System Initialization for Flatcar Container Linux
Flatcar uses systemd for init and process management. This repo is
divided into three collections of files:
- configs: Customized daemon configuration files, usually installed into
/etcbut really the sky is the limit there. - scripts: Helper scripts for init and service startup. These are generally to
be used as systemd oneshot services and installed into/usr/lib/flatcar. - systemd: Unit files for mount points, our helper scripts, or other services
that don't install their own unit files.
The coreos-base/coreos-init ebuild handles the install process.
Important Steps
A few notes on things that must happen which are unique to Flatcar.
- resize btrfs: Support easy VM growth by checking if there is unused space at
the end of the disk and expanding the filesystem to use it. - mount
/: This directory can be completely empty. - initialize
/: The/partition can be completely formatted by the
user. Run systemd-tmpfiles to set everything up into a known state. - mount
/usr: The entire distro lives in this directory. - mount
/oem: If an OEM is available on disk make sure it gets mounted here. - generate ssh keys: The stock sshd units do not handle this so we need to.