System-wide proxies in Ubuntu Studio, Xubuntu and XFCE must be set via environment variables

Ubuntu Studio, like Xubuntu, uses the XFCE desktop environment which does not contain a graphical settings tool to set systemwide proxies (unlike the default Ubuntu desktop environment, Unity).

1. Set up the proxy/proxies for most programs

• Open the /etc/environment file with gksudo leafpad (or your favorite editor). This file stores the system-wide variables initialized upon boot.



• Add the following lines, modifying appropriately. You must duplicate in both upper-case and lower-case because (unfortunately) some programs only look for one or the other:

  
  
  

  
  
  http_proxy=http://myproxy.server.com:8080/
  
  https_proxy=http://myproxy.server.com:8080/
  
  ftp_proxy=http://myproxy.server.com:8080/
  
  no_proxy="localhost,127.0.0.1,localaddress,.localdomain.com"
  
  HTTP_PROXY=http://myproxy.server.com:8080/
  
  HTTPS_PROXY=http://myproxy.server.com:8080/
  
  FTP_PROXY=http://myproxy.server.com:8080/
  
  NO_PROXY="localhost,127.0.0.1,localaddress,.localdomain.com"
  
  

2. Then set up proxies for GTK3 programs such as Rhythmbox:

Some newer GTK3 programs such as Rhythmbox ignore the environment variables set above, and rely on Gnome settings instead. To make sure they are covered, open a terminal and paste the below line-by-line, modifying as appropriate:

gsettings set org.gnome.system.proxy mode 'manual' 

gsettings set org.gnome.system.proxy.http host 'myproxy.server.com'

gsettings set org.gnome.system.proxy.http port 8080

3. Finally, set up the proxies for apt-get and Update Manager

• These programs will not obey the environment variables either. Create a file called 95proxies in /etc/apt/apt.conf.d/, and include the following:

  
  
  

  
  
  Acquire::http::proxy "http://myproxy.server.com:8080/";
  
  Acquire::ftp::proxy "ftp://myproxy.server.com:8080/";
  
  Acquire::https::proxy "https://myproxy.server.com:8080/";
  
  

Finally, logout and reboot to make sure the changes take effect.

Sources: 1, 2, 3. See 1 in particular for additional help, including a script to quickly turn on/off the proxies.

Scripts for turning Proxy server on/off:

Disclaimer:: Before proceeding, note that I have tried this on Lubuntu 14.04 and it is IMPORTANT that before you run the mentioned scripts, the file /etc/environment should have only one line in it i.e. '$PATH...' and there should be nothing else in the file, else you might need to modify the script's code. These scripts set and unset the proxy as described above, but they rely upon file truncation and file appending to change /etc/environment and /etc/apt/apt.conf.d/95proxies files. So make sure that:

1) /etc/environment contains only one line i.e. '$PATH:...'. And nothing else.

2) The file /etc/apt/apt.conf.d/95proxies does not exist or does not have anything
important in it.

So! If you want to automate the process of turning proxy on and off without having to type allot. you can make two executable shell scripts proxyon.sh and proxyoff.sh as:

proxyon.sh:

if [ $(id -u) -ne 0 ]; then

  echo "This script must be run as root";

  exit 1;

fi



if [ $# -eq 2 ]

  then



  gsettings set org.gnome.system.proxy mode 'manual' ;

  gsettings set org.gnome.system.proxy.http host '$1';

  gsettings set org.gnome.system.proxy.http port $2;





  grep PATH /etc/environment > lol.t;

  printf 

  "http_proxy=http://$1:$2/



  https_proxy=http://$1:$2/



  ftp_proxy=http://$1:$2/



  no_proxy="localhost,127.0.0.1,localaddress,.localdomain.com"



  HTTP_PROXY=http://$1:$2/



  HTTPS_PROXY=http://$1:$2/



  FTP_PROXY=http://$1:$2/



  NO_PROXY="localhost,127.0.0.1,localaddress,.localdomain.com"

" >> lol.t;



  cat lol.t > /etc/environment;





  printf 

  "Acquire::http::proxy "http://$1:$2/";



  Acquire::ftp::proxy "ftp://$1:$2/";



  Acquire::https::proxy "https://$1:$2/";

" > /etc/apt/apt.conf.d/95proxies;



  rm -rf lol.t;



  else



  printf "Usage $0 <proxy_ip> <proxy_port>

";



fi

proxyoff.sh:

if [ $(id -u) -ne 0 ]; then

  echo "This script must be run as root";

  exit 1;

fi



gsettings set org.gnome.system.proxy mode 'none' ;



grep PATH /etc/environment > lol.t;

cat lol.t > /etc/environment;



printf "" > /etc/apt/apt.conf.d/95proxies;



rm -rf lol.t;

How to use: Once you have made these scripts, make them executable, you may keep them anywhere you like. To turn on proxy all you have to do is go to the directory containing the 'proxyon.sh' script and then you need to type sudo ./proxyon.sh {host} {port}. As an example consider this:

 $ sudo ./proxyon.sh 10.2.20.17 8080

 OR

 $ sudo ./proxyon.sh myproxy.server.com 8080

Where '10.2.20.17' is the proxy server's IP - you can also type something like myproxy.server.com - and '8080' is the port. After that just log out and login to your account, to make sure that everything is set. You can start using the internet or whatever then. And when you want to turn the proxy off, go to the directory containing 'proxyoff.sh' and type:

 $ sudo ./proxyoff.sh

This will unset all of your proxies. Now logout and login again to switch to normal mode.