multiple rails apps on nginx and unicorn

Question

I successfully setup a rails site using the Screencast 335 deploy to a VPS tutorial. Now I want to add another rails app on a new domain but I am confused about the steps required.

In the above setup, there are no changes to sites-available or /etc/nginx/nginx.conf. The only configuration is in unicorn.rb, unicorn_init.sh and nginx.conf in my apps config directory. The nginx.conf file looks like this:-

upstream unicorn {
  server unix:/tmp/unicorn.my_app.sock fail_timeout=0;
}
server {
  listen 80 default deferred;
  # server_name my_app.com.au www.my_app.com.au;
  root /var/www/my_app/current/public;
  location ^~ /assets/ {
    gzip_static on;
    expires max;
    add_header Cache-Control public;
  }
  try_files $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 500 502 503 504 /500.html;
  client_max_body_size 4G;
  keepalive_timeout 10;
}

In my Capistrano recipe I have this line

sudo "ln -nfs #{current_path}/config/nginx.conf /etc/nginx/sites-enabled/#{application}"

Is adding a second domain merely a matter of removing default deferred after listen and un-commenting the server_name section then repeating this config file with a different upstream socket name and server name for the second app? Will that work or do I need to transfer this file to sites-available and create a symbolic link to sites-enabled?

Answer 1

In unicorn.rb:

application 1:

root = "/var/www/application_1/current"
working_directory root
pid "#{root}/tmp/pids/unicorn-app1.pid"
listen "/tmp/unicorn.app1.sock"

application 2:

root = "/var/www/application_2/current"
working_directory root
pid "#{root}/tmp/pids/unicorn-app2.pid"
listen "/tmp/unicorn.app2.sock"

In nginx.conf:

application 1:

upstream app1_server {
  server unix:/tmp/unicorn.app1.sock fail_timeout=0;
}

server {
  listen 80;
  server_name my_app_1.com www.my_app_1.com;
  root /var/www/app1/current/public;

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

  try_files $uri/index.html $uri @app1_server;
  location @app1_server {
  proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
  proxy_set_header Host $http_host;
  proxy_redirect off;
  proxy_pass http://app1_server;
 }

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

application 2:

upstream app2_server {
  # point to app2 sock
  server unix:/tmp/unicorn.app2.sock fail_timeout=0;
}

server {
  listen 80;
  server_name my_app_2.com www.my_app_2.com;
  root /var/www/app2/current/public;

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

  try_files $uri/index.html $uri @app2_server;
  location @app2_server {
  proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
  proxy_set_header Host $http_host;
  proxy_redirect off;
  proxy_pass http://app2_server;
 }

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

Answer 2

It is really easy to host different apps on one host with Nginx and Unicorn.

The separation you can get by defining different names of the socket files of each application. Of course you should point the right current/public directories in the server section of nginx.conf.

The last touch is in the unicorn_init.sh file: on the top of it you should change APP_ROOT with the full path to current/public directory of your application.

If your setup is similar to the RailsCast's one, all the other things are done by capistrano .