From Fedora Project Wiki
VNC access
To setup VNC access to guests through the dashboard:
yum install -y novnc
nova-novncproxy reads some parameters in /etc/nova/nova.conf file. First you need to configure your cloud controller to enable VNC
novncproxy_host = 0.0.0.0 novncproxy_port = 6080
and in the nova compute nodes you need something like this
novncproxy_base_url=http://NOVNCPROXY_FQDN:6080/vnc_auto.html vnc_enabled=true vncserver_listen=COMPUTE_FQDN vncserver_proxyclient_address=COMPUTE_FQDN
You should also make sure that openstack-nova-consoleauth has been started on the controller node:
$ controller> sudo /etc/init.d/openstack-nova-consoleauth restart
After restarting nova services on both nodes the newly created machines will run the qemu-kvm with a parameter -vnc compute_fqdn:display_number. Then after starting the novncproxy and connecting to the dashboard it will discover the host and point to the novncproxy with the appropriate values and connect to the VM.
Note ensure than the iptables entries for VNC ports (5900+DISPLAYNUMBER) are allowed.