Many premade cloud images (e.g. Fedora Cloud, Ubuntu Cloud) use some form of cloud-init to set instance/user metadata, such as hostnames and SSH keys. This works well when used in a cloud infrastructure such as EC2 or OpenStack that can seed this data, but not so well when used for local VMs, or an out-of-the-box XenServer installation.
However, cloud-init supports an CD/ISO datasource, which can be loaded whether running the machine locally in KVM, VirtualBox, or on a XenServer host.
This repository and guide aims to make this task a lot easier by pre-seeding a template and script. It draws heavily on existing resources (2, 3).
K3os is Rancher Labs' bespoke operating system for running the tiny K8s distro k3s.
When configured to use cloud-init with k3os.data_sources=cdrom, the embedded version
of linuxkit/metadata is requiring a file called config in the top level of the ISO.
That's why this fork is needed: create a hard link from user-data to config
before making the ISO image. (Bonus info: for Suse Linux use mkisofs.)
Example: run k3os-build.sh K3os-091-a to generate an ISO file called cidata-K3os-091-a.iso
You need genisoimage installed. For RHEL, CentOS, Fedora, Oracle Linux, etc.,
sudo dnf install genisoimage (use yum if you are on RHEL/CentOS/OL 7). For
Ubuntu, Debian, and derivatives thereof, sudo apt install genisoimage.
- Clone this repository. (optional: maybe create and checkout your own branch?)
- Modify the
meta-dataYAML file to specify yourinstance-idandlocal-hostname. - Modify the
user-dataYAML file -- according to cloud-config syntax -- to specify a password and/or SSH keys. The cloud image determines the default user's login name, but you can override that according to the cloud-config documentation. - (optional) Commit your changes in git. This helps the build script name your ISO.
- Build the ISO using
./build.sh. You can either specify an output filename as the first parameter (e.g../build.sh output-file.iso), or you can let the script decide on the filename. If you are working inside a git repository, the build script should name your file after the branch and commit hash, such asfrost-init-20141228.4d48bab28b6d8f9c43f7b6e36238ef6863b41e90.iso. - If everything went well, attach the ISO file to your VM by methods conventional to your virtualization hypervisor.
- Boot the VM!
Some parts of this project are clearly not original. However, the bash script and
any exemplary portions of the config files are hereby licensed under the MIT License;
see LICENSE.