I have a website running on GCP Kubernetes. It uses an Ingress to receive traffic initially and is then passed down to a Deployment/Workload.
If for some reason the backend health check fails, we receive a generic 500 status page. I would like to serve a more stylish version of that page for consumers. Ideally we'd tune the system so this won't happen, but sometimes it still occurs.
No such feature exists as of now in the GCLB to do that. You can always use your own ingress controller like Nginx and set-up the following configuration:
error_page 500 502 503 504 /custom_50x.html;
location = /custom_50x.html {
root /usr/share/nginx/html;
internal;
}