nginx config with unicorn

nginx_site.conf

upstream rails_app_upstream {
  server unix:/home/deployer/projects/rails_app/shared/tmp/sockets/unicorn.socket fail_timeout=0;
}

server {
  #listen   80; ## listen for ipv4; this line is default and implied
  #listen   [::]:80 default ipv6only=on; ## listen for ipv6
  server_name localhost my_server.ru;

  root /home/deployer/projects/rails_app/current/public;
  index index.html index.htm;
  access_log /home/deployer/projects/rails_app/shared/log/nginx-access.log;
  error_log /home/deployer/projects/rails_app/shared/log/nginx-error.log;

  client_max_body_size       10m;
  client_body_buffer_size    128k;

  location / {
    try_files $uri/index.html $uri.html $uri @rails_app;
  }

  location @rails_app{
    proxy_pass http://rails_app_upstream;
    proxy_redirect     off;

    proxy_set_header   Host             $host;
    proxy_set_header   X-Real-IP        $remote_addr;
    proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for;

    proxy_connect_timeout      90;
    proxy_send_timeout         90;
    proxy_read_timeout         90;

    proxy_buffer_size          4k;
    proxy_buffers              4 32k;
    proxy_busy_buffers_size    64k;
    proxy_temp_file_write_size 64k;
  }

  location ~* ".*?\.(ico|css|js|gif|jpg|jpeg|png|doc|pdf)(\?[0-9]*)?$" {
    expires 24h;
    #expires max;
    proxy_cache_valid  200 302  60m;
    proxy_cache_valid  404      1m;
    break;
  }

}