Table of Contents
After installing Guacamole, it will be minimally configured to use the default
authentication, which reads all users and connections from a single, monolithic
user-mapping.xml file. You can modify this configuration if you
need to use a different authentication module (such as the MySQL authentication, which is
discussed in a separate chapter) or if you need to veer from the defaults.
Guacamole's configuration consists of two main pieces: a directory
referred to as GUACAMOLE_HOME, which is the primary
search location for configuration files, and
guacamole.properties, the main configuration
file used by Guacamole and its extensions.
Guacamole reads files from its own configuration directory by default, resorting to the classpath only when this directory cannot be found. When locating this directory, Guacamole will try, in order:
-
The directory specified within the system property guacamole.home.
-
The directory specified within the environment variable
GUACAMOLE_HOME. -
The directory
.guacamole, located within the home directory of the user running the servlet container.
This directory will be referred to as
GUACAMOLE_HOME elsewhere in the
documentation.
Guacamole uses GUACAMOLE_HOME as the primary
search location for configuration file like
guacamole.properties.
The Guacamole web application uses one main configuration file called
guacamole.properties. This file is the common location for all
configuration properties read by Guacamole or any extension of Guacamole, including
authentication providers.
In previous releases, this file had to be in the classpath of your servlet container.
Now, the location of guacamole.properties can be explicitly defined
with environment variables or system properties, and the classpath is only used as a
last resort. When searching for guacamole.properties, Guacamole
will check, in order:
-
Within
GUACAMOLE_HOME, as defined above. -
The classpath of the servlet container.
At the bare minimum, the guacamole.properties file provides five
basic properties:
guacd-host-
The host the Guacamole proxy daemon (guacd) is listening on. This is most likely localhost.
guacd-port-
The port the Guacamole proxy daemon (guacd) is listening on. This is port 4822 by default.
guacd-ssl-
If set to "true", requires SSL/TLS encryption between the web application and guacd. This property is not required. By default, communication between the web application and guacd will be unencrypted.
Note that if you enable this option, you must also configure guacd to use SSL via command line options. These options are documented in the manpage of guacd. You will need an SSL certificate and private key.
auth-provider-
The authentication provider to use when authenticating. Normally, this will be set to
BasicFileAuthenticationProviderwhich is the default authentication provider provided with Guacamole. lib-directory-
The directory to load extensions to Guacamole from. If you wish to use a custom authentication provider or custom hooks, the
.jarfile and all dependencies must be placed in the directory specified here. event-listeners-
A comma-delimited list of event listeners which should be loaded and installed such that they are informed of Guacamole-related events. These classes must be in the classpath, preferably by having their corresponding
.jarfiles placed within the directory specified by the lib-directory property.
Example 3.1. Minimal guacamole.properties
# Hostname and port of guacamole proxy
guacd-hostname: localhost
guacd-port: 4822
# Location to read extra .jar's from
lib-directory: /var/lib/guacamole/classpath
# Authentication provider class
auth-provider: net.sourceforge.guacamole.net.basic.BasicFileAuthenticationProvider
# Properties used by BasicFileAuthenticationProvider
basic-user-mapping: /etc/guacamole/user-mapping.xml
Guacamole's default authentication module is simple and consists
of a mapping of usernames to configurations. This authentication
module comes with Guacamole and simply reads usernames and passwords
from an XML file. If you wish to use this authentication mechanism,
you must ensure the auth-provider property is
set to the fully-qualified name of
BasicFileAuthenticationProvider[1]This is the case within the example
guacamole.properties file shown above, and
in the guacamole.properties file included with
Guacamole. Unless you have already tried another authentication
module, you will not need to edit this value yourself if you are
using the configuration files that come with Guacamole.
There are other authentication modules available. The Guacamole project now provides a MySQL-backed authentication module with extra features (like the ability to manage connections and users from the web interface), and other authentication modules can be created using the extension API provided along with the Guacamole web application, guacamole-ext.
