Ingress: One Entry Point for Many Services

A Service of type LoadBalancer costs one cloud load balancer per service. An Ingress routes many hosts and paths through one.

flowchart LR
  U[Users] --> LB[Cloud load balancer]
  LB --> IC[Ingress controller]
  IC --> A[Service web]
  IC --> B[Service api]

An Ingress object is only a set of rules; an ingress controller (for example ingress-nginx) must be installed to act on them.

helm repo add ingress-nginx https://kubernetes.github.io/ingress-nginx
helm install ingress ingress-nginx/ingress-nginx -n ingress --create-namespace

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

Since 1.22 only the v1 API exists. Point DNS for app.example.com at the controller’s load balancer address.