fuse host cordon

Mark a host unschedulable

fuse host cordon <id>

No flags beyond the globals. Marks the host unschedulable: the scheduler stops placing new environments there. Existing environments already running on the host are untouched, cordoning is not a drain.

The standard move before host maintenance:

fuse host cordon prod-east-1
# ... perform maintenance, existing VMs keep running ...
fuse host uncordon prod-east-1

See fuse host uncordon to reverse it.