To provide a remote console or remote desktop access to guest virtual machines, use VNC or SPICE HTML5 through either the OpenStack dashboard or the command line. Best practice is to select one or the other to run.
Both client proxies leverage a shared service to manage token
authentication called nova-consoleauth
. This service must be running for
either proxy to work. Many proxies of either type can be run against a
single nova-consoleauth
service in a cluster configuration.
Do not confuse the nova-consoleauth
shared service with
nova-console
, which is a XenAPI-specific service that most recent
VNC proxy architectures do not use.
OpenStack Compute supports VNC consoles to guests. The VNC protocol is fairly limited, lacking support for multiple monitors, bi-directional audio, reliable cut-and-paste, video streaming and more. SPICE is a new protocol that aims to address the limitations in VNC and provide good remote desktop support.
SPICE support in OpenStack Compute shares a similar architecture to the
VNC implementation. The OpenStack dashboard uses a SPICE-HTML5 widget in
its console tab that communicates to the nova-spicehtml5proxy
service by
using SPICE-over-websockets. The nova-spicehtml5proxy
service
communicates directly with the hypervisor process by using SPICE.
VNC must be explicitly disabled to get access to the SPICE console. Set
the vnc_enabled
option to False
in the [DEFAULT]
section to
disable the VNC console.
Use the following options to configure SPICE as the console for OpenStack Compute:
[spice]
agent_enabled = False
enabled = True
html5proxy_base_url = http://IP_ADDRESS:6082/spice_auto.html
html5proxy_host = 0.0.0.0
html5proxy_port = 6082
keymap = en-us
server_listen = 127.0.0.1
server_proxyclient_address = 127.0.0.1
Replace IP_ADDRESS
with the management interface IP address
of the controller or the VIP.
The VNC proxy is an OpenStack component that enables compute service users to access their instances through VNC clients.
Note
The web proxy console URLs do not support the websocket protocol scheme (ws://) on python versions less than 2.7.4.
The VNC console connection works as follows:
A user connects to the API and gets an access_url
such as,
http://ip:port/?token=xyz
.
The user pastes the URL in a browser or uses it as a client parameter.
The browser or client connects to the proxy.
The proxy talks to nova-consoleauth
to authorize the token for the
user, and maps the token to the private host and port of the VNC
server for an instance.
The compute host specifies the address that the proxy should use to
connect through the nova.conf
file option,
vncserver_proxyclient_address
. In this way, the VNC proxy works
as a bridge between the public network and private host network.
The proxy initiates the connection to VNC server and continues to proxy until the session ends.
The proxy also tunnels the VNC protocol over WebSockets so that the
noVNC
client can talk to VNC servers. In general, the VNC proxy:
To customize the VNC console, use the following configuration options in
your nova.conf
file:
Note
To support live migration,
you cannot specify a specific IP address for vncserver_listen
,
because that IP address does not exist on the destination host.
Configuration option = Default value | Description |
---|---|
[DEFAULT] | |
daemon = False |
(BoolOpt) Become a daemon (background process) |
key = None |
(StrOpt) SSL key file (if separate from cert) |
novncproxy_host = 0.0.0.0 |
(StrOpt) Host on which to listen for incoming requests |
novncproxy_port = 6080 |
(IntOpt) Port on which to listen for incoming requests |
record = False |
(BoolOpt) Record sessions to FILE.[session_number] |
source_is_ipv6 = False |
(BoolOpt) Source is ipv6 |
ssl_only = False |
(BoolOpt) Disallow non-encrypted connections |
web = /usr/share/spice-html5 |
(StrOpt) Run webserver on same port. Serve files from DIR. |
[vmware] | |
vnc_port = 5900 |
(IntOpt) VNC starting port |
vnc_port_total = 10000 |
vnc_port_total = 10000 |
[vnc] | |
enabled = True | (BoolOpt) Enable VNC related features |
novncproxy_base_url = http://127.0.0.1:6080/vnc_auto.html | (StrOpt) Location of VNC console proxy, in the form “http://127.0.0.1:6080/vnc_auto.html“ |
vncserver_listen = 127.0.0.1 | (StrOpt) IP address on which instance vncservers should listen |
vncserver_proxyclient_address = 127.0.0.1 | (StrOpt) The address to which proxy clients (like nova-xvpvncproxy) should connect |
xvpvncproxy_base_url = http://127.0.0.1:6081/console | (StrOpt) Location of nova xvp VNC console proxy, in the form “http://127.0.0.1:6081/console“ |
Note
vncserver_proxyclient_address
defaults to 127.0.0.1
,
which is the address of the compute host that Compute instructs
proxies to use when connecting to instance servers.169.254.0.1.
