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PXE boot-howto-simplified:
= Scenario =


storage.homedomain.com 	: Install server
kvm.homedomain.com	: Physical host to host kvm virtual machines. Will be used as test server to be installed using PXE from the install server.
xen.homedomain.com	: Physical host to host xen virtual machines. Will be used as test server to be installed using PXE from the install server.


The install server (storage):
----------------------------

Copy the (expanded) CentOS-5.4-x86_64 DVD in a directory /data/cdimages/CentOS-5.4-x86_64 .


Import the gpg key. It would be wise to do it at this moment:

<pre>
rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5
</pre>


Create a local repository for this server, so it can install any required packages , even if it is not connected to internet.

<pre>
[root@storage ~]# vi /etc/yum.repos.d/CentOS-localmedia.repo
[CentOS-5.4-x86_64-local]
name=RedHat Enterprise Linux $releasever - $basearch
baseurl=file:///data/cdimages/CentOS-5.4-x86_64/
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release
[root@storage ~]#
</pre>

You can verify the new repository using:

<pre>
[root@storage ~]# yum repolist
Loaded plugins: fastestmirror
Determining fastest mirrors
CentOS-5.4-x86_64-local                                                                     | 2.1 kB     00:00
CentOS-5.4-x86_64-local/primary_db                                                          | 2.0 MB     00:00
repo id                                     repo name                                               status
CentOS-5.4-x86_64-local                      RedHat Enterprise Linux 5 - x86_64                      enabled: 3,348
repolist: 3,348
[root@storage ~]#
</pre>

You must verify it using the following method too:-

<pre>
[root@storage ~]# yum list | tail
yum-protect-packages.noarch          1.1.16-13.el5.centos CentOS-5.4-x86_64-local
yum-protectbase.noarch               1.1.16-13.el5.centos CentOS-5.4-x86_64-local
yum-security.noarch                  1.1.16-13.el5.centos CentOS-5.4-x86_64-local
yum-tmprepo.noarch                   1.1.16-13.el5.centos CentOS-5.4-x86_64-local
yum-updateonboot.noarch              1.1.16-13.el5.centos CentOS-5.4-x86_64-local
yum-utils.noarch                     1.1.16-13.el5.centos CentOS-5.4-x86_64-local
yum-verify.noarch                    1.1.16-13.el5.centos CentOS-5.4-x86_64-local
yum-versionlock.noarch               1.1.16-13.el5.centos CentOS-5.4-x86_64-local
zenity.x86_64                        2.16.0-2.el5         CentOS-5.4-x86_64-local
zsh-html.x86_64                      4.2.6-3.el5          CentOS-5.4-x86_64-local
[root@storage ~]#
</pre>

This shows that the repository and it's packages is being correctly loaded / listed.
	

You need to have the following installed on the install server:

* dhcp (server)
* syslinux
* tfpt
* httpd


<pre>
[root@storage ~]# yum -y install httpd tftp-server syslinux dhcp
</pre>

Now create an httpd alias , which will be used by the machines being installed, to pull pakcages from httpd repository.

<pre>
vi /etc/httpd/conf.d/CentOS-5.4-x86_64.conf

Alias /CentOS-5.4-x86_64 /data/cdimages/CentOS-5.4-x86_64/
<Location /CentOS-5.4-x86_64>
    Order deny,allow
    Allow from all
    Options +Indexes
</Location>
</pre>

The "Options +Indexes" seems to be un-necessary, but it is better to put it here. This will help you later to download individual packages from this local repository in difficult situations.


Restart Apache server:

service httpd restart

And check through a browser, if you are able to view the web page of your repository.


If you don't have a web browser available to you, try using a simple wget to pull index.html from this link.

