LoadBalancer service type in Kubernetes - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

What does a LoadBalancer service type do in Kubernetes?

In Kubernetes, what is the main purpose of a service with type LoadBalancer?

A It exposes the service externally using a cloud provider's load balancer and assigns a public IP.

B It only exposes the service inside the cluster without any external access.

C It creates a DNS record for the service but does not expose it externally.

D It automatically scales the number of pods based on incoming traffic.

💡 Hint

Think about how external users can access your service from outside the cluster.

A LoadBalancer service type creates an external load balancer in supported cloud providers, giving the service a public IP address for external access.

💻 Command Output

intermediate

Output of kubectl get svc for LoadBalancer service

What is the expected output of kubectl get svc for a LoadBalancer service just created in a cloud environment?

Kubernetes

kubectl get svc my-loadbalancer-service

A

NAME                   TYPE           CLUSTER-IP      EXTERNAL-IP      PORT(S)          AGE
my-loadbalancer-service NodePort       10.0.0.1       <none>           80:30080/TCP     5m

B

NAME                   TYPE           CLUSTER-IP      EXTERNAL-IP      PORT(S)          AGE
my-loadbalancer-service LoadBalancer   10.0.0.1       <pending>        80:30080/TCP     5m

C

NAME                   TYPE           CLUSTER-IP      EXTERNAL-IP      PORT(S)          AGE
my-loadbalancer-service ClusterIP     10.0.0.1       <none>           80/TCP           5m

D

NAME                   TYPE           CLUSTER-IP      EXTERNAL-IP      PORT(S)          AGE
my-loadbalancer-service LoadBalancer   10.0.0.1       35.226.14.5      80:30080/TCP     5m

💡 Hint

Just after creation, the cloud provider has not yet provisioned the load balancer.

Immediately after creating a LoadBalancer service in a cloud environment, the EXTERNAL-IP shows <pending> until the cloud provider provisions the load balancer.

❓ Configuration

advanced

Correct YAML for a LoadBalancer service

Which YAML snippet correctly defines a Kubernetes service of type LoadBalancer exposing port 80?

A

apiVersion: v1
kind: Service
metadata:
  name: my-service
spec:
  type: LoadBalancer
  selector:
    app: myapp
  ports:
    - protocol: TCP
      port: 80
      targetPort: 80

B

apiVersion: v1
kind: Service
metadata:
  name: my-service
spec:
  type: NodePort
  selector:
    app: myapp
  ports:
    - protocol: TCP
      port: 80
      targetPort: 80

C

apiVersion: v1
kind: Service
metadata:
  name: my-service
spec:
  type: ClusterIP
  selector:
    app: myapp
  ports:
    - protocol: TCP
      port: 80
      targetPort: 80

D

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1v :noisreVipa

💡 Hint

Check the service type and protocol used for HTTP traffic.

The correct YAML uses type: LoadBalancer and TCP protocol for port 80, which is standard for HTTP.

❓ Troubleshoot

advanced

Why is EXTERNAL-IP stuck at <pending>?

You created a LoadBalancer service in Kubernetes, but kubectl get svc shows <pending> in the EXTERNAL-IP column. What is the most likely cause?

A The pod is crashing and restarting continuously.

B The service selector labels do not match any pods.

C The service port is not exposed in the pod containers.

D The Kubernetes cluster is running on a local machine or environment without a cloud provider integration.

💡 Hint

Think about what provisions the external IP for LoadBalancer services.

LoadBalancer services require cloud provider support to provision an external IP. On local clusters like Minikube or bare metal, this IP stays pending.

🔀 Workflow

expert

Steps to expose an app externally using LoadBalancer service

What is the correct order of steps to expose a Kubernetes app externally using a LoadBalancer service?

A 2,1,3,4

B 3,1,2,4

C 1,2,3,4

D 1,3,2,4

💡 Hint

Create both YAML files before applying them to the cluster.

The logical order is to first create the Deployment YAML, then define the Service YAML selecting the Deployment's pods, then apply both YAML files to the cluster, and finally check the EXTERNAL-IP once provisioned.