Use k8 optimistic locking to implement. See:

http://blog.kubernetes.io/2016/01/simple-leader-election-with-Kubernetes.html

And heres some go code which does something similar:
https://github.com/fabric8io/kansible/blob/2413588faed5f66aea28b8d3a042c3149726e0be/ansible/ansible.go#L197-L279

This basically means that all master endpoints in the JVM will share a single lock that is associated with the k8 replication controller.