Example script to deploy a Rails application via Git post-receive hook

post-receive-deploy.rb

#!/usr/bin/env ruby

# Example script to deploy a Rails application via Git post-receive hook
#
# INSTALL
#
# $ curl http://gist.github.com/442106.txt -o post-receive
# $ mv post-receive path/to/to/your/repo.git/hooks/post-receive
# $ chmod +x post-receive

INPUT = STDIN.read.strip
# puts INPUT.inspect # DEBUG

# === CONFIGURE THE SCRIPT HERE =================
deploy_branch    = 'deploy'
application_path = '/www/data/applications/myapp'
# ===============================================

old_revision,
new_revision,
branch = INPUT.split(' ')

if branch =~ Regexp.new(deploy_branch)

  DEPLOY_COMMAND =<<-END
  (
  unset GIT_DIR \
    && \
  cd #{application_path} \
    && \
  git fetch --quiet \
    && \
  git reset --hard -q origin/#{deploy_branch}
  )
  END

  RESTART_COMMAND =<<-END
  (
  touch #{application_path}/tmp/restart.txt
  )
  END

  puts "Updating application code..."
  system DEPLOY_COMMAND
  puts "Restarting application..."
  system RESTART_COMMAND
  
end