Ingress and the Gateway API

Ingress

An Ingress routes HTTP(S) traffic by host and path to Services. It needs an Ingress controller (ingress-nginx, Traefik, a cloud load balancer controller) running in the cluster:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata: {name: shop}
spec:
  ingressClassName: nginx
  tls: [{hosts: [shop.example.com], secretName: shop-tls}]
  rules:
    - host: shop.example.com
      http:
        paths:
          - {path: /api, pathType: Prefix, backend: {service: {name: api, port: {number: 80}}}}
          - {path: /, pathType: Prefix, backend: {service: {name: web, port: {number: 80}}}}

Gateway API

The Gateway API (Gateway, HTTPRoute) is the newer, more expressive successor: roles are split between platform teams (Gateways) and app teams (routes), and features like header matching and traffic splitting are standard rather than controller-specific annotations.

cat > ingress.yaml <<'EOF'
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: shop
spec:
  ingressClassName: nginx
  rules:
    - host: shop.example.com
      http:
        paths:
          - path: /api
            pathType: Prefix
            backend:
              service: {name: api, port: {number: 80}}
  defaultBackend:
    service: {name: web, port: {number: 80}}
EOF
kubeconform -strict -summary ingress.yaml
sed -i 's/pathType: Prefix/pathType: Startswith/' ingress.yaml
kubeconform -strict ingress.yaml 2>&1 | sed -E 's/.*(pathType)/  \1/' | head -2 || true

Summary: 1 resource found in 1 file - Valid: 1, Invalid: 0, Errors: 0, Skipped: 0

See Ingress and Gateway API.