<pre>
[root@storage ~]# wget http://192.168.1.100/CentOS-5.4-x86_64/
--2010-02-05 11:41:11--  http://192.168.1.100/CentOS-5.4-x86_64/
Connecting to 192.168.1.100:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 6623 (6.5K) [text/html]
Saving to: `index.html'

100%[========================================================================>] 6,623       --.-K/s   in 0s

2010-02-05 11:41:11 (134 MB/s) - `index.html' saved [6623/6623]

[root@storage ~]#
</pre>


Time to setup dhcp service on this (install) server:

<pre>
# vi /etc/dhcpd.conf
ddns-update-style interim;
ignore client-updates;


subnet 192.168.1.0 netmask 255.255.255.0 {

# --- default gateway
        option routers                  192.168.1.1;
        option subnet-mask              255.255.255.0;
        option domain-name              "homedomain.com";
        filename "pxelinux.0";
        range dynamic-bootp 192.168.1.11 192.168.1.20;
        default-lease-time 21600;
        max-lease-time 43200;
        next-server 192.168.1.100;

}
</pre>

Start the dhcpd service. Make sure that there is no other DHCP service running elsewhere on your network.

<pre>
service dhcpd restart
</pre>


Now it is time to setup the TFTP service:-

<pre>
[root@storage ~]# cat /etc/xinetd.d/tftp
service tftp
{
        socket_type             = dgram
        protocol                = udp
        wait                    = yes
        user                    = root
        server                  = /usr/sbin/in.tftpd
        server_args             = -s /tftpboot
        disable                 = no
        per_source              = 11
        cps                     = 100 2
        flags                   = IPv4
}
[root@storage ~]#
</pre>


Restart the xinetd service:-
<pre>
service xinetd restart
chkconfig --level 35 xinetd on
</pre>

Next, we need to copy two special files from a special location of distribution media/repository to /tftpboot directory.
<pre>
[root@storage ~]# ls /data/cdimages/CentOS-5.4-x86_64/images/pxeboot
boot.iso  diskboot.img  minstg2.img  pxeboot  README  stage2.img  TRANS.TBL  xen
[root@storage ~]#
</pre>

We will copy the vmlinuz and initrd.img files, from this location  to /tftpboot directory :-

<pre>
[root@storage ~]# cp /data/cdimages/CentOS-5.4-x86_64/images/pxeboot/* /tftpboot/

[root@storage ~]# ls /tftpboot/ -l
total 9140
-rw-r--r-- 1 root root 7397850 Feb  5 12:41 initrd.img
-rw-r--r-- 1 root root     265 Feb  5 12:41 README
-r--r--r-- 1 root root     659 Feb  5 12:41 TRANS.TBL
-rw-r--r-- 1 root root 1932284 Feb  5 12:41 vmlinuz
[root@storage ~]#
</pre>

The README and TRANS.TBL are not needed, but there is no harm in having them here in /tftpboot/ . 

Basically we need only vmlinuz and initrd.img .



Now is the time to copy the pxelinux.0 file (from the syslinux package) to /tftpboot directory . 

<pre>
# cp /usr/lib/syslinux/pxelinux.0    /tftpboot/
</pre>

Now make sure that all files and direcoties inside /tftpboot is world readable.

<pre>
# chmod +r /tftpboot/* -R

[root@storage tftpboot]# ls -l
total 9152
-rw-r--r-- 1 root root 7397850 Feb  5 12:41 initrd.img
-rw-r--r-- 1 root root   13148 Feb  5 12:53 pxelinux.0
drwxr-xr-x 2 root root    4096 Feb  5 12:48 pxelinux.cfg
-rw-r--r-- 1 root root 1932284 Feb  5 12:41 vmlinuz
[root@storage tftpboot]#
</pre>

(I have removed the README and TRANS.TBL files from /tftpboot to remove clutter).



PXE configuration detail:-
When a client boots, by default it will look for a configuration file from TFTP, with the same name as it's MAC address. 
However, afrer trying several options, it will fall back to requesting a default file, with the name "default". 
This file needs to be in a directory in /tftp of the install server.

</pre>
# mkdir /tftpboot/pxelinux.cfg

# vi /tftpboot/pxelinux.cfg/default
prompt 1
timeout 5
default linux
label  linux
	kernel vmlinuz
	append vga=normal initrd=initrd.img
</pre>

Once these settings are done, you can now try rebooting your client computer and see if it is able to get this TFTP image from this install server. 

You will need to enable PXE boot from the network card in the BIOS of that machine. (This is the defult/intended behavior in an HPCC environment).

