Why operators extend Kubernetes - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a custom resource definition (CRD) in Kubernetes.

Kubernetes

kubectl apply -f [1]

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Adeployment.yaml

Bcrd.yaml

Cservice.yaml

Dpod.yaml

Attempts:

3 left

💡 Hint

Common Mistakes

Using a deployment.yaml file instead of a CRD file.

Applying a service.yaml which does not define custom resources.

The crd.yaml file defines a custom resource definition, which is essential for extending Kubernetes with operators.

2fill in blank

medium

Complete the command to check the status of custom resources managed by an operator.

Kubernetes

kubectl get [1]

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Amyresources

Bcustomresourcedefinitions

Cservices

Dpods

Attempts:

3 left

💡 Hint

Common Mistakes

Listing pods instead of custom resources.

Using 'customresourcedefinitions' which lists the definitions, not instances.

The operator manages custom resources, which have their own names like myresources. This command lists those resources.

3fill in blank

hard

Fix the error in the operator deployment YAML by completing the missing field.

Kubernetes

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-operator
spec:
  replicas: 1
  selector:
    matchLabels:
      name: my-operator
  template:
    metadata:
      labels:
        name: my-operator
    spec:
      containers:
      - name: operator
        image: my-operator-image:latest
        [1]: ["--enable-leader-election"]

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Acommand

Benv

Cargs

Dports

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'command' which overrides the container's default command.

Using 'env' which is for environment variables, not command arguments.

The args field passes arguments to the container command, such as enabling leader election in operators.

4fill in blank

hard

Fill both blanks to complete the reconciliation loop function signature in a Kubernetes operator.

Kubernetes

func (r *ReconcileMyResource) Reconcile(ctx context.Context, [1] ctrl.Request) ([2], error) {

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Areq

Bresult

Cctrl.Result

Derror

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'result' as the parameter name instead of 'req'.

Returning 'error' as the first return value instead of 'ctrl.Result'.

The Reconcile function takes a ctrl.Request named req and returns a ctrl.Result and an error.

5fill in blank

hard

Fill all three blanks to complete the operator's watch setup code.

Kubernetes

return ctrl.NewControllerManagedBy(mgr).
  For(&mygroupv1.MyResource{}).
  [1](&source.Kind{Type: &corev1.Pod{}}).
  [2](handler.EnqueueRequestForOwner(mgr.GetScheme(), [3])).
  Complete(r)

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AWatches

BIsController

DOwnerType

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'IsController' as the first method instead of 'Watches'.

Confusing 'OwnerType' with 'IsController' in the wrong place.

The operator watches Pods with Watches, filters with IsController, and sets the owner type with OwnerType.