Re: Strategy for "one-off" tasks

[Jamie Wilkinson]

This one time, at band camp, David Douthitt wrote:
>Controlled update roll-outs are making this more of a necessity.  THe 
>idea is that I can update certain machines now, more machines one week 
>later, and more machines the week after that, until all are done.  This 
>is related to a one-time-only task in that this sort of thing would 
>only be done periodically.

Controlled rollouts can be done with selective classes.

groups:

    stage1 = ( foo bar baz )
    stage2 = ( quux )
    stage3 = ( some other machines )

    rollout = ( stage1 stage2 )

editfiles:

    rollout::

        ...


You just add the machines that you want rolled to the class as you go along.

>Installs also come to mind.  There are certain things I don't want done 
>all the time that are only done during an installation.  If the 
>installation requirements change (that is, a new utility needs to be 
>installed) then I would want to install that utility once only 
>throughout the enterprise.

I think you're missing the point of convergence.  It's not a "one-off", it's
"does this need to happen, or doesn't it?".

Test if the new utility isn't installed, and then install it.  It's a
"one-off" as long as far as you're concerned, because cfengine is converging
on the wanted configuration of your system.


-- 
jaq@spacepants.org                           http://spacepants.org/jaq.gpg