Custom Error Webpage for Avi-Generated Responses

This article describes how one can generate one’s own custom error page, with application-specific content.

Background

Currently, Avi Vantage can generate custom responses from policy, DataScript, or a POOL_DOWN action. Other than this, there are cases where we are unable to communicate with a back-end server (for instance 502), where we respond back to the client with a hard-coded page (non-custom). Customers occasionally prefer to generate their own custom error page, so that it doesn’t have “Avi” on the page, but rather some application-specific message.

How it Works

With Avi Vantage 17.1.3, a new DataScript event named RESP_FAILED is supported. It triggers when any error/timeout happens up to the point that a valid response header is received from the server and forwarded to client. For instance:

  • TCP/SSL connect/handshake to server fails
  • Request proxy/send to server times out
  • No response or partial response headers or bad response headers from the server
  • Server resets connection while the Avi SE is waiting for the server to respond

A DataScript attached to the RESP_FAILED event is executed. Example functions exposed to the script are avi.http.response(), avi.http.redirect(), and (the newly created) avi.http.internal_status(). The user can use these to customize response for the different types of failures, log the reason in Avi Logs, etc. Refer to the below Knowledge Base articles:

Updated: 2018-01-20 12:43:13 +0000