Note: If you get TFTP open timeouts on the client machine, (the machine, which is to be installed through PXE boot), then may be you did not start your xinetd service yet. Or may be a firewall issue.


I had my client machine setup to boot from PXE, and here is what I see in /var/log/messages:

<pre>
Feb  5 12:59:54 storage dhcpd: DHCPDISCOVER from 00:13:72:81:3a:3d via eth0
Feb  5 12:59:55 storage dhcpd: DHCPOFFER on 192.168.1.20 to 00:13:72:81:3a:3d via eth0
Feb  5 12:59:58 storage dhcpd: DHCPREQUEST for 192.168.1.20 (192.168.1.100) from 00:13:72:81:3a:3d via eth0
Feb  5 12:59:58 storage dhcpd: DHCPACK on 192.168.1.20 to 00:13:72:81:3a:3d via eth0
Feb  5 12:59:58 storage in.tftpd[19447]: tftp: client does not accept options
</pre>

Note: The message "in.tftpd[19447]: tftp: client does not accept options" , is not an error message. Just information, nothing to worry about.


By doing this, you have managed to start up the interactive installation . Congratulations! 

Please note, this is close to what we want. Read the next section.

= Basic Kickstart = 

We want nodes to install through kickstart, automatically.
And also, we do not want them to get stuck in an install loop for ever. Means, that we want that a node, should only get installed, when it is asked to, and should boot from local disk, when the installation is over.

We will achieve our objectives in steps. First we fix the automatic installation problem, using kickstart.

By default, when a system is installed, there is a file in /root , named anaconda-ks.cfg . We will use the same file as tempelate. Here:

<pre>
cp /root/anaconda-ks.cfg /var/www/html/compute-ks.cfg

[root@storage ~]# vi /var/www/html/compute-ks.cfg
install
text
url --url http://192.168.1.100/CentOS-5.4-x86_64
lang en_US.UTF-8
keyboard us
network --device eth0 --bootproto dhcp
rootpw --iscrypted $1$VQPyk3Ev$JePfY50WaA.aBhKT3xsBq.
firewall --disabled
authconfig --enableshadow --enablemd5
selinux --disabled
timezone Asia/Riyadh
bootloader --location=mbr --driveorder=sda --append=""
# The following is the partition information you requested
# Note that any partitions you deleted are not expressed
# here so unless you clear all partitions first, this is
# not guaranteed to work
zerombr
clearpart --all --initlabel
# part / --fstype ext3 --size=1 --grow
# part swap --size=256
part / --fstype ext3 --size=3000
part swap --size=512
reboot

%packages
@core
</pre>

Make sure that this file is readable by Apache, or world readable.

<pre>
[root@storage ~]# ls -l /var/www/html/
total 8
-rw------- 1 root root 766 Feb  5 13:14 compute-ks.cfg
-rw-r--r-- 1 root root  31 Nov 23 07:31 index.html

[root@storage ~]# chmod +r /var/www/html/*.cfg
</pre>

As you can see that all compute node, as many as ther would be, would install without a hostname, and without a permanent IP assigned to them.
Also as soon as they get installed, they will reboot and go through another install cycle. Which is not desired. However, before we go on and solve that issue, lets try to install the node as per above configuration.
You will need to modify the /tftpboot/pxelinux.cfg/default file as :-


Edit the tftpboot file again and add extra options:-

<pre>
[root@headnode ~]# vi /tftpboot/pxelinux.cfg/default

prompt 1
timeout 5
default linux
label  linux
        kernel vmlinuz
        append vga=normal initrd=initrd.img ip=dhcp ksdevice=eth0 ks=http://192.168.1.100/compute-ks.cfg
</pre>

Reboot your client machine and see the magic. You should be able to see activity in the apache access_log. Entries such as following:-

<pre>
[root@storage ~]# tail -f /var/log/httpd/access_log
. . . 
. . . 
192.168.1.20 - - [05/Feb/2010:13:22:41 +0300] "GET /CentOS-5.4-x86_64/CentOS/pcsc-lite-libs-1.4.4-0.1.el5.x86_64.rpm HTTP/1.1" 200 24120 "-" "urlgrabber/3.1.0 yum/3.2.22"
. . .
. . . 
</pre>

