advanced

Ingress

Route external HTTP traffic to services through host, path, TLS, controller, and edge policy configuration.

Ingress describes HTTP routing from outside the cluster to internal Services. Actual behavior comes from an ingress controller (NGINX, Traefik, cloud LB integrations) handling TLS, hosts, paths, rewrites, and annotations.

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

Gateway API is the newer alternative for complex L4/L7 routing, but Ingress remains common in interviews.

On interviews: ingress resource vs controller vs cloud load balancer; TLS termination; path matching; canary routing; controller-specific annotations.

Common pitfalls: manifests that work on one controller break on another; misconfigured TLS or paths expose or break routes.

The trade-off is portable YAML versus controller features that require vendor-specific annotations.

Checklist:

Know which controller runs in the cluster.
Configure TLS and hosts explicitly.
Test routing rules end to end.
Compare Ingress with Gateway API for greenfield designs.