NGINX Ingress Rewrite Target 404

You encounter a nginx configuration issue that prevents your workflow from completing. This guide walks through the fix step by step.

Wrong ❌

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: "/$2"
    nginx.ingress.kubernetes.io/use-regex: "true"
spec:
  rules:
    - host: api.example.com
      http:
        paths:
          - path: /api/v1(/|$)(.*)
            pathType: ImplementationSpecific
            backend: { service: { name: api-service, port: { number: 80 } } }

Wrong Output

All requests 404. Backend receives wrong path from capture group.

Right ✅

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: "/v2/$2"
    nginx.ingress.kubernetes.io/use-regex: "true"
spec:
  rules:
    - host: api.example.com
      http:
        paths:
          - path: /api(/|$)(.*)
            pathType: ImplementationSpecific
            backend: { service: { name: api-service, port: { number: 80 } } }

Right Output

Rewrite: /api/v2/users -> /v2/users -> 200 OK. Capture group works.

Prevention

• Use ImplementationSpecific for regex rewrite rules.
• Enable use-regex annotation.
• Test regex patterns before deploying.
• Ensure capture groups match the intended URL part.
• Check backend path expectations.

DodaTech applies similar defensive patterns across Doda Browser, DodaZIP, and Durga Antivirus Pro infrastructure for production reliability.

Common Mistakes with ingress rewrite target

1. Overlapping type class instances that cause GHC to reject the program with ambiguous dispatch errors
2. Non-exhaustive pattern matches that compile with warnings then crash at runtime
3. Misunderstanding that String is [Char] with poor performance for large text operations

These mistakes appear frequently in real-world NGINX code. DodaTech's contributors have identified these patterns through analysis of open-source projects and production systems.

Practice Exercise

Write a pure function that safely divides two integers using Maybe, then test it with edge cases like division by zero and negative numbers.

This exercise reinforces the concepts covered in this guide. Try implementing it before checking online solutions.

FAQ

This quick fix is part of the DodaTech infrastructure engineering series. Learn more at DodaTech tutorials.