[et-mgmt-tools] Re: Two cobbler feature suggestions (fwd)

Bryan K. Wright bryan at ayesha.phys.virginia.edu
Mon May 7 12:51:33 UTC 2007

Hi folks,

	Here's a note I sent recently to Michael DeHaan, and his response.
He suggested I forward it to the list.  As he suggests, I'll take a look
at Cobbler's trigger infrastructure and see what would be required
to get Cobbler to play with dnsmasq.

						Bryan Wright
------- Forwarded Message

Date: Mon, 07 May 2007 08:15:51 -0400
From: Michael DeHaan <mdehaan at redhat.com>
User-Agent: Thunderbird (Macintosh/20070221)
MIME-Version: 1.0
To: bryan at Virginia.EDU

Bryan K. Wright wrote:


> Hi Michael,
> 	Thanks for writing cobbler! I've been using it for a little
> while now, and I'm loving it.

Glad you like it and thanks for the suggestions.   Quick question -- Can 
this email be sent to et-mgmt-tools at redhat.com?     Other folks might 
benefit from this discussion...

> 	For what it's worth, here are a couple of feature suggestions
> for future versions:
> 1.  It would be nice to have a flag like "--pxe-name" when adding
>     systems.  I'd like to be able to assign names to the hosts in
>     the dhcpd.conf, instead of the default "label1", "label2", etc.
Agreed.   I was having this discussion yesterday on IRC (#cobbler / 
> 2.  This would be a lot of work, but have you thought about supporting
>     dnsmasq as an alternative to the ISC dhcpd?  Dnsmasq is nice since
>     it can draw its dhcpd information directly from /etc/hosts and
>     /etc/ethers, and it has a cacheing DNS built in.  Right now,
>     I'm using cobbler for provisioning via dhcp/pxe, and maintaining 
>     /etc/hosts by hand and running dnsmasq to serve up hostname resolution 
>     from it (with dnsmasq's dhcp service turned off).  It'd be great
>     to get rid of the duplication.

It's doable, although I am not super-familiar with dnsmasq.    A couple 
of options:

(1)  You turn off manage_dhcp in /var/lib/cobbler/settings, and use the 
trigger script infrastructure (think "plugins", they're mentioned in 
the  manpage) and write a quick extension using the cobbler API to 
update dnsmasq when new cobbler systems are added/removed.     Trigger 
scripts are just executable scripts in /var/lib/cobbler/triggers that 
get called with the name of the object being added.   If written in 
Python, using the cobbler API to mine the rest of the system info (such 
as the value for a --pxe-name parameter) is fairly easy.

(2)  You can submit a patch to cobbler's api_sync mode, to accept both 
modes of dealing with dhcp.   I would probably have to tweak it just a 
little bit, but that would be a great start.  Ideally the choice of 
servers would be in /var/lib/cobbler/settings, to switch between approaches.

(3)  You can send me an example script of how you are configuring 
dnsmasq today, and I can possibly incorporate something similar into 

Some other folks are exploring dynamic DNS integration and possible 
tie-ins with omshell/OMAPI but I think this could be more interesting.   
I would like to do some exploration myself and see where this goes.   
Generally this looks like it would be best
implemented as a trigger, and someone could choose whether or not to 
install it -- possibly something that could be shipped in a "contrib" 

If you'd like to forward this to et-mgmt-tools at redhat.com that would be 
great -- I'm sure other users have input on this as well.


> 						Bryan

------- End of Forwarded Message

Bryan Wright              |"If you take cranberries and stew them like 
Physics Department        | applesauce, they taste much more like prunes
University of Virginia    | than rhubarb does."  --  Groucho 
Charlottesville, VA  22901|			
(434) 924-7218            |         bryan at virginia.edu

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