The default authentication provider used by Guacamole reads
all username, password, and configuration information from a
file called the "user mapping" (typically named
user-mapping.xml). An example of this
file is included with Guacamole, and looks something like
this:
<user-mapping>
<!-- Per-user authentication and config information -->
<authorize username="USERNAME" password="PASSWORD">
<protocol>vnc</protocol>
<param name="hostname">localhost</param>
<param name="port">5900</param>
<param name="password">VNCPASS</param>
</authorize>
<!-- Another user, but using md5 to hash the password
(example below uses the md5 hash of "PASSWORD") -->
<authorize
username="USERNAME2"
password="319f4d26e3c536b5dd871bb2c52e3178"
encoding="md5">
<!-- First authorized connection -->
<connection name="localhost">
<protocol>vnc</protocol>
<param name="hostname">localhost</param>
<param name="port">5901</param>
<param name="password">VNCPASS</param>
</connection>
<!-- Second authorized connection -->
<connection name="otherhost">
<protocol>vnc</protocol>
<param name="hostname">otherhost</param>
<param name="port">5900</param>
<param name="password">VNCPASS</param>
</connection>
</authorize>
</user-mapping>
Each user is specified with a corresponding
<authorize> tag. This tag contains all
authorized connections for that user, each denoted with a
<connection> tag. Each
<connection> tag contains a corresponding
protocol and set of protocol-specific parameters, specified with
the <protocol> and <param> tags
respectively.
When using
BasicFileAuthenticationProvider,
username/password pairs are specified with
<authorize> tags, which each have a
username and password
attribute. Each <authorize> tag authorizes a
specific username/password pair to access all connections
within the tag:
<authorize username="USER" password="PASS"> ... </authorize>
In the example above, the password would be listed in plaintext. If you don't want to do this, you can also specify your password hashed with MD5:
<authorize username="USER" password="319f4d26e3c536b5dd871bb2c52e3178" encoding="md5"> ... </authorize>
After modifying user-mapping.xml, the file will be automatically reread by Guacamole, and your changes will take effect immediately. The newly-added user will be able to log in - no restart of the servlet container is needed.
To specify a connection within an
<authorize> tag, you can either list a
single protocol and set of parameters (specified with a
<protocol> tag and any number of
<param> tags), in which case that user
will have access to only one connection named "DEFAULT", or
you can specify one or more connections with one or more
<connection> tags, each of which can be
named and contains a <protocol> tag and any
number of <param> tags.
The VNC protocol is the simplest and first protocol supported by Guacamole. Although generally not as fast as RDP, many VNC servers are adequate, and VNC over Guacamole tends to be faster than VNC by itself due to decreased bandwidth usage.
VNC support for Guacamole is provided by the libguac-client-vnc library, installed by default.
Table 3.1. VNC configuration parameters
If you are using the default authentication built into Guacamole, and you wish to
grant access to a VNC connection to a particular user, you need to locate the
<authorize> section for that user within your
user-mapping.xml, and add a section like the following
within it:
<connection name="Unique Name"> <protocol>vnc</protocol> <param name="hostname">localhost</param> <param name="port">5901</param> </connection>
If added exactly as above, a new connection named "Unique
Name" will be available to the user associated with the
<authorize> section containing it. The connection will use VNC
to connect to localhost at port
5901. Naturally, you will want to change some or all
of these values.
If your VNC server requires a password, or you wish to specify other configuration
parameters (to reduce the color depth, for example), you will need to add additional
<param> tags accordingly.
Other authentication methods will provide documentation describing how to configure new connections. If the authentication method in use fully implements the features of Guacamole 0.8.0, you will be able to add a new VNC connection easily and intuitively using the administration interface built into Guacamole. You will not need to edit configuration files.
The choice of VNC server can make a big difference when it comes to performance, especially over slower networks. While many systems provide VNC access by default, using this is often not the fastest method.
RealVNC, and its derivative TigerVNC, perform quite well. In our testing, they perform the best with Guacamole. If you are okay with having a desktop that can only be accessed via VNC, one of these is likely your best choice. Both optimize window movement and (depending on the application) scrolling, giving a very responsive user experience.
