Cloud 66

Custom web servers

Run your Rack apps with Passenger, Puma, Unicorn or Thin


About custom web servers

By default, stacks deployed by Cloud 66 run on Phusion Passenger behind Nginx. You can also choose to use one of several servers:


Custom web servers currently only apply to Rack-based stacks, not Docker stacks.


You need to choose your web server at the time of initial build of the stack. Changes to or from Passenger will not be applied after your stack has initially been built. You can however change freely between other supported servers after build.

Configurations for your Rack server

If you would like to use a different server, there are some points you’d need to consider for it to work with a Cloud 66 stack. These conventions will allow Cloud 66 to redirect traffic to your servers and manage them for availability, memory consumption and restart cycles.

Traffic Socket

For the traffic to be redirected to your web server, it should use a Unix socket at /tmp/web_server.sock

PID file

For the web server to be managed and restarted properly by Cloud 66, it needs to have it’s PID file at /tmp/

Manual control of the web servers

To control your web servers manually you can use the following commands:

Stop the web server

sudo bluepill cloud66_web_server stop

Start the web server

sudo bluepill cloud66_web_server quit
sudo bluepill load /etc/bluepill/autoload/cloud66_web_server.pill

Restart the web server

If supported by your web server, you can use the following command to restart the web server with no down time (this will send a USR2 signal to your webserver)

sudo bluepill cloud66_web_server restart