flatcar-pxe-update-engine

Substitute for the Flatcar update_engine that enables automated reboots on machines booted from PXE.

Instead of downloading the new release, it only signals for a reboot. Flatcar's PXE image does not provide an option to update itself: https://www.flatcar.org/docs/latest/installing/bare-metal/booting-with-ipxe/#update-process

How it works

The update engine periodically checks the release version reported by https://stable.release.flatcar-linux.net/amd64-usr/current/version.txt (or another, configurable URL) and changes the update status to UPDATE_STATUS_UPDATED_NEED_REBOOT when it differs from the current OS release version.

It implements the same DBus interface as the original update_engine, so it works seamlessly with the update_engine_client and reboot orchestrators like locksmithd and [flatcar-linux-update-operator]((https://github.com/kinvolk/flatcar-linux-update-operator).

Deploy

See terraform/ for a Terraform module that provides ignition config for running the flatcar-pxe-update-engine as a systemd service. Refer to the README for instructions.