The Basics of Ingress: Key Information

Ingress is a Kubernetes resource that manages external access to services within a cluster, typically HTTP/HTTPS. It provides a unified way to define routing rules, SSL termination, and virtual hosts.

Why Ingress?

It's Helps

• Centralized Routing: Manage all external traffic routing in one place.

• SSL Termination: Handle SSL/TLS termination for secure communication.

• Load Balancing: Distribute traffic evenly across multiple pods.

• Path-Based Routing: Route traffic to different services based on URL paths.

• Host-Based Routing: Serve multiple applications using the same IP address based on the host header.

Components of Ingress

1) Ingress Resource:

• Defines the rules for routing traffic.

• an specify multiple rules for different hosts and paths.

2) Ingress Controller:

• Manages the Ingress resources.

• Implements the actual routing and load balancing.

• Common controllers include Nginx, Traefik, and HAProxy.

Let's take Demo with real world

1) Enable Ingress in Minikube:

minikube addons enable ingress

2) Define Kubernetes Resources:

• Deployment: Manages the application pods.

• Service: Exposes the application pods internally within the cluster.

• Ingress: Defines how external traffic is routed to the services.

Example Configurations

Deployment (deployment.yaml)

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-portfolio
spec:
  replicas: 3
  selector:
    matchLabels:
      app: my-portfolio
  template:
    metadata:
      labels:
        app: my-portfolio
    spec:
      containers:
      - name: my-portfolio
        image: youknowwhoitssaymon/my-portfolio:latest
        ports:
        - containerPort: 80

Service (service.yaml)

apiVersion: v1
kind: Service
metadata:
  name: my-portfolio-service
spec:
  type: ClusterIP
  selector:
    app: my-portfolio
  ports:
    - protocol: TCP
      port: 80
      targetPort: 80

Ingress (ingress.yaml)

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

Traffic Flow in Ingress

1)DNS Resolution:

• Client sends a request to http://my-portfolio.local.

• The local DNS resolves my-portfolio.local to the Minikube IP address.

2)Ingress Controller:

• The request reaches the Nginx Ingress Controller running in the Minikube cluster.

• The Ingress Controller inspects the host and path of the request.

3)Ingress Resource:

• The Ingress resource defines routing rules based on the host (my-portfolio.local) and path (/).

• Matches the incoming request to the correct backend service (my-portfolio-service).

4)Service:

• The service routes the request to one of the pods running the application.

• Load balances traffic among available pods.

5)Pod:

• The selected pod processes the request.

• The pod serves the response back to the client through the service and ingress controller.

Updating Local Hosts File

To access your application via the defined hostname, update your local hosts file:

1)Get Minikube IP:

minikube ip

2)Edit Hosts File:

Add an entry to your local hosts file (usually located at /etc/hosts on macOS/Linux or C:\Windows\System32\drivers\etc\hosts on Windows):

<minikube-ip> my-portfolio.local

Replace with the actual IP address from the minikube ip command.

open on your browser: http://my-portfolio.local.