Kubernetes Ingress

• Install nginx-ingress via helm: helm install ingress-nginx ingress-nginx/ingress-nginx
• cert-manager + ClusterIssuer issues certs automatically
• Path-based routing: /api → api-svc, /web → web-svc
• Rate-limit: nginx.ingress.kubernetes.io/limit-rps: "10"
• Alternative: Gateway API (K8s 1.29+) — more expressive, will replace Ingress

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: api
  annotations:
    cert-manager.io/cluster-issuer: letsencrypt
    nginx.ingress.kubernetes.io/limit-rps: "10"
spec:
  ingressClassName: nginx
  tls:
    - hosts: [api.example.com]
      secretName: api-tls
  rules:
    - host: api.example.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service: { name: api-svc, port: { number: 80 } }

• K8s Gateway API
• CDN setup

To configure Ingress in Kubernetes, you must first deploy an Ingress controller, define an Ingress resource with the appropriate rules to route traffic, and ensure your services are accessible. This allows external HTTP/S traffic to reach your Kubernetes services based on defined hostnames and paths.

Before you can set up Ingress resources, you need to deploy an Ingress controller. The Ingress controller is responsible for managing the traffic routing rules defined in your Ingress resources. Popular options include NGINX Ingress Controller and Traefik. Below is an example of deploying the NGINX Ingress Controller using Helm:

helm repo add ingress-nginx https://kubernetes.github.io/ingress-nginx
helm repo update
helm install my-nginx ingress-nginx/ingress-nginx

This command installs the NGINX Ingress Controller with the release name `my-nginx`. You can verify the installation with:

kubectl get pods -n ingress-nginx

Make sure your Kubernetes cluster has the necessary permissions and configurations to allow this deployment. After the installation, the Ingress controller will create a service of type LoadBalancer (if running on a cloud provider) to expose the ingress traffic.

Once the Ingress controller is up and running, you can create Ingress resources to define how requests should be routed to your services. Here’s an example of an Ingress resource definition:

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

In this example, the Ingress resource named `my-ingress` routes traffic for `myapp.example.com` to a service named `my-service` on port 80. The `pathType` is set to `Prefix`, meaning any request starting with `/` will be directed to the defined backend service.

To apply this configuration, save the above YAML to a file named `ingress.yaml` and run:

kubectl apply -f ingress.yaml

After applying, you can check the Ingress resource status using:

kubectl get ingress my-ingress

Ensure that your DNS is configured to point `myapp.example.com` to the external IP of the Ingress controller service. You can find the external IP using:

kubectl get services -n ingress-nginx

By following these steps, you will successfully configure Ingress in Kubernetes, allowing external traffic to reach your services based on specified rules.