Ingress NGINX

It's the official NGINX-based ingress controller maintained by the Kubernetes project. You define routing rules in YAML, and it configures NGINX to make them happen.

Apache 2.0. Handles TLS termination, rate limiting, basic auth, WebSocket proxying, and canary deployments. Pairs with cert-manager for automatic Let's Encrypt certificates.

Fully free. No paid tier. This is community infrastructure maintained by the Kubernetes SIG.

The catch: NGINX config through Kubernetes annotations is clunky. Complex routing rules turn into annotation soup that's hard to debug. Performance is solid for most workloads, but if you need advanced traffic management (circuit breaking, retries with budgets, traffic mirroring), you'll outgrow it. And there's a confusing namespace issue: this is kubernetes/ingress-nginx (community), not nginxinc/kubernetes-ingress (NGINX Inc's commercial version). Make sure you install the right one.