How to reference OS Environment Variales in nginx.conf

[agentzh]

On Fri, Sep 16, 2011 at 5:03 AM, caoxingk <nginx-forum at nginx.us> wrote:
> After set a variable by `set $name value`, i can reference it like
> `$name`,
> but when i export a OS Environment Variale by `env name_from_env`, like
> http://wiki.nginx.org/CoreModule#env said,
> and i am sure the name_from_env is valid which defined form nginx's
> parent process.
>
> But, my friends, how to reference it ?

You can read system environment variables with ngx_lua enabled in your
nginx build: http://wiki.nginx.org/HttpLuaModule

    env PATH;
    http {
        ...
        server {
            location /path {
                set_by_lua $path 'return os.getenv("PATH")';
                ...
            }
        }

BTW, to use the set_by_lua directive, you also need to enable the
ngx_devel_kit module here: https://github.com/simpl/ngx_devel_kit
(it'll be easier if you use the ngx_openresty bundle).

Regards,
-agentzh