Networking: Services, DNS, and IngressLesson 3.3

Kubernetes Ingress: how to route HTTP traffic to multiple services

Ingress resource, Ingress controller, path-based routing, host-based routing, TLS termination, nginx ingress controller, IngressClass, backend service reference

Ingress Routes External HTTP to Internal Services

Rather than creating one LoadBalancer per Service (expensive), Ingress lets a single entry point route HTTP/HTTPS traffic to multiple Services based on path or hostname.

Install nginx Ingress Controller (kind)

kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/main/deploy/static/provider/kind/deploy.yaml

# Wait for it to be ready
kubectl wait --namespace ingress-nginx   --for=condition=ready pod   --selector=app.kubernetes.io/component=controller   --timeout=90s

Path-Based Routing

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