---------- Information ------------
Polipo Offline Mode Auto Toggle
By: Scott Martin
Created: May 19, 2011
Description: Automatically enables/disables the proxyOffline setting in polipo on network disconnect/connect, respectively. 

---------- Requirements ----------
- Polipo (package "polipo" in Ubuntu 11.04 repository)
- Notify-Send (package "libnotify-bin" in Ubuntu 11.04 repo)
- cURL (package "curl" in 11.04)

Here's the installation command:
sudo apt-get install polipo libnotify-bin curl

---------- Installation ----------
After installing the requirements (and with the polipo daemon started - it should do this automatically on install), configure your browser of choice to use the address localhost:8123 as an HTTP proxy. 

This pipes all website requests through polipo, which caches each webpage as it comes through.

Now copy the script to the network manager dispatcher so that it runs automatically on network connect/disconnect:
sudo cp ./99polipo-online /etc/NetworkManager/dispatcher.d/

Be sure the script is set as executable. Try it out, and see if it works!


------ Configuration Changes -----
The following are a few configuration changes that may be useful when setting up a cache server.

Remember to restart the polipo daemon after making the changes:
sudo service polipo restart

-------- Viewing the Cache -------
To view the cache without trying to navigate to a specific site, and to see a list of known hosts, make sure the following is set in /etc/polipo/config.
(WARNING!!! this is a potential security risk - it allows ANYONE who connects to the web interface the ability to see EVERYONE's browsing history)
disableIndexing = false
disableServersList = false

---------- Blacklisting ----------
Also, polipo can be told to not cache certain websites (e.g. ad links, hit counters, etc.). To do this, edit the 'forbidden' config file:
gksu gedit /etc/polipo/forbidden

And remove the pound signs from the domains you want to ignore. If you have specific domains, add them here! Also supports regexing.

-------- Allowing Access ---------
To allow a certain list of IP addresses to access cached pages, modify the allowedClients section and add the IP range:
allowedClients = 127.0.0.1, 192.168.42.0/24