Overrides and node classification (was: Template Nodes considered harmful)

I'm going somewhat off-topic here, but there are some choices I have to
make here and I'm interested in opinions for how people are laying out
their overrides.

On 24 October 2007 19:38, Digant C Kasundra [digant@xxxxxxxxxxxx] wrote:

>> Right.  I meant that a class would inherit webserver and modify it or
you could just
>> include the class in the node if it was fine as is.  I think we're on
the same page on this.

This is exactly what we're doing.  We also use a simple external node
classifier to define *all* class memberships.  A host gets nothing
unless there is say-so from the classifier.

The tricky bit is if I want a server which is customised so the "ntp"
class is overridden for example.  You can't override a resource defined
in a class unless in a parent class (ref:
http://reductivelabs.com/trac/puppet/wiki/LanguageTutorial) - so I have
to ditch the ntp class from my classification list and include a new
class ntp_custom which inherits ntp.

All well and good, but I used to have a 'base' class set by the
classifier which is a simple include of 20 or so classes!  Hard to
override if you've already included it.  My solution was to have a
'standard' class group defined entirely within the classifier which
pumps out this list of 20 or so when called.  It has the cleverness to
do "no-include class" functionality - outside of Puppet.  Then you
include the ntp_custom class.

Outside of Puppet - precisely I hear you say.  The classifier is down to
local conventions, etc.  However, I'm keen to hear the way other people
have done this or any critique of the above approach.

Cheers,
Derek
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