Can we customise the httpproxy object error - "no healthy upstream"

[karthikinala]

Hi Community,

Currently, we are using Contour v1.29.1 with an HTTPProxy object to route our traffic. When a pod is restarting or down, the browser shows the default "no healthy upstream" error. We would like to replace this with a custom error message or banner. Is there a way to achieve this?

[mg1986jp]

Contour doesn't have a built-in way to customize the "no healthy upstream" error page since that response comes from Envoy itself when all backend pods are unhealthy or gone.

A couple of approaches though:

1. Use an Envoy local_reply config to override error responses. In Contour, you can set this through ContourConfiguration or the Contour config file:

envoy:
  listener:
    localReplyConfig:
      mappers:
        - filter:
            statusCodeFilter:
              comparison:
                op: EQ
                value:
                  defaultValue: 503
          body:
            inlineString: "Service temporarily unavailable. Please try again later."

2. Or set up a custom default backend service that handles 503s. You can configure a fallback service in your HTTPProxy that catches requests when the primary backend is down.

The first approach gives you more control over the response body/headers without needing an extra service.