Question

I would like to remap the 502 and 504 errors generated by Nginx when it can’t talk to the proxy successfully into 408 errors.

To be clear, when Nginx returns 502/504 and no body, it should instead return 408 and still no body.

I tried adding this directive, but it apparently corrupts the response headers:

error_page              502 =408;
error_page              504 =408;

Any idea how to do remap an Nginx error code?

Answer 1

http://nginx.org/r/error_page

syntax: error_page code … [=[response]] uri;

You forgot to specify the uri parameter (your =408 argument has been interpreted as a uri).

upd:

location / {
    error_page 502 504 =408 @empty;
}

location @empty {
    return 200 '';
}