Can you explain what Kubernetes Ingress is and how it works for routing external traffic?

Kubernetes Ingress is an object in Kubernetes that manages external access to services within a cluster, usually via HTTP/HTTPS. Ingress allows defining routing rules that direct incoming traffic to the appropriate services based on URL, host, or other parameters.

Ingress works together with the Ingress Controller — a component that implements these rules and handles the traffic. For example, you can configure Ingress so that requests to example.com/api go to one service, and requests to example.com/web go to another.

An example of a simple Ingress manifest:

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

Thus, Ingress simplifies external access management and allows flexible traffic routing within the cluster.