How to configure Kubernetes Ingress?

Understanding Kubernetes Ingress

Kubernetes Ingress is a Kubernetes resource that provides a way to manage external access to the services running in a Kubernetes cluster. It acts as a reverse proxy, handling incoming HTTP and HTTPS traffic and routing it to the appropriate services within the cluster.

Ingress Components

To configure Kubernetes Ingress, you need to understand the following key components:

Ingress Controller: The Ingress Controller is a Kubernetes controller that watches the Ingress resources and configures the load balancer accordingly. There are several Ingress Controller implementations available, such as Nginx Ingress Controller, Traefik, and Istio Ingress Gateway.
Ingress Resource: The Ingress resource is a Kubernetes object that defines the rules for routing incoming traffic to the appropriate services within the cluster. It specifies the host, path, and service information for each incoming request.
Ingress Rules: Ingress rules define how incoming traffic should be routed to the appropriate services. These rules can be based on the host (domain name) and/or the URL path.
Ingress Backend: The Ingress backend is the Kubernetes service that will receive the traffic routed by the Ingress. It is responsible for handling the incoming requests and forwarding them to the appropriate pods.

Configuring Kubernetes Ingress

To configure Kubernetes Ingress, follow these steps:

Install an Ingress Controller: First, you need to install an Ingress Controller in your Kubernetes cluster. The most popular choice is the Nginx Ingress Controller, which can be installed using Helm or by applying a YAML manifest.

graph LR A[Kubernetes Cluster] --> B[Ingress Controller] B --> C[Ingress Resource] C --> D[Ingress Backend] D --> E[Kubernetes Service] E --> F[Kubernetes Pods]

Create an Ingress Resource: Next, you need to create an Ingress resource that defines the routing rules for your services. Here's an example Ingress resource:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: example-ingress
spec:
  rules:
  - host: example.com
    http:
      paths:
      - path: /api
        pathType: Prefix
        backend:
          service:
            name: api-service
            port:
              number: 80
      - path: /web
        pathType: Prefix
        backend:
          service:
            name: web-service
            port:
              number: 80

In this example, the Ingress resource routes traffic to two different services based on the URL path: /api goes to the api-service, and /web goes to the web-service.

Configure the Ingress Backend: The Ingress backend is the Kubernetes service that will receive the traffic routed by the Ingress. Make sure that your backend services are properly configured and exposed within the cluster.
Expose the Ingress Controller: Finally, you need to expose the Ingress Controller to the outside world. This can be done by creating a Kubernetes Service of type LoadBalancer or NodePort that points to the Ingress Controller.

By following these steps, you can configure Kubernetes Ingress to manage external access to your services running within the Kubernetes cluster.