OpenStack offers two types of console support, VNC support and SPICE.
The VNC protocol is fairly limited, lacking support for multiple monitors,
bi-directional audio, reliable cut+paste, video streaming and more.
SPICE is a new protocol which aims to address all the limitations in VNC,
to provide good remote desktop support.

The Controller will have both the proxy for vnc and for spice html5
running. The nova-spicehtml5proxy service communicates directly with
the hypervisor process using SPICE.

OpenStack's Dashboard uses a SPICE HTML5 widget in its console tab 
to communicate with the nova-spicehtml5proxy service. Since both proxies
are running, the Dashboard will automatically attempt to connect to
whichever console is provided by the compute node.

Another way to access the spice console is from the controller,
run the following command:

	nova get-spice-console myinstance spice-html5

This will give you an URL which will directly give you access to the console
(instead of from Horizon).

The enable or disable VNC/SPICE, on the compute node, modify
/etc/nova/nova.conf.

Options for configuring SPICE as the console for OpenStack Compute can be
 found below.

---------------------------------------------------------------------------------
 Configuration option=Default value	(Type) Description

 agent_enabled=True			(BoolOpt)enable spice guest agent support

 enabled=False				(BoolOpt)enable spice related features

 html5proxy_base_url=http://127.0.0.1:6080/spice_auto.html
 					(StrOpt)location of spice html5 
					console proxy, in the form 
					"http://127.0.0.1:6080/spice_auto.html"

 keymap=en-us				(StrOpt)keymap for spice

 server_listen=127.0.0.1		(StrOpt)IP address on which instance
 					spice
 server should listen

 server_proxyclient_address=127.0.0.1	(StrOpt)the address to which proxy
 					clients (like nova-spicehtml5proxy) 
					should connect
---------------------------------------------------------------------------------

Combinations/behaviour from Compute:

1. VNC will be provided

vnc_enabled=True
enabled=True
agent_enabled=True

2. SPICE will be provided

vnc_enabled=False
enabled=True
agent_enabled=True

3. VNC will be provided

vnc_enabled=True
enabled=False
agent_enabled=False

4. No console will be provided

vnc_enabled=False
enabled=False
agent_enabled=False

After nova.conf is changed on the compute node, restart nova-compute
service. If an instance was running beforehand, it will be necessary to
restart (reboot, soft or hard) the instance to get the new console.