log $proxy_host $proxy_port by lua

[saravsars]

Is it possible to log $proxy_host by lua ?
proxy_host is working fine in access log but prints nil while logging through lua.

[agentzh]

The $proxy_host variable is explicitly prohibiting dynamic reads from scripting languages (like Lua and Perl) when it is created in the standard ngx_http_proxy_module (by setting the NGX_HTTP_VAR_NOHASH flag for the Nginx variable on the C land). There's nothing I can do on the ngx_lua module side.

Maybe you should ask the official Nginx team (on the nginx-devel mailing list) to remove this flag for $proxy_host (and $proxy_port, maybe). You need to elaborate your use cases to convince them though :)

Good luck!

[agentzh]

@saravsars I've prepared a simple patch for the Nginx core to make $proxy_host and $proxy_port accessible for dynamic languages like Lua and Perl:

https://raw.github.com/agentzh/ngx_openresty/master/patches/nginx-1.4.3-proxy_host_port_vars.patch

Will you try this patch out on your side?

[agentzh]

@saravsars I've just submitted my patch to the nginx-devel mailing list:

http://mailman.nginx.org/pipermail/nginx-devel/2013-October/004440.html

Hopefully it will get merged into the mainline Nginx soon :)

[saravsars]

@agentzh great :)

I'll try this patch.

Thanks 👍

[agentzh]

Consider it resolved.