During this install session, I was able to see the following as the last entries in the apache access_log :-

<pre>
192.168.1.20 - - [05/Feb/2010:13:24:54 +0300] "GET /CentOS-5.4-x86_64/CentOS/NetworkManager-0.7.0-9.el5.x86_64.rpm HTTP/1.1" 200 1099937 "-" "urlgrabber/3.1.0 yum/3.2.22"
192.168.1.20 - - [05/Feb/2010:13:24:54 +0300] "GET /CentOS-5.4-x86_64/CentOS/NetworkManager-glib-0.7.0-9.el5.i386.rpm HTTP/1.1" 200 83448 "-" "urlgrabber/3.1.0 yum/3.2.22"
</pre>

As you might guess, these entries may vary as per the installation packages selected. In other words, it is not guaranteed that NetworkManager would be the last package obtained from the repository during an install. 

Basically I am trying to tell you that we need to find/device a way so we know that when installation of a particular node is complete.


End of day.

Here are things to do / ideas:

* Create a text file of all hostnames, IP and MAC addresses, delimited by  a space.
* Create a program perl/bash, which will read this file and generates a proper kickstart and related tftpboot file in /tftpboot/pxelinux.cfg/ directory.
* Create a small text file and make it available in the /var/www/html directory, which will be pulled and copied to the installed node in /tmp, during  (at the end of) the %post.
* Some program should constantly monitor the apache logs and check if a node accesses this file. When some node accesses this file, that means that the   node is now completed installation and it's tftpboot file can be removed.
* This also means that the default tftpboot file should only contain a boot from local disk option. This way if some nodes mac-based tftp file is removed, its  PXE will fall through and land on the default, which will make it boot from the local disk. This should do it.

Will work on this next day.

= Digging deep in the TFTP trenches + log-monitoring tools = 

I created a file /tftpboot/pxelinux.cfg/00-13-72-81-3a-3d , with the following contents:

<pre>
[root@storage pxelinux.cfg]# cat 00-13-72-81-3a-3d
prompt 1
timeout 10
default linux
label  linux
        kernel vmlinuz
        append vga=normal initrd=initrd.img ip=dhcp ksdevice=eth0 ks=http://192.168.1.100/compute-ks.cfg

[root@storage pxelinux.cfg]#
</pre>

The file named "default" is modified to look like this:

<pre>
[root@storage pxelinux.cfg]# cat default
prompt 1
timeout 10
default localdisk
label localdisk
    localboot 0
</pre>


However, when I rebooted the client, the TFTP client did was infact searching for a file named "01-00-13-72-81-3a-3d" . This was strange. I renamed the file 00-13-72-81-3a-3d to 01-00-13-72-81-3a-3d. Rebooted the client and it installed correctly.

Note: The "01", before the MAC address represents a hardware type of "ethernet".


As soon as I saw that it is about to finish, I renamed the PXE boot filename so the TFTP boot client will not load the mac-based file and instead fall through to load the default file.

<pre>
[root@storage pxelinux.cfg]# mv 01-00-13-72-81-3a-3d 01-00-13-72-81-3a-3d.orig
</pre>


Created a html file /var/www/html/lastpackage.html: ( Actually it doesn't have to be an html file )

<pre>
[root@storage html]# cat lastpackage.html
This is the last file, which is downloaded from the client, during installation. When it is downloaded, it means that the installation is complete and now the mac-based tftp installation file can be removed from /tftpboot/pxelinux.cfg/.
[root@storage html]#
</pre>

I see the following entry in the apache access_log file when the node is done installation.

<pre>
[root@storage html]# tail -f /var/log/httpd/access_log
. . . 
. . . 
192.168.1.20 - - [06/Feb/2010:02:52:33 +0300] "GET /CentOS-5.4-x86_64/CentOS/NetworkManager-0.7.0-9.el5.x86_64.rpm HTTP/1.1" 200 1099937 "-" "urlgrabber/3.1.0 yum/3.2.22"
192.168.1.20 - - [06/Feb/2010:02:52:34 +0300] "GET /CentOS-5.4-x86_64/CentOS/NetworkManager-glib-0.7.0-9.el5.i386.rpm HTTP/1.1" 200 83448 "-" "urlgrabber/3.1.0 yum/3.2.22"
192.168.1.20 - - [06/Feb/2010:02:52:36 +0300] "GET /lastpackage.html HTTP/1.0" 200 240 "-" "Wget/1.11.4 Red Hat modified"
. . . 
192.168.1.20 - - [06/Feb/2010:02:52:36 +0300] "GET /lastpackage.html HTTP/1.0" 200 240 "-" "Wget/1.11.4 Red Hat modified"
</pre>


If I can now make a small program, which could monitor this log file and remove the mac-based tftp file as soon as it sees this entry, it would be superb.

