Before You Migrate: Five Surprising Ingress-NGINX Behaviors You Need to Know

This post highlights five surprising Ingress-NGINX behaviors to be aware of before migrating to Gateway API, as Ingress-NGINX is being retired by Kubernetes in March 2026.

• •Regex path matches in Ingress-NGINX are prefix-based and case-insensitive by default, meaning /[A-Z]{3} also matches /uuid or /abc unexpectedly.
• •The nginx.ingress.kubernetes.io/use-regex annotation on one Ingress affects all Ingresses sharing the same host, enabling unintended regex behavior cluster-wide.
• •Adding a rewrite-target annotation silently enables regex behavior for all paths on that host, even without an explicit use-regex annotation.
• •These quirks can cause outages during migration if Gateway API implementations apply full, case-sensitive regex matches instead.

This summary was automatically generated by AI based on the original article and may not be fully accurate.