HAdmin is a Hadoop administration tool, mostly focused on reducing the pain of adding users and queues.
Currently, only Hadoop 2.x using the CapacityScheduler is supported.
Please check out the user manual.
On the off chance that you've stumbled on this project and want to contribute, that's fantastic. You can help in any way you see fit, whether that is refactoring, adding features, writing tests, writing documentation, or testing it out on a cluster.