Managing upgrades

Right now, bootc is a quite simple tool that is designed to do just a few things well. One of those is transactionally fetching new operating system updates from a registry and booting into them, while supporting rollback.

The bootc upgrade verb

This will query the registry and queue an updated container image for the next boot.

This is backed today by ostree, implementing an A/B style upgrade system. Changes to the base image are staged, and the running system is not changed by default.

Use bootc upgrade --apply to auto-apply if there are queued changes.

There is also an opinionated bootc-fetch-apply-updates.timer and corresponding service available in upstream for operating systems and distributions to enable.

Man page: bootc-upgrade.

Changing the container image source

Another useful pattern to implement can be to use a management agent to invoke bootc switch (or declaratively via bootc edit) to implement e.g. blue/green deployments, where some hosts are rolled onto a new image independently of others.

bootc switch

bootc switch has the same effect as bootc upgrade; there is no semantic difference between the two other than changing the container image being tracked.

This will preserve existing state in /etc and /var - for example, host SSH keys and home directories.

Man page: bootc-switch.


There is a bootc rollback verb, and associated declarative interface accessible to tools via bootc edit. This will swap the bootloader ordering to the previous boot entry.

Man page: bootc-rollback.