Cross-namespace communication in Kubernetes - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to specify the namespace when accessing a service in another namespace.

Kubernetes

kubectl get svc my-service -n [1]

Drag options to blanks, or click blank then click option'

Adefault

Bproduction

Ckube-system

Ddev

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to specify the namespace, causing errors or looking in the wrong namespace.

Using -n production tells kubectl to look for the service in the 'production' namespace.

2fill in blank

medium

Complete the service URL to access a service named 'api' in the 'backend' namespace from another namespace.

Kubernetes

http://api.[1].svc.cluster.local

Drag options to blanks, or click blank then click option'

Abackend

Bfrontend

Cdefault

Dkube-system

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong namespace in the URL, causing DNS resolution failure.

The full DNS name includes the service name, namespace, and cluster domain. Here, the namespace is 'backend'.

3fill in blank

hard

Fix the error in the pod spec to allow cross-namespace service access by completing the service name with namespace.

Kubernetes

        - name: API_URL
          value: "http://api.[1].svc.cluster.local"

Drag options to blanks, or click blank then click option'

Adefault

Bfrontend

Cbackend

Dkube-system

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting the namespace or using the wrong namespace in the URL.

Specifying the correct namespace 'backend' in the service URL allows the pod to reach the service across namespaces.

4fill in blank

hard

Fill both blanks to create a NetworkPolicy that allows ingress traffic from pods in the 'frontend' namespace to pods in the 'backend' namespace.

Kubernetes

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: allow-frontend
  namespace: backend
spec:
  podSelector: {}
  ingress:
  - from:
    - namespaceSelector:
        matchLabels:
          [1]: [2]

Drag options to blanks, or click blank then click option'

Aname

Bfrontend

Capp

Dbackend

Attempts:

3 left

💡 Hint

Common Mistakes

Using pod labels instead of namespace labels, or wrong label keys/values.

The NetworkPolicy uses namespaceSelector with label name: frontend to allow traffic from the 'frontend' namespace.

5fill in blank

hard

Fill all three blanks to create a RoleBinding that grants the 'view' role to the 'dev-team' group in the 'testing' namespace.

Kubernetes

apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: view-binding
  namespace: [1]
subjects:
- kind: Group
  name: [2]
  apiGroup: rbac.authorization.k8s.io
roleRef:
  kind: Role
  name: [3]
  apiGroup: rbac.authorization.k8s.io

Drag options to blanks, or click blank then click option'

Atesting

Bdev-team

Cview

Dadmin

Attempts:

3 left

💡 Hint

Common Mistakes

Using cluster roles instead of roles, or wrong namespace or group names.

This RoleBinding applies in the 'testing' namespace, grants the 'view' role to the 'dev-team' group.