LoadBalancer service type in Kubernetes - Commands & Configuration

Introduction

Sometimes you want your app to be reachable from outside your cluster. The LoadBalancer service type creates a network load balancer that routes external traffic to your app automatically.

When you want to expose a web app running in Kubernetes to the internet with a stable IP address.

When you need to distribute incoming traffic evenly across multiple app instances.

When you want cloud provider integration to automatically create a load balancer for your service.

When you want to avoid manually configuring external routers or firewalls.

When you want a simple way to get external access without complex networking setup.

Config File - loadbalancer-service.yaml

loadbalancer-service.yaml

apiVersion: v1
kind: Service
metadata:
  name: example-loadbalancer
spec:
  type: LoadBalancer
  selector:
    app: example-app
  ports:
    - protocol: TCP
      port: 80
      targetPort: 8080

This file defines a Service named example-loadbalancer that exposes pods with label app: example-app.

The type: LoadBalancer tells Kubernetes to create an external load balancer.

The service listens on port 80 and forwards traffic to port 8080 on the pods.

Commands

This command creates the LoadBalancer service in your Kubernetes cluster using the configuration file.

Terminal

kubectl apply -f loadbalancer-service.yaml

Expected Output

service/example-loadbalancer created

This command checks the status of the LoadBalancer service and shows its external IP once assigned.

Terminal

kubectl get services example-loadbalancer

Expected Output

NAME                  TYPE           CLUSTER-IP      EXTERNAL-IP      PORT(S)        AGE

example-loadbalancer   LoadBalancer   10.96.123.45    34.123.45.67    80:31234/TCP   10s

This command shows detailed information about the LoadBalancer service, including endpoints and events.

Terminal

kubectl describe service example-loadbalancer

Expected Output

Name:                     example-loadbalancer

Namespace:                default

Labels:                   <none>

Annotations:              <none>

Selector:                 app=example-app

Type:                     LoadBalancer

IP:                       10.96.123.45

LoadBalancer Ingress:     34.123.45.67

Port:                     <unset>  80/TCP

TargetPort:               8080/TCP

Endpoints:                192.168.1.10:8080,192.168.1.11:8080

Session Affinity:         None

Events:

  Type    Reason                Age   From                Message

  ----    ------                ----  ----                -------

  Normal  EnsuringLoadBalancer  10s   service-controller  Ensuring load balancer

  Normal  EnsuredLoadBalancer   5s    service-controller  Ensured load balancer

Key Concept

If you remember nothing else from this pattern, remember: the LoadBalancer service type automatically creates an external IP to route traffic to your app pods.

Common Mistakes

Using LoadBalancer service type on a local Kubernetes cluster without cloud provider support.

Local clusters like minikube or kind do not support automatic external load balancers, so the EXTERNAL-IP stays pending.

Use NodePort or port forwarding for local clusters, or use a cloud Kubernetes service for LoadBalancer support.

Not labeling pods with the selector labels defined in the service.

The service cannot find any pods to route traffic to, so no endpoints are available.

Ensure pods have the correct labels matching the service selector.

Summary

Create a LoadBalancer service YAML file to expose your app externally.

Apply the service with kubectl apply to create it in the cluster.

Check the service status and external IP with kubectl get services.

Use kubectl describe to see detailed info and troubleshoot.