[fleetlock] is an implementation of the Zincati FleetLock reboot
coordination protocol. It only works for machines that are Kubernetes
nodes, but it does enable safe rolling updates for those machines.
Specifically, when a node acquires a lock (backed by a Kubernetes
Lease), it cordons that node and evicts pods from it. After the node
has rebooted into the new version of Fedora CoreOS, it uncordons the
node and releases the lock.
[fleetlock]: https://github.com/poseidon/fleetlock
Dustin