First, I need to have a translation file, having IP, hostname and MAC information  in it.

<pre>
[root@storage ~]# vi /root/host-ip-mac.txt
# Format of this file is :
# hosntname IP MAC
# hostname a.b.c.d aa-bb-cc-dd-ee-ff
kvm     192.168.1.20    00-13-72-81-3a-3d


[root@storage ~]# egrep -v "#|^$"  /root/host-ip-mac.txt
kvm     192.168.1.20    00-13-72-81-3a-3d
[root@storage ~]#
</pre>


Here is a bit of demo, how can I select different columns:
<pre>
[root@storage ~]# egrep -v "#|^$"  /root/host-ip-mac.txt  |awk '{print $1}'
kvm

[root@storage ~]# egrep -v "#|^$"  /root/host-ip-mac.txt  |awk '{print $2}'
192.168.1.20

[root@storage ~]# egrep -v "#|^$"  /root/host-ip-mac.txt  |awk '{print $3}'
00-13-72-81-3a-3d
</pre>

Now I needed a log file monitoring tool, which I can use to monitor the apache log file and take an action when a match is found. 

I found few software with announced capability of what I was looking for. These are logtail, log-guardian, swatch. I found all of them in capable of what I wanted to do. (Or, I was in-capable of getting my task done using these software).


I find log-guardian to be complicated. Just to be complete, I am showing below, what I experienced.

<pre>
[root@storage ~]# wget http://www.tifaware.com/code/log-guardian/log-guardian -P /root

chmod +x /root/log-guardian

[root@storage ~]# ./log-guardian
Can't locate File/Tail.pm in @INC (@INC contains: /usr/lib64/perl5/site_perl/5.8.8/x86_64-linux-thread-multi /usr/lib/perl5/site_perl/5.8.8 /usr/lib/perl5/site_perl /usr/lib64/perl5/vendor_perl/5.8.8/x86_64-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.8 /usr/lib/perl5/vendor_perl /usr/lib64/perl5/5.8.8/x86_64-linux-thread-multi /usr/lib/perl5/5.8.8) at ./log-guardian line 144.
BEGIN failed--compilation aborted at ./log-guardian line 144.
[root@storage ~]#


Log Guardian needs Tail.pm .

[root@storage ~]# wget http://search.cpan.org/CPAN/authors/id/M/MG/MGRABNAR/File-Tail-0.99.3.tar.gz -P /root/     


[root@storage ~]# tar xzf File-Tail-0.99.3.tar.gz

[root@storage ~]# cd File-Tail-0.99.3

[root@storage File-Tail-0.99.3]# perl Makefile.PL

[root@storage File-Tail-0.99.3]# make

[root@storage File-Tail-0.99.3]# make install
Installing /usr/lib/perl5/site_perl/5.8.8/File/Tail.pm
Installing /usr/share/man/man3/File::Tail.3pm
Writing /usr/lib64/perl5/site_perl/5.8.8/x86_64-linux-thread-multi/auto/File/Tail/.packlist
Appending installation info to /usr/lib64/perl5/5.8.8/x86_64-linux-thread-multi/perllocal.pod
[root@storage File-Tail-0.99.3]#
</pre>


Swatch seems to be the other alternative:- (rpmforge repository) or direct download.

