为rails app + unicorn + nginx设置多个根

Question

在使用带有rails应用程序的unicorn + nginx时，我需要帮助在同一服务器中设置一些根。

当我只设置根时，我的应用程序可以正常工作。

upstream contab_teste {
    server unix:/home/ubuntu/apps/contab/shared/sockets/unicorn.sock fail_timeout=0;
}

server {
  listen 80;
  server_name default_server;
  rails_env production;
  try_files $uri $uri/index.html @app;
  root /home/ubuntu/apps/contab/public;
  location @app {
      proxy_pass http://contab_teste;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header Host $http_host;
      proxy_redirect off;
  }

  error_page 500 502 503 504 /500.html;
  client_max_body_size 4G;
  keepalive_timeout 10;
}

当我设置另一个根目录时，它不起作用。 我尝试过某种方式这样做：

upstream contab_teste {
    server unix:/home/ubuntu/apps/contab/shared/sockets/unicorn.sock fail_timeout=0;
}

upstream contab_apresentacao {
    server unix:/home/ubuntu/apps/contab_apresentacao/shared/sockets/unicorn.sock fail_timeout=0;
}

server {
  listen 80;
  server_name default_server;
  rails_env production;
  try_files $uri $uri/index.html @app;
  root /home/ubuntu/apps/contab/public;
  location @app {
      proxy_pass http://contab_teste;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header Host $http_host;
      proxy_redirect off;
  }

  location /apresentacao {
      #rewrite ^/apresentacao(.*) /$1 break;
      root /home/ubuntu/apps/contab_apresentacao/public;
      proxy_pass http://contab_apresentacao;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header Host $http_host;
      proxy_redirect off;
  }
  error_page 500 502 503 504 /500.html;
  client_max_body_size 4G;
  keepalive_timeout 10;
}

有人可以帮我吗？ 谢谢！