``utils``
=========

This module contains a number of utility functions used at PSI. It is the
PSI-specific analogue to Puppetlabs' ``stdlib``.


Functions
---------


``check_os``
~~~~~~~~~~~~

Accepts an arbitrary number of arguments, each of which is a string of the form
``$osfamily $majorversion`` as reported by ``facter(8)``. If the facts of the
client system **do not** match any of the arguments, the function aborts the
Puppet run.


``rand_time``
~~~~~~~~~~~~~

This function takes a parameter specifying a time window and returns a specific
time within this window based on the MD5 on the hostname. This allows scheduling
cron jobs etc uniformly across a fleet of system within a given window, while
keeping the time on each system predictable.

The format for the argument specifying the time window is ``HH:MM--HH:MM``. The
window must not include midnight.

The format of the return value is ``HH:MM``.