[Dnsmasq-discuss] Ideas for handing out "per blade" information

Paul Smith psmith at gnu.org
Wed Oct 21 22:26:06 BST 2009

Hi all.

I have an environment with lots of blades (on the order of 150-200 or
so), all getting IP information from a central server using dnsmasq as
the DHCP server.

What I need to do is provide some information to each blade when it
registers, and (some of) this information will be specific to a given
blade (said another way, it will be different for each blade).  I was
hoping to use the DHCP response to supply this information, rather than
invent some new protocol of my own, create a daemon, etc. etc.

On the server I actually already know the MAC addresses that the blades
will register with, so I was going to use that as a key to look up the
per-blade information when the DHCP request is received.

Also, ideally the information would be obtained by running a script with
the MAC address as the argument, since these addresses can change during
the runtime of the system (someone can pull a blade and put a new one,
with a different MAC, in, for example, or they could even swap two
blades which means the information I want give them will change, since
some of it is position-dependent) and I'd prefer to grab these
dynamically rather than having some kind of timeout etc.  But, if that's
not possible I can work with it.

I've been looking through the dnsmasq man page and there are a lot of
options, but I'm not sure how to use them to do what I want.

The only mapping it appears that I can do based on MAC is dhcp-host
(maybe creating a file and giving it with dhcp-hostsfile).  But the only
way I can set options, that I can see, is using dhcp-option which is
based on network-id.  There is no way to set the network-id based on the
MAC etc. that I can see.  There doesn't seem to be any way to give
specific options for a specific client.

Soooo... anyone have any ideas for me?


 Paul D. Smith <psmith at gnu.org>          Find some GNU make tips at:
 http://www.gnu.org                      http://make.mad-scientist.net
 "Please remain calm...I may be mad, but I am a professional." --Mad Scientist

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