Cobbler DHCP config

I'm working on installing Cobbler so that I have a reliable way to automate the install of my linux systems.  Following my first post will get the software installed, so now I was ready to move on to actually getting a PXE boot to install from Cobbler.

Looked up the directions here, and the steps are pretty straight forward.  If you're continuing from my previous post, it would look something like this:

1. insert your dvd with the distro
2. yum -y install dhcp
3. mount /dev/dvd /media
4. cobbler import --path=/media --name=CentOS6 (this takes a while, press [CTRL+Z], then run bg [ENTER] to send it to the background)
5. vi /etc/cobbler/dhcp.template
6. edit per your network, mine looked like this:

subnet 10.1.2.0 netmask 255.255.255.0 {
     option routers             10.1.2.1;
     option domain-name-servers 68.87.85.102 68.87.69.150;
     option subnet-mask         255.255.255.0;
     range dynamic-bootp        10.1.2.100 10.1.2.254;
     filename                   "/pxelinux.0";
     default-lease-time         21600;
     max-lease-time             43200;
     next-server                10.1.2.26;
}

7. service cobblerd restart
8. cobbler sync

All is well, we're now ready to PXE boot clients, and Cobbler will..... what's this?

running: dhcpd -t -q
received on stdout:
received on stderr:
dhcpd -t failed
Exception occured: <class 'cobbler.cexceptions.CX'>
Exception value: 'cobbler trigger failed: cobbler.modules.sync_post_restart_services'
Exception Info:
  File "/usr/lib/python2.6/site-packages/cobbler/remote.py", line 89, in run
    rc = self._run(self)
   File "/usr/lib/python2.6/site-packages/cobbler/remote.py", line 184, in runner
    return self.remote.api.sync(self.options.get("verbose",False),logger=self.logger)
   File "/usr/lib/python2.6/site-packages/cobbler/api.py", line 701, in sync
    return sync.run()
   File "/usr/lib/python2.6/site-packages/cobbler/action_sync.py", line 155, in run
    utils.run_triggers(self.api, None, "/var/lib/cobbler/triggers/sync/post/*", logger=self.logger)
   File "/usr/lib/python2.6/site-packages/cobbler/utils.py", line 918, in run_triggers
    raise CX("cobbler trigger failed: %s" % m.__name__)

!!! TASK FAILED !!!

hmm.. well, we can see that there is an issue with dhcpd, lets try to start the service on it's own:

[root@OPS8-Cobbler ~]# service dhcpd start
Starting dhcpd:                                            [FAILED]
[root@OPS8-Cobbler ~]#

Here's the log from /var/log/messages while trying to start the service above:

Jul  2 17:38:48 OPS8-Cobbler dhcpd: Internet Systems Consortium DHCP Server 4.1.1-P1
Jul  2 17:38:48 OPS8-Cobbler dhcpd: Copyright 2004-2010 Internet Systems Consortium.
Jul  2 17:38:48 OPS8-Cobbler dhcpd: All rights reserved.
Jul  2 17:38:48 OPS8-Cobbler dhcpd: For info, please visit https://www.isc.org/software/dhcp/
Jul  2 17:38:48 OPS8-Cobbler dhcpd: /etc/dhcp/dhcpd.conf line 19: semicolon expected.
Jul  2 17:38:48 OPS8-Cobbler dhcpd:      option domain-name-servers 68.87.85.102 68.
Jul  2 17:38:48 OPS8-Cobbler dhcpd:                                                ^
Jul  2 17:38:48 OPS8-Cobbler dhcpd: Configuration file errors encountered -- exiting
Jul  2 17:38:48 OPS8-Cobbler dhcpd:

Looking at /etc/dhcp/dhcpd.conf, I realized that I'd left a comma out of the template config.  It should look like the following in /etc/cobbler/dhcp.template:

subnet 10.1.2.0 netmask 255.255.255.0 {
     option routers             10.1.2.1;
     option domain-name-servers 68.87.85.102, 68.87.69.150;
     option subnet-mask         255.255.255.0;
     range dynamic-bootp        10.1.2.100 10.1.2.254;
     filename                   "/pxelinux.0";
     default-lease-time         21600;
     max-lease-time             43200;
     next-server                10.1.2.26;
}

Now we restart the service and run a sync....

[root@OPS8-Cobbler ~]# service cobblerd restart

Stopping cobbler daemon:                                   [  OK  ]

Starting cobbler daemon:                                   [  OK  ]

[root@OPS8-Cobbler ~]# cobbler sync

task started: 2012-07-02_174015_sync

task started (id=Sync, time=Mon Jul  2 17:40:15 2012)

...

rendering DHCP files

generating /etc/dhcp/dhcpd.conf

...

running: dhcpd -t -q

received on stdout:

received on stderr:

running: service dhcpd restart

received on stdout: Starting dhcpd: [  OK  ]

...

*** TASK COMPLETE ***

[root@OPS8-Cobbler ~]#

much better.

A simple PXE test confirms that the service is working and providing addresses successfully.  However, I wasn't able to get the PXE menu to load on a network boot...  turns out that I didn't have the proper Firewall settings.  You can test by stopping your firewall (service iptables stop) and trying again; watch out for tcp/udp differences!!  After using the information under Firewall on this page  I was able to get the PXE boot menu to load and test the install.