How to apply Fedora CoreOS changes without a reboot

Do you want to install Fedora CoreOS packages without having to reboot your entire system in order for the packages to be available? Just run

sudo rpm-ostree ex apply-live

after running your rpm-ostree install commands.

For example:

sudo rpm-ostree install nano
sudo rpm-ostree ex apply-live

Note that this is not completely safe for multiple reasons, not even for seemingly innocuous utility packages like nano:

• As indicated by the ex in the command, the apply-live command is experimental
• It might apply other changes from the new OSTree like automatically installed updated and hence might have effects
• When changing files on a system with productive services running, the services might crash or experience other issues. This might not happen immediately and it might be hard to debug especially in a complex environment. In case you want to safely update your services, it’s almost always best to just reboot into the new OSTree.

Also read our previous post on Why do you have to reboot after rpm-ostree install on Fedora CoreOS? where we explain the technical reasoning behind the reboots.