/usr/lib/one/onegate/config.ru is in opennebula-gate 4.12.3+dfsg-3build1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 | # If you are using self contained installation set this variable to the
# install location
#ENV['ONE_LOCATION']='/path/to/OpenNebula/install'
$: << '.'
require 'onegate-server'
run Sinatra::Application
|