How can I keep a Passenger Standalone up even after a restart?

Question

I have a few apps running rails 3 on ruby 1.9.2 and deployed on a Ubuntu 10.04 LTS machine using nginx + passenger. Now, I need to add a new app that runs on ruby 1.8.7 (REE) and Rails 2. I accomplished to do that with RVM, Passenger Standalone and a reverse proxy.

The problem is that, every time I have to restart the server (to install security updates for example), I have to start Passenger Standalone manually.

Is there a way to start it automatically? I was told to use Monit or God, but I couldn't be able to write a proper recipe that works with Passenger Standalone. I also had a few problems with God and RVM, so if you have a solution that doesn't use God, or if you know how to configure God/Rvm properly, it's even better.

Answer 1

Here is what I got working. Using Upstart (Ubuntu 10.04) to start the passenger daemon

My environment uses rvm with ruby 1.9.2 and apache and my rails app is deployed via capistrano

# Upstart: /etc/init/service_name.conf
description "start passenger stand-alone"
author "Me <[email protected]>"

# Stanzas
#
# Stanzas control when and how a process is started and stopped
# See a list of stanzas here: http://upstart.ubuntu.com/wiki/Stanzas#respawn

# When to start the service
start on started mysql

# When to stop the service
stop on runlevel [016]

# Automatically restart process if crashed
respawn

# Essentially lets upstart know the process will detach itself to the background
expect fork

# Run before process
pre-start script
end script

# Start the process
script
        cd /var/path/to/app/staging/current
        sh HOME=/home/deploy /usr/local/rvm/gems/ruby-1.9.2-p136@appname/gems/passenger-3.0.7/bin/passenger start --user 'deploy' -p '5000' -a '127.0.0.1' -e 'production'
end script

and the apache config:

<VirtualHost *:80>
    ServerName myapp.com

    PassengerEnabled off

                <Proxy *>
                        Order deny,allow
                        Allow from all
                </Proxy>

    ProxyPass / http://127.0.0.1:5000/
    ProxyPassReverse / http://127.0.0.1:5000/

</VirtualHost>

Upstart doesn't set ENV['HOME'] which passenger relies on, so we have to pass that when executing the passenger command. Other than that its pretty straight forward.

A note for debugging: https://serverfault.com/questions/114052/logging-a-daemons-output-with-upstart (append something like >> /tmp/upstart.log 2>&1 to the second line in the script block)

Hope this helps.