HOWTO: Automatically set proxies based on network

therealpete · n00b Joined: 02 Feb 2004 Posts: 5

If you have to change locations a lot with your laptop (different companies, different networks, different proxy settings), this tip is for you:

A lot of programs can get their proxy settings from environment variables (http_proxy, ftp_proxy etc.). Amongst them are Gaim, wget, Google Earth, portage and Firefox/Thunderbird with this extension.

To automatically set these variables based on the network, follow these steps (this assumes that you use dhcpcd as your dhcp client):

Create a directory /etc/proxy.d

for each network, you want a proxy set, create a file in this directory with the ip address of the network, like /etc/proxy.d/20.15.50.0

Code:

export RSYNC_PROXY="<yourproxy>:<yourport>"
export http_proxy="<yourproxy>:<yourport>"
export https_proxy="<yourproxy>:<yourport>"
export ftp_proxy="<yourproxy>:<yourport>"
export no_proxy="127.0.0.1,localhost"

create a file /etc/proxy.d/noproxy

Code:

unset RSYNC_PROXY
unset http_proxy
unset ftp_proxy
unset https_proxy
unset no_proxy

create the following script /etc/dhcpc/dhcpcd.exe (it has to have that name, even it is not a binary) and make it executable

Code:

#!/bin/bash

if [ "$2" = "new" ]
then
   source $1;
   if [ -r /etc/proxy.d/$NETWORK ]
      then
         ln -sf /etc/proxy.d/$NETWORK /etc/profile.d/proxy.sh;
      else
         ln -sf /etc/proxy.d/noproxy /etc/profile.d/proxy.sh;
   fi
fi

Now everytime you get a new ip address, your proxy settings change. If you move locations without rebooting, you have to log out and back in to get the new profile.