Help: http://linsec.ca/Using_swatch_to_Monitor_Logfiles

<pre>
wget http://sourceforge.net/projects/swatch/files/swatch/3.2.3/swatch-3.2.3.tar.gz/download

[root@storage swatch-3.2.3]# perl Makefile.PL
Checking if your kit is complete...
Looks good
Warning: prerequisite Date::Calc 0 not found.
Warning: prerequisite Date::Format 0 not found.
Warning: prerequisite Date::Manip 0 not found.
Writing Makefile for swatch
[root@storage swatch-3.2.3]#

[root@storage swatch-3.2.3]# yum -y install perl-Date-Calc perl-DateManip perl-HTML-Parser perl-TimeDate perl-XML-Parser


[root@storage swatch-3.2.3]# perl Makefile.PL
Writing Makefile for swatch
[root@storage swatch-3.2.3]#


make
make install


[root@storage ~]# cat /usr/local/etc/swatch.conf
watchfor   /lastpackage.html /
        echo
[root@storage ~]#

[root@storage ~]# swatch --config-file=/usr/local/etc/swatch.conf --tail-file=/tmp/swatch.log --script-dir=/usr/local/swatch/
</pre>

I created a script, which would take in an IP and remove the corresponding tftp file .

<pre>
[root@storage swatch]# cat /usr/local/swatch/remove-tftp-file.sh
#!/bin/bash
MAPFILE=/root/host-ip-mac.txt
IP=$1
echo "Recieved IP is: ${IP}"
MAC=$(grep ${IP} ${MAPFILE} | awk '{print $3}' )
TFTPMACFILE="01-${MAC}"
echo "Executing: rm -f /tftpboot/pxelinux.cfg/${TFTPMACFILE}"
[root@storage swatch]#
</pre>

swatch was still unable to execute my script.

= My own log monitoring tool = 

I think I was wasting my time on log readers. So I decided to use the perl Tail module directly and write my own tool.

Using: http://search.cpan.org/~mgrabnar/File-Tail-0.99.3/Tail.pm

And the methods defined in it, I have a working piece of code to simulate "tail -f" . Here it is:

<pre>
[root@storage tmp]# cat logwatch.pl
#!/usr/bin/perl -w
  use File::Tail;
  $name="/tmp/swatch.log";
  ## $file=File::Tail->new(name=>$name, maxinterval=>300, adjustafter=>7);
  $file=File::Tail->new(name=>$name,maxinterval=>1,interval=>1,adjustafter=>2);
  while (defined($line=$file->read)) {
      print "$line";
  }
[root@storage tmp]#
</pre>

What I need to do now, is to check for a match , such as last package.html, and then remove the tftp file.

= Day 5. A lot of progress! = 

I have (almost) perfected the logwatch program. Now I need a total of three files to provision nodes. 

# logwatch.pl (This watches if the node is done installation, then it deletes it's TFTP file).
# host-ip-mac.txt (This is the MAP file for nodes in the format of: hostname IP MAC)
# create-kickstart.sh (This one creates the TFTP and KS file for the node to be provisioned.)

Note: The only (basic) thing pending is that the encrypted root password gets changed in the target kickstart file. It is probably because of the $ signs in it. I have to find a way to escape the $ signs in it.

Here it is the much perfected logwatch program. It needs to be kept running in a separate terminal, when the provisioning of nodes is being done.

<pre>
[root@storage tmp]# cat logwatch.pl                                     
#!/usr/bin/perl -w                                                      
use File::Tail;                                                         
$mapfile="/tmp/host-ip-mac.txt";                                        
$TFTPDIR="/tftpboot/pxelinux.cfg/";                                     
unless(open(MAPFILE,"$mapfile"))                                        
  {                                                                     
  die "Could not open $mapfile input log file.";                        
  }                                                                     
close(MAPFILE);                                                         

