[Question] How to modify the response body after kong.response.exit(in access phase)?

[luozhouyang]

Hi guys, I found that I can not modify the response body in a post-function plugin if kong.response.exit in access phase. What I want is to modify the response body when key-auth failed. Do you have any ideas?

[StarlightIbuki]

The API is designed so that the response cannot be overwritten. A possible workaround is to proxy the same route twice (an extra route to the proxy port) and change the response in the downstream proxy.

[luozhouyang]

SOLVED! I write a custom plugin to modify the response body. Here is the key steps:

• Drop the Content-Length header in header_filter phase
• Set the new body in body_filter phase

Here is an example:

function _M:header_filter(conf)
    kong.response.clear_header("Content-Length")
end

function _M:body_filter(conf)
    -- replace the body here
    local new_body = ...
    return kong.response.set_raw_body(new_body)
end