Automate Mass Server Deployments with Cobbler: A Step‑by‑Step Guide

Preface

Operations automation is becoming increasingly important in enterprise production environments; provisioning hundreds or thousands of servers manually is unimaginable, and Cobbler satisfies this need for batch machine deployment.

Introduction

Cobbler is a free, open‑source system installation and deployment software that automates network OS installations. Developed in Python, it wraps PXE, offering CLI, Web UI, and API interfaces for easy integration and secondary development. It can install physical machines, virtual guests, and GuestOS, and can be combined with centralized management tools such as Puppet.

Cobbler component relationships:

Installation Process

Install Cobbler (requires EPEL repository, which pulls dependencies such as tftp‑server, httpd, dhcp, rsync, etc.):

[root@node0 ~]# yum install cobbler pykickstart debmirror dhcp rsync cman fence-agents
[root@node0 ~]# service httpd start
[root@node0 ~]# chkconfig tftp on
[root@node0 ~]# chkconfig rsync on

Configure Cobbler:

[root@node0 ~]# vim /etc/cobbler/settings
server: 192.168.1.4
next_server: 192.168.1.4

[root@node0 ~]# cobbler get-loaders

[root@node0 ~]# vim /etc/debmirror.conf
#@dists="sid";
#@arches="i386";

[root@node0 ~]# openssl passwd -1 -salt `openssl rand -hex 4`
$1$ca6a7d72$KDte4ZK00OCLiK4PLE4tp0
[root@node0 ~]# vim /etc/cobbler/settings
default_password_crypted: "$1$ca6a7d72$KDte4ZK00OCLiK4PLE4tp0"

[root@node0 ~]# service cobblerd start
[root@node0 ~]# chkconfig cobblerd on
[root@node0 ~]# cobbler sync

Configure DHCP:

[root@node0 ~]# cp /usr/share/doc/dhcp-4.1.1/dhcpd.conf.sample /etc/dhcp/dhcpd.conf
[root@node0 ~]# vim /etc/dhcp/dhcpd.conf
subnet 192.168.1.0 netmask 255.255.255.0 {
    range 192.168.1.1 192.168.1.100;
    option routers 192.168.1.1;
    next-server 192.168.1.4;
    filename "pxelinux.0";
}
[root@node0 ~]# service dhcpd start
[root@node0 ~]# chkconfig dhcpd on

Add distro: mount the installation ISO and import it into Cobbler.

[root@node0 ~]# mount /mnt/hgfs/lin/CentOS-6.7-x86_64-bin-DVD1.iso /mnt/cdrom/
[root@node0 ~]# cobbler import --name=CentOS-6.7-x86_64 --path=/mnt/cdrom/ --kickstart=/root/anaconda-ks.cfg
task started: 2016-03-08_203724_import
task started (id=Media import, time=Tue Mar  8 20:37:24 2016)
Found a candidate signature: breed=redhat, version=rhel6
Found a matching signature: breed=redhat, version=rhel6
Adding distros from path /var/www/cobbler/ks_mirror/CentOS-6.7-x86_64:
skipping import, as distro name already exists: CentOS-6.7-x86_64
No distros imported, bailing out
!!! TASK FAILED !!!

View current distro list:

[root@node0 ~]# cobbler distro list
CentOS-6.7-x86_64

Test Installation