplete to k get. If there are multiple options, they will be displayed (e.g., typing k de and pressing TAB shows “debug”, “delete”, and “describe”, with a brief summary of each).

There’s no need in general to change contexts or namespaces, as in by default you are in the right one.

Known Issues

• Sometimes the web terminal gets disconnected and shows a “Connection Closed” message (the same as when the playground is terminated manually or because it ran out of time). Refreshing this window restores the command prompt.

• If you go to the URL of a session that doesn’t exist, you’ll get the “Hold on, we’re starting your session…” window, which is an incorrect message in this case.

Kubernetes Restrictions

• Computing resources (CPU, memory, and disk) are limited (Pro accounts have fewer limitations).
• Kubernetes primitives (like the number of pods) are limited (Pro accounts have fewer limitations).
• Playgrounds for free accounts don’t have access to the Internet. As a result, there’s only a limited number of Docker images available from the internal repository.
• There is no direct access to the Kubernetes control plane.

Tooling

There are a number of Kubernetes tools installed in the session container (where you run commands), such as k9s.

The official krew extensions are installed (type kubectl- and press TAB):

kubectl-ctx          kubectl-ns           kubectl-tree         
kubectl-images       kubectl-stern        kubectl-view_secret  
kubectl-krew         kubectl-tail         kubectl-who_can

You can run them with the hyphen or with a space (e.g., k ns).

Editors: vi (vim) and nano are available.

Is there a tool you want that is not installed? Contact us and let us know.

Docker images

There’s an internal Docker registry you can access for amd64 images (the K8s nodes’ architecture): registry.sadsre.com/amd64/.

Current images that you can declare in your manifests are:

• nginx: registry.sadsre.com/amd64/nginx with tags :latest :1.29 :1.29.0

(More images will be added. Please let us know if you want a particular one).