SNO provision from Hetzner rescue

WARNING: This is neither supported nor endorsed by Red Hat or Hetzner. It is experimental and not intended for production use. Use it under your own risk.

This is a simple script meant to be run from Hetzner Rescue System to be able to install OpenShift from the assisted installer.

What the script does:

• Installs kexec-tools into the rescue system
• It downloads the indicated iPXE script, provided by assisted installer for the discovery phase (as an alternative to the discovery ISO)
• Then it downloads the kernel and the initrd from the URLs on the iPXE script.
• Last, it kexecs into the downloaded kernel and initrd with the kernel parameters provided by the iPXE script

More warnings:

• This script assumes that you have previously wiped the hard drives of the node.
• You must feed assisted installer with the right network configuration before generating the iPXE script. Using nmstate file is recommended.
• This worked in the server where I could test it. However, as kexec does not perform the hardware initialization in the very same way than a regular boot, it might not work as expected depending on the server hardware (or just on how lucky you are).

Usage

./hetzner-sno-provision-host.sh <iPXE script URL>

Where:

• <iPXE script URL> is the download URL for the iPXE script provided by assisted installer.