Task Summary
Connect to host cka000056
Review existing frontend and backend Deployments
Choose one correct NetworkPolicy from the ~/netpol directory
The policy must:
Allow traffic only from the frontend Deployment to the backend Deployment
Avoid being overly permissive
Apply the correct NetworkPolicy without modifying any sample files
Step-by-Step Instructions
Step 1: SSH into the correct node
ssh cka000056
Step 2: Inspect the frontend Deployment
Check the labels used in the frontend Deployment:
kubectl get deployment -n frontend -o yaml
Look under metadata.labels or spec.template.metadata.labels. Note the app or similar label (e.g., app: frontend).
Step 3: Inspect the backend Deployment
kubectl get deployment -n backend -o yaml
Again, find the labels assigned to the pods (e.g., app: backend).
Step 4: List and review the provided NetworkPolicies
List the available files:
ls ~/netpol
Check the contents of each policy file:
cat ~/netpol/.yaml
Look for a policy that:
Has kind: NetworkPolicy
Applies to the backend namespace
Uses a podSelector that matches the backend pods
Includes an ingress.from rule that references the frontend namespace using a namespaceSelector (and optionally a podSelector)
Does not allow traffic from all namespaces or all pods
Here’s what to look for in a good match:
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
name: allow-frontend-to-backend
namespace: backend
spec:
podSelector:
matchLabels:
app: backend
ingress:
- from:
- namespaceSelector:
matchLabels:
name: frontend
Even better if the policy includes:
- namespaceSelector:
matchLabels:
name: frontend
podSelector:
matchLabels:
app: frontend
This limits access to pods in the frontend namespace with a specific label.
Step 5: Apply the correct NetworkPolicy
Once you’ve identified the best match, apply it:
kubectl apply -f ~/netpol/.yaml
Apply only one file. Do not alter or delete any existing sample.
ssh cka000056
kubectl get deployment -n frontend -o yaml
kubectl get deployment -n backend -o yaml
ls ~/netpol
cat ~/netpol/*.yaml # Review carefully
kubectl apply -f ~/netpol/.yaml
Command Summary
ssh cka000056
kubectl get deployment -n frontend -o yaml
kubectl get deployment -n backend -o yaml
ls ~/netpol
cat ~/netpol/*.yaml # Review carefully
kubectl apply -f ~/netpol/.yaml
