Given you have two cloud-entries defined in the cloud-config. 

image one kubernetes-cluster goes for maintainance then it would be handy if i can do following

1) go to the cloud settings (manage/cloud/)
2) select one cloud
3) go to details
4) check disable [disabled]
5) after disabling the name is crossed out in the cloud list

Effect:
after disabling the k8s-plugin ignores the disabled cloud for scheduling. 

Enhancement: 
Make the state available in groovy-script e.g. for my shared-library