Prefetch Technologies // Keeping your cache lines cozy

Cobbler Notes

Dec 11, 2017

Getting cobbler installed and configured is pretty easy. Here are the steps I typically use on a Fedora-derived system:

Install cobbler and httpd

$ yum -y install cobbler httpd fence-agents debmirror

Enable TFTP services

$ sed -i 's/^\(.*disable.*=\).*/\1 no/' /etc/xinetd.d/tftp

Start and enable services

$ systemctl enable cobblerd.service

$ systemctl start cobblerd.service

$ systemctl enable httpd

$ systemctl start httpd

$ systemctl enable tftp

$ systemctl start tftp

Edit the cobbler configuration file to suit your needs

$ vi /etc/cobbler/settings

Run cobbler to see how it feels about your settings

$ cobbler check

Synchronize content

$ cobbler sync

Import an initial image (CentOS 7 in this case)

$ mount -o loop CENTOS_DVD /mnt

$ cobbler import --name=centos7 --arch=x86_64 --path=/mnt

Check to make sure the distribution imported

$ cobbler distro list

$ cobbler distro report --name=centos7

Add a system to cobbler

You can use cobbler system add to create a new system:

$ cobbler system add --name=$FQDN --profile=$PROFILE --mac=$MACADDR \
  --ip-address=$IPADDR --netmask=$NETMASK --static=1 --dns-name=$FQDN \
  --gateway=$GATEWAY --interface=$INTERFACE \
  --name-servers-search="prefetch.net" \
  --kickstart="/var/lib/cobbler/kickstarts/${profile}.ks" \
  --name-servers=$DNS_SERVERS

To verify the system is present you can use the report option:

$ cobbler system report $FQDN

If everything succeeded up to this point you should be able to PXE boot your host.

Add snippet to apply base ansible CM policy

$ cat /var/lib/cobbler/snippets/post_installation_tasks

echo "Applying the latest set of system updates to the server"
/usr/bin/dnf -y update

if [$? -ne 0]; then
   exit 1
fi


echo "Installing ansible to manage our systems"
/usr/bin/dnf -y install ansible

if [$? -ne 0]; then
   exit 1
fi

echo "Installing git to pull down our configuration repository"
dnf -y install git

if [$? -ne 0]; then
   exit 1
fi

echo "Running ansible to lay down the base system configuration"
mkdir /ansible && cd /ansible

git clone https://myrepo/ansible

if [$? -ne 0]; then
   exit 1
fi

ansible-playbook site.yml

if [$? -ne 0]; then
   exit 1
fi

This document assumed a couple of items

  • You are running an external ISC DHCP server and the next-server and filename DHCP options are populated. You modified the sample.ks and created a new kickstart profile in /var/lib/cobbler/kickstarts The document assumes you are familiar with the settings file which is discussed at length in the official documentation