Guacamole 0.8.3

Overview

Guacamole is a program to control a Linux desktop over the network in a browser.

Sometimes in your Linux life, you need to control your servers in the internet with a graphical user interface. This is tedious when you are behind a corporate firewall blocking ssh requests to the public internet. Typical corporate firewalls only allow proxified client access to port 80, 8080 and 443 in the public internet. One way to go is to use a browser to display a Linux desktop. The solution is not, however, to use VNC for a web browser, as it will be blocked by corporate firewalls. The solution is guacamole.

Quickstart

This will show you

• how to install guacamole 0.8.3 on Ubuntu 10.04
• how to make this configuration survive a reboot
• how to secure transmission with SSL
• how to make the website accessible from behind a firewall (port 80 or 443)

Here's what you do as root user:

• install tomcat and a vncserver

apt-get update
apt-get install tomcat6 tightvncserver

• download the guacamole webapp from http://sourceforge.net/projects/guacamole/files/current/binary/
• deploy it

# mv guacamole-0.8.3.war /var/lib/tomcat6/webapps/

• surf to http://localhost:8080/guacamole-0.8.3. A folder /var/lib/tomcat6/webapps/guacamole-0.8.3 will be created with some content. We will need that later.
• although login is not yet possible your browser will show a login screen like that:

• install some dependencies that the server will need to build with vnc support:

apt-get install libvncserver-dev libpng-dev libcairo-dev

• download guacamole-server from http://sourceforge.net/projects/guacamole/files/current/source/
• unpack it

tar xvzf guacamole-server-0.8.3.tar.gz

• build the server:

cd guacamole-server-0.8.3
./configure && make -j8 && make install

• the following step is ugly; installation and binary do not completely fit so we must do that:

# ln -s /usr/local/lib/libguac.so* /lib
# ln -s /usr/local/lib/libguac-client-vnc.so* /lib/

• now we start the guacamole daemon

# guacd 
guacd[11581]: INFO:  Guacamole proxy daemon (guacd) version 0.8.3
guacd[11581]: INFO:  Successfully bound socket to host ::1, port 4822
guacd[11581]: INFO:  Exiting and passing control to PID 11582

• create a folder for guacamole's configuration:

mkdir /etc/guacamole

• create a file /etc/guacamole/guacamole.properties with the content

# Hostname and port of guacamole proxy
guacd-hostname: localhost
guacd-port:     4822

# Location to read extra .jar's from
lib-directory:  /var/lib/tomcat6/webapps/guacamole-0.8.3/WEB-INF/classes

# Authentication provider class
auth-provider: net.sourceforge.guacamole.net.basic.BasicFileAuthenticationProvider

# Properties used by BasicFileAuthenticationProvider
basic-user-mapping: /etc/guacamole/user-mapping.xml

• create a file /etc/guacamole/user-mapping.xml with the content

<user-mapping>
   <authorize username="user" password="password">
      <protocol>vnc</protocol>
         <param name="hostname">localhost</param>
         <param name="port">5901</param>
         <param name="password">password</param>
    </authorize>
</user-mapping>

• find out your tomcat's user directory:

# cat /etc/passwd|grep tomcat
tomcat6:x:113:116::/usr/share/tomcat6:/bin/false

in this case it is /usr/share/tomcat6

• create a folder .guacamole in your tomcat's user directory:

mkdir /usr/share/tomcat6/.guacamole

• link guacamole.properties into your tomcat's user directories' guacamole folder

ln -s /etc/guacamole/guacamole.properties /usr/share/tomcat6/.guacamole

• start a vnc server, as password set password (the vnc password given in user-mappings.xml)

vncserver

• restart your tomcat server

/etc/init.d/tomcat6 restart

• point your browser to http://localhost:8080/guacamole-0.8.3
• log in as user, password password (the user given in user-mappings.xml)

• next steps: SSL
• next steps: proxypass

TroubleShooting

invalid login

• now the problem is that tomcat does not know where to find the Authentication class:

/var/lib/tomcat6/webapps/guacamole/WEB-INF/classes/net/sourceforge/guacamole/net/basic/BasicFileAuthenticationProvider.class

is not in /etc/guacamole/guacamole.properties

• so add it
• cat /etc/passwd gives me a line

tomcat6:x:113:116::/usr/share/tomcat6:/bin/false

ll /usr/share/tomcat6/.guacamole/
total 8
drwxr-xr-x 2 root root 4096 Nov 26 07:58 ./
drwxr-xr-x 6 root root 4096 Nov 26 07:57 ../
lrwxrwxrwx 1 root root   35 Nov 26 07:58 guacamole.properties -> /etc/guacamole/guacamole.properties

• works now. So the thing is:
  • take care that it is called guacamole and not guacamole-0.8.3 (sure?)
  • make sure the classpath in /etc/guacamole/guacamole.properties is correct, e.g.

# Location to read extra .jar's from
lib-directory:  /var/lib/tomcat6/webapps/guacamole/WEB-INF/classes

Server error

• now I got a server error so I straced guacd:

strace -p 15332

and saw

[pid 20344] open("/usr/lib/x86_64-linux-gnu/libguac-client-vnc.so", O_RDONLY) = -1 ENOENT (No such file or directory)

so the problem is that libguac-client-vnc.so is missing.

• downloaded java version 1.7.45 and compiled guacamole-client using mvn. But there was no *.so* file in it
• so installed libvncserver-dev and rebuild and reinstalled guacamole-server
• and there it is, libguac-client-vnc.so
• now the error message changed from "server error" to "unauthorized"

See also

• http://www.filegott.se/prd/index.php/how-tos/19-how-to-setup-guacamole-in-linux-ubuntu
• http://guac-dev.org/doc/gug/installing-guacamole.html#idp99200