$logfile="/var/log/httpd/access_log";
# $logfile="/tmp/swatch.log";        
## $file=File::Tail->new(name=>$logfile, maxinterval=>300, adjustafter=>7);
$LOGFILE=File::Tail->new(name=>$logfile,maxinterval=>1,interval=>1,adjustafter=>1);
while (defined($line=$LOGFILE->read)) {                                            
  chomp($line);                                                                    
  # if ( $line =~ m/lastpackage/) {                                                
  # if ( $line =~ m/(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}) [A-Z,a-z,-,0-9,/,:,+,", ]+ GET lastpackage/) {
  if ( $line =~ m/(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}).*lastpackage/) {                                
    $IP=$1;                                                                                            
    print "This was last package. IP is $IP .\n";                                                      
    print "$line\n";                                                                                   
    print "It is now safe to delete the tftp file.\n";                                                 
    # Find the MAC address of this IP from the mapfile.                                                
    open(MAPFILE,"<$mapfile");
    print "MAPFILE opened.\n";
    while ($mapline = <MAPFILE>) {
      chomp ($mapline);
      # do something with $mapline
      # Skip line if it starts with #
      if ($mapline =~ m/^#/) {
        # print "Found a line starting with # sign. Skipping loop.\n";
        next;
       }
      if ($mapline =~ m/([A-Z,a-z,0-9,-]+)\s+(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})\s+(.*)/) {
          $MAPHOST=$1;
          $MAPIP=$2;
          $MAPMAC=$3;
        if ("$MAPIP" eq "$IP") {
          print "Found match: HOSTNAME= $MAPHOST  IP= $MAPIP MAC= $MAPMAC \n";
          $TFTPFILE="$TFTPDIR" . "01-" . "$MAPMAC";
          print "Full path to TFTP file (including filename) would be: $TFTPFILE\n";
        }
      }
    }
    close(MAPFILE);
    print "MAPFILE closed.\n";
    # Time to delete the file
    unlink("$TFTPFILE");
    print "File deleted: $TFTPFILE \n";
  }
}
[root@storage tmp]#
</pre>


The MAP-file is actually the following:-

<pre>
[root@storage tmp]# cat host-ip-mac.txt
# Format of this file is :
# hostname IP MAC
# hostname a.b.c.d aa-bb-cc-dd-ee-ff
kvm     192.168.1.20    00-13-72-81-3a-3d
demo    192.168.1.33    00-13-3e-7a-e2-12

[root@storage tmp]#
</pre>


And the script to generate kickstart files:-

<pre>
[root@storage tmp]# cat create-kickstart.sh                  
#!/bin/bash                                                  
# Start - USerConfiguration ####################################
# Use /sbin/grub-md5-crypt to generate a password and copy here.
ROOTPASSWORD="$1$VQPyk3Ev$JePfY50WaA.aBhKT3xsBq."               
NETMASK="255.255.255.0"                                         
MAPFILE="/tmp/host-ip-mac.txt"                                  
HOSTNAME=$1                                                     
CONSOLEOPTIONS="console=ttyS2,57600n8r"                         
TFTPDIR="/tftpboot/pxelinux.cfg/"                               
# WEBSERVER is needed for kickstart files loading               
WEBREPOSITORY="CentOS-5.4-x86_64"                               
WEBDIR="/var/www/html"                                          
WEBSERVER="192.168.1.100"                                       
GATEWAY=${WEBSERVER}                                            
KSDEVICE="eth0"                                                 
# KSOPTIONS="serial syslog=192.168.1.100"                       
KSOPTIONS="text"                                                
# Note: When using syslog=<IP> option, the syslog service on <IP> should be configured 
# to listen to remote connections.                                                     
# This can be done by using SYSLOGD_OPTIONS="-m 0 -r" in /etc/sysconfig/syslog  file.  
# Restart syslog service after that.                                                   

# PACKAGEOPTIONS="--nobase"
# Note: "--nobase" causes %post to not execute. At least that is what I am experiencing.
PACKAGEOPTIONS="--excludedocs"                                                          


#
# End - UserConfiguration #######################################
#                                                                
#                                                                

if [ "$HOSTNAME" == "" ] ; then
  echo "You must provide a hostname from the map file to generate kickstart."
  exit 1                                                                     
fi                                                                           

############

# Find the IP and MAC of this hostname
MAPIP=$(egrep -v "#|^$"  $MAPFILE | grep ${HOSTNAME} | awk '{print $2}')
MAPMAC=$(egrep -v "#|^$"  $MAPFILE | grep ${HOSTNAME} |  awk '{print $3}')
if [ "${MAPIP}" == "" ] ; then                                            
  echo "This hostname does not exist in the MapFile $MAPFILE"             
  exit 1                                                                  
fi                                                                        

