Hello!
On Sat, Oct 17, 2015 at 4:41 AM, Nicholas Pettas wrote:
> I'm in a situation where I need to return a certain http code depending on
> the body of a response coming from a reverse proxy. I'm using the
> redis2-nginx-module to retrieve cached responses.
> For example, I may store STATUS_403 in the response body and I'd like nginx
> to return a 403 http status.
You can use ngx.location.capture to initiate a subrequest to the
original location configured by ngx_proxy and etc, which returns the
fully buffered response body in a Lua string. Then you can easily test
the Lua string and perform ngx.exit(403) or just forward to the
client. And you can easily do caching on the Lua land as well (via the
nonblocking lua-resty-redis library, for example). See
https://github.com/openresty/lua-nginx-module#ngxlocationcapture
But be careful with VERY large response bodies. Your requirement
defeats the application of streaming processing and outputting since
your response header will not be able to sent before you buffer a
potentially large part of (or even all of) the response body, which
requires excessive buffering anyway, no matter what.
Regards,
-agentzh
