GKE ingress-nginx rewrite-target contains invalid path

Question

I am using GKE (Autopilot, version: v1.25.5-gke.2000) and replaced the "GCE" native load balancer with "ingress-nginx" (Helm version 4.5.0). In general, ingress is working as long I don't use the rewrite-target.

Here is my Ingress config:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress-nginx
  namespace: something
  annotations:
    kubernetes.io/ingress.class: "nginx"
    nginx.ingress.kubernetes.io/ssl-redirect: "false"
    nginx.ingress.kubernetes.io/rewrite-target: /$2
spec:
  tls:
  - secretName: ingress-ssl
    hosts:
    - host.example.com
  rules:
  - host: host.example.com
    http:
      paths:
      - path: "/admin/portal(/|$)(.*)"
        pathType: Prefix
        backend:
          service:
            name: api-service
            port:
              name: http
      - path: /
        pathType: Prefix
        backend:
          service:
            name: api-service
            port:
              name: http

By doing so I get this log message: "successfully validated configuration, accepting" ingress="something/ingress-nginx" followed by ingress something/ingress-nginx contains invalid path /admin/portal(/|$)(.*)

What am I doing wrong? The non regex pattern works by calling /swagger/index.html but calling but host.example.com/admin/portal/swagger.index.html does not.

Answer 1

Today a new helm version 4.5.2 was released fixing the issue in helm chart 4.5.0

https://github.com/kubernetes/ingress-nginx/releases Revert Implement pathType validation (#9511) (#9607)

https://github.com/kubernetes/ingress-nginx/pull/9511 helm release 4.5.0 broke regex in path #9616