Backend returns 404 after Access Gateway upgrade from 12.8 to 12.9

Products

• SITEMINDER

Issue/Introduction

Following error is seen after upgrade to 12.9,

[Response status code from backend webserver is 404]

Environment

Access Gateway: 12.9

Backend is on EKS kubernetes

Cause

The backend is on EKS kubernetes, there is a virtual service configured to route the traffic to the backend.

The matching rule is like:

  http:
  - match:
    - uri:
        prefix: /

This is working before, but now those uri start with /images, etc. cannot reach the backend and returns 404

Resolution

In the yaml file of the virtual service, add few more path patterns, shown as below, and it works now.

Additional Information

As per https://istio.io/latest/docs/reference/config/networking/virtual-service/, the prefix-based match on "/" should work, not sure why and how the behaviour on istio is changed.