With the default value for nimbus.seeds (["localhost"]) Storm UI may list one "Offline" nimbus for localhost, and another as "Leader" for the resolved machine name.
Steps to reproduce (assumes ZK is running; all on local machine):
1. Clean install of 1.0.0-SNAPSHOT (do not modify storm.yaml)
2. Start nimbus
3. Start supervisor
4. Start ui
5. Navigate to http://localhost:8080
A workaround is to modify storm.yaml and replace "localhost" with the hostname of the machine in nimbus.seeds.
While trivial to correct, this may confuse users. One approach is to simply document this behavior.