Not sure if I brought this up directly before, but this was linked in the highscalability.com article:
https://github.com/mpdehaan/ansible-examples
It definitely would require adjustment for your environment as the Ganglia config files are NOT simple.
This is a pretty good example of using includes to manage playbook structure though:
https://github.com/mpdehaan/ansible-examples/blob/master/monitoring.yml
https://github.com/mpdehaan/ansible-examples/blob/master/tasks/common.yml
https://github.com/mpdehaan/ansible-examples/blob/master/tasks/monitored_server.yml
https://github.com/mpdehaan/ansible-examples/blob/master/tasks/monitoring_server.yml
At the time this was written Ansible still used client-side templates, so the Jinja2 install step can be removed.
–Michael