nginx_confi.conf

upstream unicorn {
  server unix:/tmp/unicorn.foo.sock fail_timeout=0;
}

server {
  listen 80 default deferred;
  listen 443 ssl default;
  ssl_certificate /etc/ssl/certs/foo.crt;
  ssl_certificate_key /etc/ssl/private/foo.key;

  server_name foo;
  root /var/apps/foo/current/public;

  try_files $uri/system/maintenance.html $uri/index.html $uri @unicorn;

  location @unicorn {
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header Host $http_host;
    proxy_redirect off;
    proxy_pass http://unicorn;
  }

  error_page 502 503 /maintenance.html;
  error_page 500 504 /500.html;
  keepalive_timeout 5;
}