kubeteach

Kubeteach is an operator build with kubebuilder to learn kubernetes in kubernetes.

Kubeteach was created because I wanted to improve my golang and kubernetes operator knowledge. I came across kubebuilder and had the idea to learn kubernetes in kubernetes.

The idea is to get tasks as a kubernetes objects (custom resource) to learn how to interact with kubernetes/kubectl while solving tasks in the kubernetes cluster. Kubeteach checks whether a task has been completed successfully based on defined conditions.

⚠️ Note: kubeteach is not designed to deploy it to a production cluster. I recommend to use kind to use kubeteach and learn kubernetes. There is no deletion job for created objects from exercises.

🚧 Kubeteach is still in a very early stage of development, which means it may not always be stable and major api changes are necessary.

⚠️ Unfortunately, only a few tasks are currently available. More tasks will be added soon.

To install kubeteach you need a kubernetes cluster. I recommend kind as a local environment, checkout the kind quick start.

You need also kubectl to interact with your cluster and helm to install kubeteach to your cluster.

• Checkout the installation kubectl guide.
• Checkout the installation helm guide.

To be able to deploy kubeteach you need to add the kubeteach helm repo to your local helm installation.

helm repo add kubeteach https://dergeberl.github.io/kubeteach-charts

To deploy kubeteach with an ExerciseSet you can select one of this list.

With the following command you can install kubeteach with an ExerciseSet to your cluster. (Change <helm-chart to your selected helm chart. For example kubeteach/kubeteach-exerciseset1)

helm install exerciseset1 <helm-chart> --namespace exerciseset --create-namespace --render-subchart-notes

⚠️ Don't use the helm flag --wait, because some deployments won't get ready and the helm install command will fail.

⚠️ The dashboard is an experimental feature. DO NOT MAKE IT AVAILABLE VIA INTERNET! ⚠️

To enable the dashboard you need to add 2 settings for the helm install command (see above):

--set kubeteach.dashboard.enabled=true --set kubeteach.webterminal.enabled=true

Example:

helm install exerciseset1 <helm-chart> --namespace exerciseset --set kubeteach.dashboard.enabled=true --set kubeteach.webterminal.enabled=true --render-subchart-notes
...
You can use it with the following command (to forward a local port):
kubectl port-forward -n exerciseset service/kubeteach-core-dashboard 8080:80

Now you can access the dashboard via http://localhost:8080
Username: kubeteach
Password: <yourpassword>

The command will prompt a command (kubectl port-forward) and the credentials which are needed to log in into the dashboard.

To update kubeteach you can run the following commands.

helm repo update
helm upgrade exerciseset1 <helm-chart> --namespace exerciseset --render-subchart-notes

⚠️ Don't use the helm flag --wait, because some deployments won't get ready and the helm install command will fail.

You can get the tasks that should be performed with kubectl get tasks -n exerciseset

kubectl get tasks
NAME    TITLE                           DESCRIPTION                                                                                                          STATUS
task01   Create namespace                Create a new namespace with the name kubeteach                                                                           active
task02   Create pod                      Create a pod in namespace kubeteach, name it pod1 and use nginx:latest as image                                         pending
...

To get more information of one task you can use kubectl describe task -n exerciseset <taskname>

In some task you can find a helpURL and/or a longDescription with more information about this task.

kubectl describe task task01   
Name:         task01
Namespace:    default
Labels:       <none>
Annotations:  <none>
API Version:  kubeteach.geberl.io/v1alpha1
Kind:         Task
Metadata:
  Creation Timestamp:  2021-03-14T18:35:49Z
  Generation:          1
  Owner References:
    API Version:     kubeteach.geberl.io/v1alpha1
    Kind:            TaskDefinition
    Name:            task1
    UID:             21b8853d-11d4-4930-bdfd-ea3c945ae536
  Resource Version:  633
  UID:               d392614d-6a42-4d97-8500-ee29f3121674
Spec:
  Description:  Create a new namespace with the name kubeteach
  Title:        Create namespace
Status:
  State:  active
Events:
  Type    Reason  Age   From  Message
  ----    ------  ----  ----  -------
  Normal  Active  12m   Task  Task has no pre required task, task is now active

Now you can solve tasks by doing what's described in the task.

For example task01: Create a new namespace with the name kubeteach

kubectl create namespace kubeteach

A few seconds later the task state is changed to successful.

kubectl get task task01            
NAME    TITLE              DESCRIPTION                                  STATUS
task01   Create namespace   Create a Namespace with the name kubeteach   successful

The task state pending shows that another task must be successfully done before.

If you need help you can take a look into the solution folder of the exercise set you use (for example dergeberl/kubeteach-charts/solutions/exerciseset1)

An update to a new status can take up to 5 seconds

Check out the docs/write-own-exercises.md

For more information about contribution and local test setup have a look at the contribution guideline.

New exercises or/and exercise sets are highly welcome, check out the helm repository.

If you have ideas feel free to open a PR or issue.