###### 
echo "Found the following information about this node:-"
echo "Hostname (Provided): $HOSTNAME"                   
echo "IP address         : $MAPIP"                      
echo "MAC address        : $MAPMAC"                     
echo                                                    

# http://www.centos.org/docs/5/html/Installation_Guide-en-US/s1-kickstart2-startinginstall.html

#Create a TFTP file:-

TFTPFILE="${TFTPDIR}/01-${MAPMAC}"


cat > $TFTPFILE << TFTPEOF
prompt 1                  
timeout 5                 
default linux             
label  linux              
        kernel vmlinuz    
        append vga=normal initrd=initrd.img noipv6 kssendmac ip=${MAPIP} netmask=${NETMASK} gateway=${GATEWAY} ksdevice=${KSDEVICE} ks=http://${WEBSERVER}/${HOSTNAME}-ks.cfg ${KSOPTIONS}                                          
TFTPEOF                                                                                                           

chmod +r $TFTPFILE

echo "Generated the following TFTP file (with full path): ${TFTPFILE}"
echo "TFTP File - Start"                                              
cat $TFTPFILE                                                         
echo "TFTP File - End"                                                


# Create the related kickstart file now:
# http://www.centos.org/docs/5/html/Installation_Guide-en-US/s1-kickstart2-options.html

KSFILE="${WEBDIR}/${HOSTNAME}-ks.cfg"

cat > $KSFILE << KSEOF
# kickstart file automatically generated by anaconda.                                                             
install                                                                                                           
text                                                                                                              
url --url http://${WEBSERVER}/${WEBREPOSITORY}                                                                    
lang en_US.UTF-8                                                                                                  
keyboard us                                                                                                       

# Can we have two network lines for two different interfaces? : Yes
# http://www.linux-archive.org/centos/239241-kickstart-wont-kick-off-via-network.html
network --device ${KSDEVICE} --noipv6 --nodns --bootproto static --hostname=${HOSTNAME} --ip=${MAPIP} --netmask=${NETMASK} --gateway=${GATEWAY}                                                                                     
# Second network card, which you might want to keep off during boot:-                                             
# network --device eth1 --noipv6 --nodns --bootproto static --onboot=no                                           

# root password is globbing / changing automatically. Something to do with $ signs.
# rootpw --iscrypted ${ROOTPASSWORD}                                               
rootpw --iscrypted $1$VQPyk3Ev$JePfY50WaA.aBhKT3xsBq.                              
firewall --disabled                                                                
authconfig --enableshadow --enablemd5                                              
selinux --disabled                                                                 
timezone Asia/Riyadh                                                               
bootloader --location=mbr --driveorder=sda --append=""                             
# The following is the partition information you requested                         
# Note that any partitions you deleted are not expressed                           
# here so unless you clear all partitions first, this is                           
# not guaranteed to work                                                           
zerombr                                                                            
clearpart --all --initlabel                                                        
# part / --fstype ext3 --size=1 --grow                                             
# part swap --size=256                                                             
part / --fstype ext3 --size=2500                                                   
part swap --size=512                                                               
reboot

%packages ${PACKAGEOPTIONS}
@core

%post
sed -i 's/^splashimage/#splashimage/g' /etc/grub.conf
sed -i 's/^hiddenmenu/#hiddenmenu/g' /etc/grub.conf
sed -i 's/rhgb quiet//g' /etc/grub.conf

for i in autofs avahi-daemon bluetooth cups firstboot hidd iptables ip6tables netfs nfslock pcscd portmap rawdevices restorecond rpcgssd rpcidmapd sendmail smartd ; do chkconfig --level 35 \$i off; done

wget http://${WEBSERVER}/lastpackage.html -P /tmp/

KSEOF

chmod +r $KSFILE

echo "Kickstart file for this node created as ${KSFILE}. Since it is a long file, I am not displaying it here."

# It is also important that the lastpackage.html file exists in the webdir. This is used by my logwatch program.

echo "This is last package" > ${WEBDIR}/lastpackage.html
chmod +r ${WEBDIR}/lastpackage.html

echo "Configuration complete. Reboot the node ${HOSTNAME} to install it. Have fun!"
exit 0
[root@storage tmp]#
</pre>