Creating a KVM Ubuntu VM using Debootstrap

This repository contains scripts to automatically create a KVM image based on the parameters specified in config.sh.

The overall process is described here.

Requirements:

• Debian/Ubuntu starting system
• $ sudo apt-get install debootstrap grub germinate reprepro kpartx uml-utilities qemu-kvm parprouted
• sudo

Running these scripts

To run these scripts first set some local variables in your environment used to create and configure the guest. The default configuration comes from config.bash, but the key elements are set in the environment using the guest.sh script. This will also save the configured setting in guests/.params. This parameter file can then be used to lauch a shell using: ./guest.sh --shell -f guests/.params

To see the guest.sh usage:

$ ./guest.sh
Usage: ./guest.sh -v  -d  -s  -m  -g  -n 

   Start a /bin/bash shell with a configured environment.
     ./guest.sh --shell -v  -d  -s  -m  -g  -n 

Next create a shell environment to run the scripts in.

$ ./guest.sh --shell -v VM01
[INFO ] Using a root directory of .../ubuntu-bootstrap
[INFO ] Loading configuration from .../ubuntu-bootstrap/config.bash
Using Ubuntu
  Release      : maverick
  Architecture : amd64
  Mirror       : http://gb.archive.ubuntu.com/ubuntu

Using network configuration
  hostname  : VM01
  domain    : example.com
  fqdn      : VM01.example.com
  static-ip : 10.80.20.201
  netmask   : 255.255.255.0
  gateway   : 10.80.20.1
  nameserver: 10.80.20.10

At this point make any modifications to additional.packages and run through the scripts 01-..., 02-..., 03-...,04-..., etc.

Care has been put into these scripts to check the output of each command. So that they should fail fast if something goes wrong.

01-create-boostrap-mirror.bash
02-create-kvm-disk-image.bash
03-install-ubuntu.bash
04-configure-basics.bash
05-install-additional-packages.bash
06-install-grub.bash
07-final-touches.bash

Booting the vm

Booting with out the network card. The root password should be set to gotcha12.

kvm -drive file=ubuntu-maverick-amd64.img,index=0,media=disk -m 256m

See: 'Wireless Bridge for Laptop Hosts' at end of this article for the setup of a network taped interface here.

kvm -drive file=ubuntu-maverick-amd64.img,index=0,media=disk \
    -net tap,ifname=tap0,script=no,downscript=no -net nic \
    -m 256m

Post Boot

At this point the network should be available from within the VM. If that is working then the apt cache should be updated against the mirror. And the root password should be changed.

As root

# aptitude update
# passwd

Helping out

Ideas, suggestions, bug fixes are all welcome.

Working with Partial Installs

The scripts are intended to be run one after another, but during testing it is sometimes handy to rerun bits of the process to fine tune the result.

Updating the Additional Packages List

If you find that part way through the installation process you would like additional packages. You can modify additional.packages or mirror.packages and re-run 01-create-boostrap-mirror.bash the new packages will be downloaded and mirror updated. This process should only take a small amount of time as only the new packages will be downloaded.

Re-running the script will also download new updates for previously mirrored packages.

Issues

I. The kernel image is failing to install.

I had this issue in one VM and got around it by specifying an exact kernel in additional.packages, rerunning step 01, and then step 05.

Utilities

The following utility scripts are useful for dealing with the choot VM.

• 10-mount-image.bash -- Mounts the VM in the host
• 11-umount-image.bash -- Unmounts the VM in the host
• 12-chroot.bash -- Chroot into a mounted VM (Can be run standalone)