Write the description below

We are getting periodical out of space errors on tools-prometheus-03 (~1/week, unless it gets restarted, that also
happens relatively often).

One possible solution is to specify the retention by the available space instead of a time period, that means using the
option --storage.tsdb.retention.size.

This task is to:

• parametrize the puppet classes and template needed to use that new flag
• configure tools-prometheus-03 to use that flag instead

Helper dashboard: https://grafana-labs.wikimedia.org/goto/52qHqyXGk