dom0
management IP
on the same network as the proxies.A typical deployment has the following components:
nova-consoleauth
process. Typically runs on the controller host.nova-novncproxy
services. Supports browser-based noVNC
clients. For simple deployments, this service typically runs on the
same machine as nova-api
because it operates as a proxy between the
public network and the private compute host network.nova-xvpvncproxy
services. Supports the special Java
client discussed here. For simple deployments, this service typically
runs on the same machine as nova-api
because it acts as a proxy
between the public network and the private compute host network.You must install the noVNC package, which contains the nova-novncproxy
service. As root, run the following command:
# apt-get install nova-novncproxy
The service starts automatically on installation.
To restart the service, run:
# service nova-novncproxy restart
The configuration option parameter should point to your nova.conf
file, which includes the message queue server address and credentials.
By default, nova-novncproxy
binds on 0.0.0.0:6080
.
To connect the service to your Compute deployment, add the following
configuration options to your nova.conf
file:
vncserver_listen=0.0.0.0
Specifies the address on which the VNC service should bind. Make sure it is assigned one of the compute node interfaces. This address is the one used by your domain file.
<graphics type="vnc" autoport="yes" keymap="en-us" listen="0.0.0.0"/>
Note
To use live migration, use the 0.0.0.0 address.
vncserver_proxyclient_address=127.0.0.1
The address of the compute host that Compute instructs proxies to use
when connecting to instance vncservers
.
Q: What is the difference between ``nova-xvpvncproxy`` and ``nova-novncproxy``?
A: nova-xvpvncproxy
, which ships with OpenStack Compute, is a
proxy that supports a simple Java client. nova-novncproxy uses noVNC
to provide VNC support through a web browser.
Q: I want VNC support in the OpenStack dashboard. What services do I need?
A: You need nova-novncproxy
, nova-consoleauth
, and correctly
configured compute hosts.
Q: When I use ``nova get-vnc-console`` or click on the VNC tab of the OpenStack dashboard, it hangs. Why?
A: Make sure you are running nova-consoleauth
(in addition to
nova-novncproxy
). The proxies rely on nova-consoleauth
to validate
tokens, and waits for a reply from them until a timeout is reached.
Q: My VNC proxy worked fine during my all-in-one test, but now it doesn’t work on multi host. Why?
A: The default options work for an all-in-one install, but changes must be made on your compute hosts once you start to build a cluster. As an example, suppose you have two servers:
PROXYSERVER (public_ip=172.24.1.1, management_ip=192.168.1.1)
COMPUTESERVER (management_ip=192.168.1.2)
Your nova-compute
configuration file must set the following values:
# These flags help construct a connection data structure
vncserver_proxyclient_address=192.168.1.2
novncproxy_base_url=http://172.24.1.1:6080/vnc_auto.html
xvpvncproxy_base_url=http://172.24.1.1:6081/console
# This is the address where the underlying vncserver (not the proxy)
# will listen for connections.
vncserver_listen=192.168.1.2
Note
novncproxy_base_url
and xvpvncproxy_base_url
use a public
IP; this is the URL that is ultimately returned to clients, which
generally do not have access to your private network. Your
PROXYSERVER must be able to reach vncserver_proxyclient_address
,
because that is the address over which the VNC connection is proxied.
Q: My noVNC does not work with recent versions of web browsers. Why?
A: Make sure you have installed python-numpy
, which is required
to support a newer version of the WebSocket protocol (HyBi-07+).
Q: How do I adjust the dimensions of the VNC window image in the OpenStack dashboard?
A: These values are hard-coded in a Django HTML template. To alter
them, edit the _detail_vnc.html
template file. The location of
this file varies based on Linux distribution. On Ubuntu 14.04, the
file is at
/usr/share/pyshared/horizon/dashboards/nova/instances/templates/instances/_detail_vnc.html
.
Modify the width
and height
options, as follows:
<iframe src="{{ vnc_url }}" width="720" height="430"></iframe>
Q: My noVNC connections failed with ValidationError: Origin header protocol does not match. Why?
A: Make sure the base_url
match your TLS setting. If you are
using https console connections, make sure that the value of
novncproxy_base_url
is set explicitly where the nova-novncproxy
service is running.
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