Nginx variables similar to SetEnv in Apache?

Question

I use SetEnv in Apache to set some variables in virtualhosts that I recover in PHP using $_SERVER[the_variable].

Now I am switching to Perl Catalyst and

Answer 1

location / {
...
   fastcgi_param   APPLICATION_ENV  production;
   fastcgi_param   APPLICATION_CONFIG user;
...
}

but it's for PHP-CGI