What is Ingress in Kubernetes?

What is Ingress in Kubernetes?

Ingress is a Kubernetes resource that manages external access to your cluster’s services, typically over HTTP/HTTPS.

It acts like a smart router or reverse proxy inside your cluster.

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Why Not Just Use NodePort or LoadBalancer?

• NodePort

  • Drawback: Exposes service on a random high port of every node. Not scalable or friendly for users.

• LoadBalancer

  • Drawback: Each service gets its own external IP (expensive and cluttered).

Ingress solves this by:

• Letting you route multiple paths/domains through a single IP
• Giving you TLS/HTTPS support
• Making it easier to manage routing rules in one place

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When to Use Ingress

Use Ingress when:

• You want to expose multiple services through one IP/domain
• You want pretty URLs, like:
  • example.com/api
  • example.com/app
• You need TLS/HTTPS termination
• You want centralized traffic routing logic

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Ingress Architecture

Internet
   |
Ingress Controller (e.g., NGINX, GKE Ingress)
   |
   |-- /app   --> app-service
   |-- /api   --> api-service

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How to Set Up Ingress (Basic Steps)

1. Install an Ingress Controller (NGINX, GKE Ingress, etc.)

   • Example for Minikube:

     minikube addons enable ingress
     

2. Create Services for your apps:

   kubectl expose deployment my-app --port=80 --target-port=8080
   

3. Define Ingress resource YAML:

   apiVersion: networking.k8s.io/v1
   kind: Ingress
   metadata:
     name: my-ingress
     annotations:
       nginx.ingress.kubernetes.io/rewrite-target: /
   spec:
     rules:
     - host: myapp.local
       http:
         paths:
         - path: /
           pathType: Prefix
           backend:
             service:
               name: my-app
               port:
                 number: 80
   

4. Access via /etc/hosts (for Minikube):

   192.168.49.2 myapp.local
   

5. Test in browser or curl:

   curl http://myapp.local
   

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Popular Ingress Controllers

• NGINX Ingress Controller (most common)
• GKE Ingress Controller (if you're on GKE)
• Traefik, Istio Gateway, etc.