Tool support for image creation

Oz Oz is a command-line tool that automates the process of creating a virtual machine image file. Oz is a Python app that interacts with KVM to step through the process of installing a virtual machine. It uses a predefined set of kickstart (Red Hat-based systems) and preseed files (Debian-based systems) for operating systems that it supports, and it can also be used to create Microsoft Windows images. On Fedora, install Oz with yum:# yum install oz As of this writing, there are no Oz packages for Ubuntu, so you will need to either install from source or build your own .deb file. A full treatment of Oz is beyond the scope of this document, but we will provide an example. You can find additional examples of Oz template files on github at rackerjoe/oz-image-build/templates. Here's how you would create a CentOS 6.4 image with Oz. Create a template file (we'll call it centos64.tdl) with the following contents. The only entry you will need to change is the <rootpw> contents.<template> <name>centos64</name> <os> <name>CentOS-6</name> <version>4</version> <arch>x86_64</arch> <install type='iso'> <iso>http://mirror.rackspace.com/CentOS/6/isos/x86_64/CentOS-6.4-x86_64-bin-DVD1.iso</iso> </install> <rootpw>CHANGE THIS TO YOUR ROOT PASSWORD</rootpw> </os> <description>CentOS 6.4 x86_64</description> <repositories> <repository name='epel-6'> <url>http://download.fedoraproject.org/pub/epel/6/$basearch</url> <signed>no</signed> </repository> </repositories> <packages> <package name='epel-release'/> <package name='cloud-utils'/> <package name='cloud-init'/> </packages> <commands> <command name='update'> yum update yum clean all sed -i '/^HWADDR/d' /etc/sysconfig/network-scripts/ifcfg-eth0 echo -n > /etc/udev/rules.d/70-persistent-net.rules echo -n > /lib/udev/rules.d/75-persistent-net-generator.rules </command> </commands> </template> This Oz template specifies where to download the Centos 6.4 install ISO. Oz will use the version information to identify which kickstart file to use. In this case, it will be RHEL6.auto. It adds EPEL as a repository and install the epel-release, cloud-utils, and cloud-init packages, as specified in the packages section of the file. After Oz does the initial OS install using the kickstart file, it customizes the image by doing an update. It also removes any reference to the eth0 device that libvirt creates while Oz does the customizing, as specified in the command section of the XML file. To run this, do, as root: # oz-install -d3 -u centos64.tdl -x centos64-libvirt.xml The -d3 flag tells Oz to show status information as it runs. The -u tells Oz to do the customization (install extra packages, run the commands) once it does the initial install. The -x <filename> flag tells Oz what filename to use to write out a libvirt XML file (otherwise it will default to something like centos64Apr_03_2013-12:39:42). If you leave out the -u flag, or you want to edit the file to do additional customizations, you can use the oz-customize command, using the libvirt XML file that oz-install creates. For example: # oz-customize -d3 centos64.tdl centos64-libvirt.xml Oz will invoke libvirt to boot the image inside of KVM, then Oz will ssh into the instance and perform the customizations.