The problem with lua and x-accel-redirect

antonp1976 · 2012-12-27T03:26:27+00:00

Hello! On Mon, Dec 24, 2012 at 5:36 PM, senthil wrote: > I have built a openresty app with redis as backend > > I got my basic app working on hero...

The problem with lua and x-accel-redirect

antonp1976

Hello. I have next problem.

Here is my location for download in nginx

location /test {

lua_code_cache off;

content_by_lua_file download.lua;

}

Contents of donwload.lua file:

local lfs = require "lfs"

local file_path = '/home/front/public_html/storage/0000000011';

ngx.header["Content-Type"] = 'application/octet-stream';

ngx.header["Content-Disposition"] = 'attachment; filename="111a"';

ngx.header["Content-Length"] = lfs.attributes(file_path,"size");

ngx.header["X-Accel-Redirect"] = '/storage/0000000011';

if ngx.var.limit_rate then ngx.header["X-Accel-Limit-Rate"] = ngx.var.limit_rate;

end

The location "storage"

location ^~ /storage/ { root /home/front/public_html/; internal; }

But after i tried to download by accessing /test/ location. it asks me to save the file but download doesn't starts.

Here is a headers from lynx

HTTP/1.1 200 OK Server: nginx Date: Wed, 26 Dec 2012 19:25:53 GMT Content-Type: application/octet-stream Connection: close Content-Disposition: attachment; filename="111a" Content-Length: 18195 X-Accel-Redirect: /storage/0000000011 X-Accel-Limit-Rate: 51200

What i'm doing wrong ? Please help me.

agentzh

Hello!

On Wed, Dec 26, 2012 at 11:26 AM,  antonp1976 wrote:
>
> What i'm doing wrong ? Please help me.
>

Yes, you're doing wrong here. The response header "X-Accel-Redirect"
is only recognized and processed by those nginx upstream modules like
ngx_proxy, ngx_fastcgi and ngx_uwsgi.

I think you need to use ngx.exec to perform explicit internal redirects instead:

    http://wiki.nginx.org/HttpLuaModule#ngx.exec

Or just use rewrite_by_lua (and ngx.req.set_uri, optionally).

Best regards,
-agentzh

antonp1976

Thanks a lot, done it with rewrite_by_lua.

One more question, i've try to get a var from my memc daemon using lua
to restrict number of connections (by limit_conn directive)

But when i try to use
if ($limip = 1) { limit_conn lim_ip 1; }

I've dot an error:
"limit_conn" directive is not allowed here in

as wrote in the documentation limit_conn not allowed to use in the "if"
block, only for the whole location.
Is there any way ti pass it ?

I need to dynamicaly configure this value for ONE location.



27.12.12, 8:03, agentzh пишет:
> Hello!
>
> On Wed, Dec 26, 2012 at 11:26 AM,  antonp1976 wrote:
>> What i'm doing wrong ? Please help me.
>>
> Yes, you're doing wrong here. The response header "X-Accel-Redirect"
> is only recognized and processed by those nginx upstream modules like
> ngx_proxy, ngx_fastcgi and ngx_uwsgi.
>
> I think you need to use ngx.exec to perform explicit internal redirects instead:
>
>     http://wiki.nginx.org/HttpLuaModule#ngx.exec
>
> Or just use rewrite_by_lua (and ngx.req.set_uri, optionally).
>
> Best regards,
> -agentzh
>

agentzh

Hello!

On Thu, Dec 27, 2012 at 12:35 AM, Anton Petin wrote:
> But when i try to use
> if ($limip = 1) { limit_conn lim_ip 1; }
>
> I've dot an error:
> "limit_conn" directive is not allowed here in
>
> as wrote in the documentation limit_conn not allowed to use in the "if"
> block, only for the whole location.
> Is there any way ti pass it ?
>
> I need to dynamicaly configure this value for ONE location.
>

You'll have to use separate locations for different limit_conn
configurations. You can use internal redirects to dispatch to
different named locations (configured by limit_conn) in your entry
location.

Two more elegant (but harder) approaches may be

1. patch ngx_limit_conn to make limit_conn support Nginx variables; or
2. reimplement the functionality of limit_conn in Lua via the
ngx.shared.DICT API.

Best regards,
-agentzh