Prerequisites need to be installed if you're doing this on a brand new, empty VM. See:
http://docs.openstack.org/developer/horizon/quickstart.html
Install Horizon (note: this is in developer mode) first:
% git clone https://github.com/openstack/horizon.git
% cd horizon
% cp openstack_dashboard/local/local_settings.py.example openstack_dashboard/local/local_settings.py
Edit openstack_dashboard/local/local_settings.py
to set OPENSTACK_HOST
to the IP of your keystone server.
% ./run_tests.sh --runserver
% ^C
This will install Horizon's dependencies (in .venv) and bring up Horizon in foreground, ^C kills it. Verify it's worked by logging in as admin at http://<IP address>:8000/
where the IP address is whatever host you're currently on.
Now, to install the ironic ui:
% source .venv/bin/activate
% cd ..
% git clone https://git.openstack.org/openstack/ironic-ui
% cd ironic-ui
% pip install -e .
% cp ironic_ui/enabled/_2200_ironic.py ../horizon/openstack_dashboard/local/enabled
% cd ../horizon
% ./run_tests.sh --runserver
The Ironic Bare Metal Provisioning plugin should now be visible in the Horizon navigation in the Admin section.