[chef] nagios cookbook simplification

[Joshua Timberman < >]

Ohai Chefs,

You may have noticed that our Nagios cookbook has undergone some dramatic
changes on the master branch in GitHub. We have about 20 tickets that are
committed and awaiting a release.

Tim Smith, Paul Graydon, and Ben Hartshorne have done some excellent work
here, and we're working on getting it all tested and ready for release.
This does constitute a major version change, and this will all be
reflected in a version "4.0" (current is 3.1.0).

If you're not already doing so, we recommend pinning the version to one
that you have tested and works in your infrastructure.

One of the major changes is that all the built-in assumptions about what
to monitor are removed. This makes it easier for consumers of the cookbook
to create their own custom monitoring by managing service checks in data
bag items, rather than the cookbook's templates. This keeps the data
separate, and allows easier reuse and sharing. The nagios_nrpecheck LWRP
can also be used for NRPE-specific checks.

Another major change aims to simplify the code in the server recipe, and
make it easier to extend. There's now a helper library for performing the
data bag searches. We felt it was easier to read than worrying about all
the exception handling details that were cluttering the recipe.

We're currently testing the changes to ensure that the cookbook functions
as intended. The WIP for the next release is here:

* https://github.com/opscode-cookbooks/nagios/tree/jtimberman/v4

If you see Tim, Paul or Ben, give them a high-5 (or hugs!) for their work
in making this cookbook more library-like and easier to use. They're
usually hanging around IRC on #chef :-).

Cheers,
Joshua