I’m attempting to do the same thing, but I’m using Puma instead of Unicorn (not sure if that makes a difference). I’m also trying to have two subdomains (api and ui), as my main domain currently points to a different IP address while I stage these changes.

My file looks like this:

upstream puma {
  server unix:///home/rails/app-name/shared/tmp/sockets/app-name-puma.sock;
}

server {
  listen 80;
  server_name api api.appname.info;

  # Uses Capistrano's default settings
  root /home/rails/app-name/current/public;
  access_log /home/rails/app-name/current/log/nginx.access.log;
  error_log /home/rails/app-name/current/log/nginx.error.log info;

  location ^~ /assets/ {
    gzip_static on;
    expires max;
    add_header Cache-Control public;
  }

  try_files $uri/index.html $uri @puma;
  location @puma {
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header Host $http_host;
    proxy_redirect off;

    proxy_pass http://puma;
  }

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

server {
  listen 80 default_server;
  server_name ui.appname.info;

  root /var/www/html;

  # Add index.php to the list if you are using PHP
  index index.html index.htm index.nginx-debian.html;


  location / {
          # First attempt to serve request as file, then
          # as directory, then fall back to displaying a 404.
          try_files $uri $uri/ =404;
  }
}