[Spacewalk-list] Re: Spacewalk/Cobbler templating features pending in Cobbler 1.3 == config management

[Michael DeHaan]

Michael DeHaan wrote:
> Hi folks,
>
> I know Cobbler/Spacewalk integration is ongoing so I wanted to bring 
> up a new Cobbler feature that may help with configuration management 
> as well as provisioning.  This is a new feature that has just been 
> suggested a few weeks ago but I think it's interesting -- primarily 
> because it's incredibly simple to do.
>
> Basically James Cammarata's pending patches to cobbler (posted to the 
> cobbler mailing list) allow us to use Cobbler's templating mechanism 
> to template arbitrary files (not just kickstarts and yum configs) 
> using Cheetah.    This would be usable as a future templating 
> mechanism for configuration files within Satellite, potentially 
> replacing Satellite config management without bringing in the problems 
> of managing a more complicated configuration management infrastructure.
>
> At the command line level, it looks like this:
>
> cobbler system edit --name=foo 
> --template-files="/srv/source.template=/etc/foo/bar 
> /srv/source2.template=/etc/baz/glurp"
>
> Basically this allows a hash of "source=destination" keypairs to be 
> applied anywhere throughout the cobbler "distro, profile, system" 
> object chain.  These templates can then be inherited between 
> distributions, profiles, and systems.   Any cobbler variables applied 
> to "--ksmeta" can then be evaluated through the template, and the 
> template can also contain any Cheetah directives of Cobbler snippets 
> (see cheetahtemplate.org/learn).
>
> In kickstart %post, a kickstart snippet translates these to a series 
> of simple wget's to suck down the files and install them on the 
> systems in the right locations.   This is all automatically built out 
> for the user so the provisioning stage automatically deploys the 
> template files:
>
> A logical extension of this is a call in koan to keep templates up to 
> date:
>
> koan --server=cobbler.example.org --system=foo.example.org --update-files
>
> This would pull down the files given in "--template-files" and 
> retemplate them dynamically.
>
> Essentially you get an ultra-lightweight configuration management 
> system for free for users who do not want to assume the complexity of 
> maintaining a Puppet and/or cfengine infrastructure, which can at 
> times feel very much like a development exercise.   (We also know of a 
> couple of major puppet problems presently -- (A) rpmdb corruption, and 
> (B) packaging each package install in a single yum transaction leading 
> to a long install time overhead.
>
> As I know we wanted to streamline Satellite's configuration 
> management, this may be an interesting proposal as it uses the same 
> tools as the install system and can manage both in parallel  If 
> someone wanted to use a heavier CMS on top of things, they still 
> could, though this would provide an option similar to what they have 
> now, with the additional ability to use the full power of Cheetah 
> inside their templates.
> Cobbler profiles then become the same concept for managing an existing 
> system as they do a "to-be-installed" system.
>
> Anyway, we still have to implement a bit before the above is feasible, 
> but I wanted to throw the idea out there so we could be thinking of 
> it.   It seems to be a very powerful idea and also something that 
> would be trivial to fit into a GUI.   I am a bit worried that while 
> puppet/cfengine/bcfg2 are awesomely powerful, putting them into a GUI 
> app for integration reasons does not really offer any advantages over 
> using them stock.   With the above, we could have a lightweight CM 
> system in the core Spacewalk app and still allow usage of those said 
> tools out of band as needed.  Should folks /do/ want to integrate with 
> Puppet or another CMS, they have tools like this  
> https://fedorahosted.org/cobbler/wiki/UsingCobblerWithConfigManagementSystem 
> that we could do to help them with this, but some "vi" is still required.
>
> --Michael
>
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Also described here:  
https://fedorahosted.org/cobbler/wiki/BuiltinConfigManagement