Understanding Kubernetes: Part 18 -Ingress Controller

If you’ve been following our Kubernetes series 2025, welcome back! For new readers, check out Part 16: Understanding Kubernetes: Ingress

📖 Not a Medium member? No worries! Here’s the free link: Part 18 — Ingress Controller

What is an Ingress Controller in Kubernetes?

An Ingress Controller is a component in Kubernetes responsible for implementing the Ingress resource, processing its rules, and directing traffic accordingly. It acts as a reverse proxy, routing HTTP/HTTPS traffic based on defined Ingress rules. While an Ingress resource defines how traffic should be routed, the Ingress Controller enforces those rules and manages actual traffic flow within the cluster.

Kubernetes does not provide a default Ingress Controller; users need to deploy one such as Nginx, Traefik, HAProxy, AWS ALB, or GCP HTTP(S) Load Balancer based on their infrastructure requirements.

Example Use Case:

Suppose you have an Ingress resource configured to expose multiple microservices under a single domain. The Ingress Controller (e.g., Nginx) will:

• Listen to external traffic requests on port 80/443.
• Analyze the Ingress resource configuration.