Puppetry and replication [Was: email alias issue]

[Oleg Goldshmidt]

On Wed, Jul 20, 2011 at 5:26 AM, Amos Shapira <amos.shapira at gmail.com> wrote:

> That's exactly what we do (/etc/puppet on the *puppetmaster* is pushed
> out from subversion), and I say it's far better than having the entire
> /etc or any other sub-directory of the *puppet client* in SVN, which
> is the suggestion I responded to.

This is an interesting discussion even if it is not related to the
original topic of the thread.

When you say something is "better" or "worse" you would be prudent to
specify for what purpose.

1. I do not administer a large installation professionally - I wrote I
was using version control (I didn't mention SVN specifically) and I
was thinking of my personal setup. Puppet is hardly worth the overhead
if all you do is 2-3 computers, probably different in many respects.

2. At work we have a fairly significant number of systems (R&D,
integration, QA, etc, like you describe). We still have a lot more
Windows than Linux, and our Linux administration is not terribly
sophisticated (I am not the admin :). What we do though is VMware
everywhere, and we clone VMs rather than cloning configuration a la
puppet - works for Windows and Linux alike, of course.

Hetz, AFAIK, does administer a business, but I have a suspicion that
he uses VMs as well - ?

3. In a large scale datacenter there is a (rarely used, I think) third
option of cloning entire disks on the storage side of things and
provisioning systems that way. One advantage is that you can do all
that is needed before you actually boot for the first time, which
neither version control nor puppet allow (VM cloning is similar in
this respect). Another advantage, of course, is that there is no
installation. It's similar to puppet in the sense that there is a
master and replicas, but at a different level of granularity.

I don't have enough experience with puppet, so if anyone pitches in
with a serious analysis of pros and cons of full system replication vs
puppet (general consideration, interesting use cases, etc.) I'd be
interested to listen.

-- 
Oleg Goldshmidt | pub at goldshmidt.org