Ingress controllers (Nginx, Traefik) in Kubernetes - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

Nginx Ingress Controller Pod Status

You deployed an Nginx Ingress Controller in your Kubernetes cluster. What is the output of the command kubectl get pods -n ingress-nginx immediately after deployment?

Kubernetes

kubectl get pods -n ingress-nginx

A

NAME                                        READY   STATUS    RESTARTS   AGE
nginx-ingress-controller-abc123               1/1     CrashLoopBackOff   3          1m

B

NAME                                        READY   STATUS    RESTARTS   AGE
nginx-ingress-controller-abc123               0/1     Pending   0          1m

C

NAME                                        READY   STATUS    RESTARTS   AGE
nginx-ingress-controller-abc123               1/1     Running   0          1m

D Error from server (NotFound): namespaces "ingress-nginx" not found

💡 Hint

Think about the normal state of a pod right after a successful deployment.

After a successful deployment, the Nginx Ingress Controller pod should be in Running state with all containers ready (1/1). Pending means it hasn't started, CrashLoopBackOff means it is failing repeatedly, and NotFound means the namespace doesn't exist.

🧠 Conceptual

intermediate

Traefik Ingress Controller Feature

Which feature is unique to Traefik compared to Nginx Ingress Controller in Kubernetes?

A Does not support Let's Encrypt integration

B Supports only HTTP and HTTPS protocols

C Requires manual configuration reload after changes

D Automatic service discovery and dynamic configuration without reload

💡 Hint

Think about how Traefik handles configuration updates.

Traefik automatically discovers services and updates its routing configuration dynamically without needing to reload, unlike Nginx which often requires reloads.

❓ Troubleshoot

advanced

Nginx Ingress Controller TLS Issue

You configured TLS for your Nginx Ingress Controller, but HTTPS requests fail with a certificate error. Which of the following is the most likely cause?

A The TLS secret referenced in the Ingress resource does not exist or is in the wrong namespace

B The Ingress controller does not support TLS

C The Ingress resource is missing the host field

D The service port is not exposed as NodePort

💡 Hint

Check the TLS secret and its namespace carefully.

TLS requires a valid secret with the certificate and key in the same namespace as the Ingress resource. If the secret is missing or in another namespace, the certificate error occurs.

🔀 Workflow

advanced

Deploying Traefik with Helm

Which Helm command correctly installs Traefik Ingress Controller in the namespace 'traefik-system' with default settings?

A helm deploy traefik traefik/traefik --namespace traefik-system

B helm install traefik traefik/traefik --namespace traefik-system --create-namespace

C helm install traefik traefik/traefik --namespace default

D helm apply traefik traefik/traefik --namespace traefik-system

💡 Hint

Remember the correct Helm command to install a chart and create namespace if missing.

The correct Helm command to install a chart is 'helm install'. The '--create-namespace' flag creates the namespace if it doesn't exist. 'helm deploy' and 'helm apply' are invalid Helm commands.

✅ Best Practice

expert

Securing Ingress Controllers

What is the best practice to secure your Kubernetes cluster's Ingress Controller against unauthorized external access?

A Use Network Policies to restrict traffic to the Ingress Controller pods

B Expose the Ingress Controller service as LoadBalancer without firewall rules

C Disable TLS to simplify configuration

D Allow all incoming traffic to the Ingress Controller

💡 Hint

Think about controlling network traffic at the pod level.

Network Policies allow you to restrict which pods or IPs can communicate with the Ingress Controller, enhancing security. Exposing without restrictions or disabling TLS weakens security.