I’ve been setting monit up to keep an eye on the various parts associated with a Rails app (2.3.x but patched to use Bundler for gem management) and ran into a problem getting my Gemfile recognised properly.
The essential piece I’d missed was the BUNDLE_GEMFILE environment variable. So for, say, delayed_job what was needed was:
start program = "/usr/bin/env RAILS_ENV=production \ BUNDLE_GEMFILE=/var/www/my_app/current/Gemfile \ PATH=/opt/ruby/bin:$PATH \ /var/www/my_app/current/script/delayed_job start"
Hopefully that’ll save someone a few minutes.