Ingress Default Backend doesn't know JSON

[BugRoger]

Implement a default backend for the nginx-ingress that speaks html and json. This is required for various clients to be able to detect and report an error.

[auhlig]

This might do the trick https://github.com/kubernetes/ingress-nginx/tree/master/images/custom-error-pages. Gets the format from the request and responds accordingly.

[auhlig]

Replaced by custom backend that knows JSON and HTTP. Backend will respond accordingly. Which errors are handled by the backend has to be configured in the ingress cm. Done this for 404, 500 errors. Can we close the issue?
EDIT: Currently rolled out to admin cluster. Do we want this everywhere?

[databus23]

We want this in all kubernikus control planes. Has this already happend? /cc @auhlig

[auhlig]

Just admin cluster for now. I'll roll this out to the other regions today and close this issue afterwards.