Ingress and Ingress controllers play a pivotal role in the Kubernetes ecosystem by managing external access to services within a cluster. They offer HTTP and HTTPS routing to services based on hostname or URL paths, providing a level of control and efficiency beyond basic service types like NodePort or LoadBalancer.

Understanding Ingress in Kubernetes

What is Ingress?

In Kubernetes, an Ingress resource provides an entry point for external HTTPS/HTTP traffic into the cluster. It defines the rules for routing requests to the appropriate backend services, making it possible to implement host-based and path-based routing.

Key Features of Ingress

• Path-based Routing: Routes traffic to backend services based on URL path segments.
• Host-based Routing: Routes traffic to specific services based on the host specified in the HTTP request.
• TLS/SSL Termination: Terminates SSL/TLS at the edge of the cluster, reducing the SSL load on backend services.
• Load Balancing: Distributes incoming traffic across multiple backend pods.

Ingress Controller: The Power Behind the Resource

What is an Ingress Controller?

An Ingress Controller is a specialized load balancer that implements the Ingress API and routes traffic into a Kubernetes cluster based on Ingress Resource configurations. It is capable of customizing handling by extensions like annotation and can provide additional features such as rate limiting or Web Application Firewall (WAF) integrations.

Popular Ingress Controllers

Several Ingress Controllers are available, such as:

• NGINX Ingress Controller: Uses NGINX to deliver high-performance, reliable routing.
• HAProxy Ingress: Known for its advanced routing capabilities.
• Traefik: Comes with dynamic routing configuration and integrated Let's Encrypt support.

Using Ingress with NodePort Services

What is a NodePort?

A NodePort service exposes a service on each Node's IP at a static port. It provides a simple way to access a service externally but is less sophisticated compared to LoadBalancer and Ingress.

Why Combine Ingress with NodePort?

Combining Ingress with NodePort can optimize external traffic routing by centralizing configuration into Ingress while benefiting from NodePort's minimal setup requirements. It also sidesteps the need for cloud-provider-specific load balancer setups, offering more consistent behavior across environments.

Example Setup

Prerequisites: A running Kubernetes cluster and kubectl configured.

1. Deploy a Simple Application: Let's deploy a basic Nginx application using a NodePort service:
   • port: 80
     • name: nginx
       • containerPort: 80
   • host: example.com
     • path: /