I loved DCOS demos on Azure. No I wonder - having a private OpenStack based clud how to install Mesos with that UI manually? Is it possible or it is a part of DCOS they do not provide as OpenSource product?
The DCOS Dashboard is pretty cool :-). Currently it is just available via the DCOS beta on AWS and Azure. There will be on prem packages later on as well, potentially even a community edition. Feel free to contact/follow Mesosphere for updates.
Until then you can use the standard Mesos, Marathon, and Chronos UIs as Alex pointed out.