Kubernetes Ingress

Route HTTP and HTTPS traffic into your cluster with Ingress rules, controllers, TLS termination, and host or path based routing.

What Is Ingress?

An Ingress is a Kubernetes API resource for HTTP and HTTPS routing. It does not handle traffic by itself. An Ingress Controller such as NGINX or Traefik watches Ingress resources and implements the routing behavior.

Why Use Ingress?

Ingress lets you:

route by host name
route by URL path
terminate TLS centrally
share one public entry point across many services

Ingress vs LoadBalancer Service

Topic	Ingress	LoadBalancer Service
Routing level	Layer 7 HTTP/HTTPS	Layer 4 network exposure
Multiple apps	Great fit	Often one LB per Service
TLS termination	Common feature	Possible but less centralized
Path routing	Yes	No native path rules

Traffic Diagram

Internet → Ingress Controller → Services → Pods

Internet

app.example.com

HTTP/HTTPS

Ingress Controller

NGINX / Traefik

/api → api-service:80

/web → web-service:80

routes by path/host

Service

api-service

api-pod-1, api-pod-2

Service

web-service

web-pod-1, web-pod-2

Path-Based Routing Example

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

Host-Based Routing Example

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

TLS Termination Example

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

Why the Controller Matters

Without an Ingress Controller, the Ingress resource is only a rule definition. The controller is the actual traffic manager.

Think of Ingress as the route map and the Ingress Controller as the traffic police who enforce it.

Exercise

Controller Need

Why is an Ingress Controller required?

Exercise

Path Routing

Which Kubernetes resource is best suited for routing `/api` to one service and `/` to another over HTTP?