Updating from CoreOS Container Linux

Mon, 01 Jan 0001 00:00:00 +0000

If you already have CoreOS Container Linux clusters and can’t or don’t want to freshly install Flatcar Container Linux, you can update to Flatcar Container Linux directly from CoreOS Container Linux by performing the following steps.

NOTE: General differences when migrating from CoreOS Container Linux also apply.

The migration script

The update-to-flatcar.sh script does all required steps for you:

# To be run on the node via SSH
core@host ~ $ wget https://raw.githubusercontent.com/flatcar/flatcar-docs/main/update-to-flatcar.sh
core@host ~ $ less update-to-flatcar.sh # Double check the content of the script
core@host ~ $ chmod +x update-to-flatcar.sh
core@host ~ $ ./update-to-flatcar.sh
[…]
Done, please reboot now
core@host ~ $ sudo systemctl reboot

If it fails due to SSL connection issues from outdated certificates, you can also download the update payload of the latest Stable release through plain HTTP and use the flatcar-update script instead:

Migration from CoreOS Container Linux on Flatcar Container Linux

Updating from CoreOS Container Linux

The migration script