TightVNC is widely-available and performs generally as well as RealVNC or TigerVNC. If you wish to use TightVNC with Guacamole, performance should be just fine, but we highly recommend disabling its JPEG encoding. This is because images transmitted to Guacamole are always encoded losslessly as PNG images. When this operation is performed on a JPEG image, the artifacts present from JPEG's lossy compression reduce the compressibility of the image for PNG, thus leading to a slower experience overall than if JPEG was simply not used to begin with.
The main benefit of using x11vnc is that it allows you to continue using your desktop normally, while simultaneously exposing control of your desktop via VNC. Performance of x11vnc is comparable to RealVNC, TigerVNC, and TightVNC. If you need to use your desktop locally as well as via VNC, you will likely be quite happy with x11vnc.
vino is the VNC server that comes with the Gnome desktop environment, and is enabled if you enable "desktop sharing" via the system preferences available within Gnome. If you need to share your local desktop, we recommend using x11vnc rather vino, as it has proven more performant and feature-complete in our testing. If you don't need to share a local desktop but simply need an environment you can access remotely, using a VNC server like RealVNC, TigerVNC, or TightVNC is a better choice.
QEMU (and thus KVM) expose the displays of virtual machines using VNC. If you need to see the virtual monitor of your virtual machine, using this VNC connection is really your only choice. As the VNC server built into QEMU cannot be aware of higher-level operations like window movement, resizing, or scrolling, those operations will tend to be sent suboptimally, and will not be as fast as a VNC server running within the virtual machine.
If you wish to use a virtual machine for desktop access, we recommend installing a native VNC server inside the virtual machine after the virtual machine is set up. This will give a more responsive desktop.
The RDP protocol is more complicated than VNC and was the second protocol officially supported by Guacamole. RDP tends to be faster than VNC due to the use of caching, which Guacamole does take advantage of.
RDP support for Guacamole is provided by the libguac-client-rdp library, which depends on a recent version of FreeRDP (version 1.0 or higher). If your distribution does not have a recent enough version of FreeRDP, the Guacamole project will not build a libguac-client-rdp package for you. You will need to build and install a recent version of FreeRDP, and then build and install libguac-client-rdp from source.
Table 3.2. RDP configuration parameters
If you are using the default authentication built into Guacamole, and you wish to
grant access to a RDP connection to a particular user, you need to locate the
<authorize> section for that user within your
user-mapping.xml, and add a section like the following
within it:
<connection name="Unique Name"> <protocol>rdp</protocol> <param name="hostname">localhost</param> <param name="port">3389</param> </connection>
If added exactly as above, a new connection named "Unique
Name" will be available to the user associated with the
<authorize> section containing it. The connection will use RDP
to connect to localhost at port
3389. Naturally, you will want to change some or all
of these values.
If you want to login automatically rather than receive a login prompt upon
connecting, you can specify a username and password with additional
<param> tags. Other options are available for controlling the
color depth, size of the screen, etc.
Other authentication methods will provide documentation describing how to configure new connections. If the authentication method in use fully implements the features of Guacamole 0.8.0, you will be able to add a new RDP connection easily and intuitively using the administration interface built into Guacamole. You will not need to edit configuration files.
Unlike VNC or RDP, SSH is a text protocol. Its implementation in Guacamole is actually a combination of a terminal emulator and SSH client, because the SSH protocol isn't inherently graphical. Guacamole's SSH support emulates a terminal on the server side, and draws the screen of this terminal remotely on the client.
SSH support for Guacamole is provided by the libguac-client-ssh library, which depends on libssh.
Table 3.3. SSH configuration parameters
If you are using the default authentication built into Guacamole, and you wish to
grant access to a SSH connection to a particular user, you need to locate the
<authorize> section for that user within your
user-mapping.xml, and add a section like the following
within it:
<connection name="Unique Name"> <protocol>ssh</protocol> <param name="hostname">localhost</param> <param name="port">22</param> </connection>
If added exactly as above, a new connection named "Unique
Name" will be available to the user associated with the
<authorize> section containing it. The connection will use SSH
to connect to localhost at port
22. Naturally, you will want to change some or all of
these values.
If you want to login automatically rather than receive a login prompt upon
connecting, you can specify a username and password with additional
<param> tags. Other options are available for controlling the
font.
Other authentication methods will provide documentation describing how to configure new connections.