Packer for KVM/libvirt

Builds KVM (qcow2) images

Concepts initially borrowed from: https://github.com/stardata/packer-centos7-kvm-example https://github.com/goffinet/packer-kvm

Setup

Install packer https://learn.hashicorp.com/tutorials/packer/getting-started-install

sudo yum install -y yum-utils
sudo yum-config-manager --add-repo https://rpm.releases.hashicorp.com/RHEL/hashicorp.repo
sudo yum -y install packer

System-level packages for libvirt/kvm/quemu

sudo yum -y install epel-release
sudo yum -y install libvirt libguestfs-tools qemu-kvm qemu-system-x86  virt-install virt-manager virt-viewer

Build directory structure

Each build is contained in its own sub-directory. All files for the build live in that directory.

For CentOS/RHEL builds the directory structure looks like:

centos-X/http/centos-X-kickstart.cfg  # RHEL Kickstart file
centos-X/centos-X-template.json   # packer template file, describes how to build the VM template

Building

Prior to building, you may want to edit the template file and adjust any variables that are necessary to tweak.

This will download the ISO needed to build the template (packer caches these ISOs). If you would like to use a local ISO, you can download the ISO yourself and tweak the iso_urls variable in the format: file:///path/to/my.iso, see the QEMU builder docs

packer build ./centos-8/centos-8-template.json

The output will be written to:

packer-centos-8-template/packer-centos-8-template.img

If you would like this image available to the system, simply copy it into the standard image path:

sudo cp packer-centos-8-template/packer-centos-8-template.img /var/lib/libvirt/images

The reason we don't default to putting images into /var/lib/libvirt/images is that Packer would need to be run as root. This is possible and easy to configure using the output_directory option in the template file.