Ubuntu Templates

Ubuntu 20.04 Server

Ubuntu 20.04 is a distro used by a number of Dropship modules by default. These instructions should be valid for any version 18.04+.

Installation

In my templates, I configured the user to be adminuser, to help differentiate it from other default users, as well as named the system template. This name should be changed via a Dropship module. I also did NOT use LVM, which seems to not use the entire disk by default. However, you are free to use whatever configuration fits your environment.

Networking

First, we need to set Ubuntu to use the ethX pattern, which is much more predictable. We can do this by editing the GRUB_CMDLINE_LINUX line in the file /etc/default/grub to:

GRUB_CMDLINE_LINUX="net.ifnames=0 biosdevname=0"

Then we need to update GRUB config, so the commands we need are:

sudo vi /etc/default/grub
sudo grub-mkconfig -o /boot/grub/grub.cfg

(Source)

One of the more important items is to configure netplan to use the MAC address instead of the system ID. This ensures that when we clone, we will get a different IP for different instances. Do this by adding the following line to /etc/netplan/00-installer-config.yaml, on the same level as the `` `` line:

dhcp-identifier: mac

While we are editing this file, we should change the interface name to eth0 So the file should now look like this:

network:
  ethernets:
      eth0:
        dhcp4: true
        dhcp-identifier: mac
  version: 2

After this, reboot the machine so the interface naming will change.

“Sysprep”

Note

Before I run Sysprep, I usually create a snapshot of the VM, so I can revert if I forgot something. This is to save time for regenerating things (especially on Windows, which not only takes a very long time, but also has a sysprep limit)

While this is usually a term used with Windows, modern Ubuntu systems have a number of items that should be cleaned before cloning, such as the machine ID, logs, and SSH keys. These steps are being gathered into scripts at this repo. We can use the Ubuntu 18.04, and utilize the shortened links:

wget https://bit.ly/2OAKLkA -O sysprep.sh
chmod +x sysprep.sh
./sysprep.sh