Ingress vs LoadBalancer Service decision in Kubernetes - CLI Comparison

Introduction

When you want to expose your applications running in Kubernetes to the outside world, you need a way to route external traffic. Ingress and LoadBalancer services are two common methods to do this, each solving different problems about how traffic reaches your app.

When you have multiple services and want to route traffic to them using one external IP with different URLs or paths.

When you want a simple way to expose a single service directly to the internet with its own IP address.

When you want to use advanced routing rules like SSL termination or host-based routing.

When your cloud provider supports automatic external load balancers for services.

When you want to reduce the number of public IPs used by sharing one IP across many services.

Commands

This command creates a Service of type LoadBalancer that exposes your app with a cloud provider's external IP address.

Terminal

kubectl apply -f loadbalancer-service.yaml

Expected Output

service/my-loadbalancer-service created

This command checks the status of the LoadBalancer service and shows the external IP assigned by the cloud provider.

Terminal

kubectl get svc my-loadbalancer-service

Expected Output

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

my-loadbalancer-service  LoadBalancer   10.96.0.1       34.123.45.67     80:32456/TCP   1m

This command creates an Ingress resource that routes external traffic to different services based on rules like URL paths or hostnames.

Terminal

kubectl apply -f ingress.yaml

Expected Output

ingress.networking.k8s.io/my-ingress created

This command shows the external IP or hostname assigned to the Ingress controller that handles routing traffic to your services.

Terminal

kubectl get ingress my-ingress

Expected Output

NAME         CLASS    HOSTS               ADDRESS          PORTS   AGE

my-ingress   <none>   example.com         34.123.45.89     80      1m

Key Concept

If you remember nothing else from this pattern, remember: Use LoadBalancer service for simple direct exposure of one app, and use Ingress to route traffic to many apps with one external IP and flexible rules.

Common Mistakes

Creating multiple LoadBalancer services for many apps without considering IP limits.

Cloud providers limit the number of external IPs and it can be costly or inefficient.

Use an Ingress resource to share one external IP and route traffic to multiple services.

Applying an Ingress resource without installing an Ingress controller.

Ingress resources need a controller to actually route traffic; without it, the Ingress does nothing.

Install a supported Ingress controller like NGINX Ingress or cloud provider's controller before creating Ingress resources.

Summary

Use LoadBalancer service to expose a single app with its own external IP.

Use Ingress to route traffic to multiple services using one external IP and rules.

Check service or ingress status with kubectl get commands to find assigned external IPs.