Start SASS/Compass on Vagrant reload

I use SASS & Compass on most of my projects, as well as Vagrant. I normally have my puppet provisioning scripts start a compass watcher to compile my SASS files into CSS, but this no longer works with Vagrant 1.3.0+ as provision scripts aren’t run on vagrant up or vagrant reload (only on the first vagrant up). If you reload your VM, the compass watcher won’t be running.

It turned out to be pretty tricky to fix. Running a script at start-up isn’t that difficult, but the Vagrant shared folders won’t be mounted at that point, so Compass will exit. Luckily Vagrant has an Upstart event called vagrant-mounted that is fired once the shared folders have been mounted (this hook doesn’t seem to be documented).

I created an Upstart job (my VMs run on Ubuntu), /etc/init/compass.conf that looks like this:

# Compass Watch Service
description "Compass Watcher"
author "Brandon Wamboldt <[email protected]>"
start on vagrant-mounted
exec /usr/local/bin/compass watch --poll /var/www/html/projectname > /tmp/compass.log 2>&1
respawn
respawn limit 15 5

And that’s it. My Puppet manifest looks like this:

# Start Compass watching for changes to SASS files so we can compile to CSS
file { '/etc/init/compass.conf':
  ensure => 'file',
  source => '/vagrant/vagrant/puppet/init/compass.conf',
  owner => 'root',
  group => 'root',
}

service { 'compass':
  ensure => 'running',
  enable => true,
  require => File['/etc/init/compass.conf'],
}

It took a while to figure this out, so hopefully I can save someone else the trouble.