Ingress¶

Ingress is an API for HTTP and HTTPS routing into cluster services.

Important distinction:

Ingress resource: your routing rules
Ingress controller: implementation that enforces those rules

Without a controller, Ingress objects do nothing.

Typical traffic path¶

graph LR
  A[Client] --> B[External Load Balancer]
  B --> C[Ingress Controller]
  C --> D[Service]
  D --> E[Pods]

IngressClass and controller ownership¶

Set ingressClassName so the intended controller handles your object.

Common patterns:

one class for internet-facing traffic
one class for internal traffic

Ingress example¶

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: app-ingress
spec:
  ingressClassName: nginx
  tls:
    - hosts:
        - app.example.com
      secretName: app-example-tls
  rules:
    - host: app.example.com
      http:
        paths:
          - path: /api
            pathType: Prefix
            backend:
              service:
                name: api-service
                port:
                  number: 8080
          - path: /
            pathType: Prefix
            backend:
              service:
                name: web-service
                port:
                  number: 80

Path matching notes¶

Prefix: best for most route trees
Exact: strict path match
ImplementationSpecific: controller-defined behavior, use carefully

TLS operations¶

Ingress commonly terminates TLS at the controller. Certificates are referenced from Kubernetes secrets.

For managed cert lifecycle, use cert-manager or your platform-native certificate workflow.

Common issues¶

wrong ingressClassName
backend service name or port mismatch
no healthy endpoints behind the backend service
DNS not pointing to controller entrypoint

Quick debug checklist¶

kubectl get ingress -A
kubectl describe ingress app-ingress
kubectl get svc -A
kubectl get endpointslices -A
kubectl logs -n ingress-nginx deploy/ingress-nginx-controller

Ingress vs Gateway API¶

Ingress remains widely used and practical for straightforward HTTP routing.

Gateway API is better when you need:

clearer platform and app ownership boundaries
richer policy and traffic controls
multi-team self-service at scale

Summary¶

Ingress is the standard entry point for HTTP and HTTPS in many Kubernetes platforms. Keep configuration explicit, validate controller ownership, and monitor route behavior as part of day-2 operations.