I was looking to build *something* that would possibly benefit several customers that have slow or laggy internet access (ie 2mb broadband or satellite).

The solution needed to be cost effective and unobtrusive.

I did some research and decided to use Squid.

Squid (amongst other things) can cache web objects (such as images and executables), speeding up page load times and download times.

 

Next, I needed some hardware to run Squid on.

Squid can run on Linux and Windows computers, but i ruled out Windows as thats a paid licenced product, thus not cost effective.  I also didnt want to install Squid on a desktop computer, i’d either have to buy a new computer, or re-purpose an old computer – (which can be noisy and unsightly). Both options would also consume significant amounts of energy per year, again not very cost effective.

 

Enter the Raspberry Pi!

I decided on the Raspberry Pi (in this case a Pi3 – Pi 3B+ now available).  It fitted my requirements exactly.  Low inital outlay, low running annual costs, no OS licence fee, small and quiet!

For this guide, you will need:

• Raspberry Pi 2, 3 or 3b+
• 16GB micro SD card minimum (faster the better)
• 5v Micro USB charger
• CAT5e cable connected to the Pi and your Router

• Temporary use of a usb keyboard and mouse
• Temporary use of a HDMI TV / Monitor

Once you have completed the inital network configuration, you can connect to your Raspberry Pi via SSH using Putty (default login for the Raspberry Pi is pi and raspberry).

So, you’ve got your Pi plugged in, and you’ve installed the latest version of Rasperian OS (if you’re new to Linux and the Pi family, download the NOOBs installer!), now its time to get to work.

 

NOTE:  I’m not going to show you how to cache encrypted SSL traffic (port 443). This guide will show you how to cache non encrypted (80) traffic only!

 

Configure a static IP on the Pi.

Remember, unlike Windows, Linux commands are case sensitve!

This guide is based on Raspbian Jessie!

Open a shell window and type:

sudo nano /etc/dhcpcd.conf

Scroll to the end of doc and enter (use a static ip from your subnet, and change the router address to that of your own router).

# Set a static ip address

interface eth0
static ip_address=192.168.5.250/24        
static routers=192.168.5.254
static domain_name_servers=208.67.222.222 208.67.220.220


Press Ctrl + X to quit. Hit Y to save

Reboot the Pi for the changes to take effect

At the shell window type:

sudo reboot

Tweaking the Pi:

Open a new shell window and enter:

sudo raspi-config

Option 1, expand filesystem

Option 9, advanced config. A3 memory split. 8.

Option 3. Boot options – select boot to CLI.

If your running a Raspberry Pi2, you’ll be able to overclock it as well!

Option 5. Make sure SSH is enabled.

Finish / Exit

For the changes to take effect, type:

sudo reboot

At this stage , you will be able to SSH onto your Raspberry Pi using Putty.  This will let you remove the keyboard / mouse + monitor, and let you copy & paste the remaining commands if you want.

Time to update:

Next, we want to update our Raspberry Pi with the latest patches.  Open a new shell window

sudo apt-get update

sudo apt-get upgrade

sudo apt-get dist-upgrade

Hit Y if prompted to reboot.

Now we have a fully patched and up-to-date version of Rasparian; its time to install Squid.

Install Squid:

Enter the following in the shell

sudo apt-get install squid

Configuring Squid:

Backup the original Squid config file:

sudo cp /etc/squid/squid.conf /etc/squid/squidoriginal.conf.bak

Edit the config file:

sudo nano /etc/squid/squid.conf

use Ctrl + W to find each section:

http_access allow localnet = remove the # symbol

Find: acl localnet section

add the following:
acl localnet src YOUR CIDR IP RANGE # Description

ie: 

acl localnet src 192.168.5.0/24 # Home Network

Make sure the ip range/cidr matches your networks range

Find: # dns_v4_first off remove the # symbol and change off to on.

Cache_mem 256 MB

Maximum_object_size 4096 MB

Maximum_object_size_in_memory 8192 KB

Cache_dir ufs /var/spool/squid3 = 8192 (1st variable - this is 8192 MB)

Ctrl + X and Y to save & exit.

Backup your altered squid config file and restart the Squid service:

sudo cp /etc/squid/squid.conf /etc/squid/mysquid.conf.bak

sudo service squid restart

 

Make managing Squid easier with Webmin:

First, install webmins prereqs; open a shell and enter:

sudo apt-get -f install

sudo apt-get -y install apache2 apache2-suexec-custom libnet-ssleay-perl libauthen-pam-perl libio-pty-perl apt-show-versions samba bind9 webalizer locate mysql-server

sudo apt-get install squid-cgi

Enter a secure password for MySQL when prompted.:

From the shell enter these commands in turn:

cd

check your current path should read as /home/pi
pwd

sudo mkdir installed-packages

cd installed-packages

Download the Webmin interface package:
sudo wget http://www.webmin.com/download/deb/webmin-current.deb

Install Webmin:
sudo dpkg -i webmin-current.deb

 

Once Webmin has been installed; open a browser on your pc https://192.168.5.250:10000

Login using the raspberry pi login (default is pi and raspberry).

In webmin; you’ll be able to adjust Squid settings through webmin.  Look under servers; Squid proxy server.

At this stage, its highly likely your webmin config isn’t configured for Squid Pi (should be fine if your following this guide on a Linux ‘Intel / AMD’ PC…

You’ll find SQUID hidden under the In-used modules menu.

Click on the edit config button, change squid3 to squid where highlighted.

Hit save, then hit the orange apply config button. After a minute of so, the Squid services will be restarted and Webmin will work.

If you have an error relating to the cache manager statistic icon, ssh back onto the Pi, use sudo nano to edit the config file, make the required change and save the file. You may need to reboot the pi.

Configuring the client:

Set windows browser proxy: Enter the ip address of the Raspberry Pi (192.168.5.250) and port 3128. Restart browser.

Clear your browser cache and restart the browser.  You should now be using the Squid Proxy server on your Raspberry Pi.

 

Check the cache log:

To check the squid cache logs, open a new shell window and enter:

sudo tail -f /var/log/squid/access.log

Hits are items being pulled from the Squid Cache rather than the internet.

Summary:

If your unlucky enough to have a slow or laggy internet connection,  one possible solution for you is to build and test a Squid proxy server.  However, bear in mind, your mileage may vary as not all objects are cacheable, and certainly any improvement is less noticiable on fast internet connections such as BT infinity.

I performed some “not very scientific” tests using OpenOffice.org.  I found that the download speed of the OpenOffice installer on the first try was 3.9mbs, jumping to 7.9Mb/s after caching once, then maxing out at 9.8Mb/s on the second and subsequent runs (likely a limitation of the Raspberry Pi’s network card – which is limited to 100mbs – UPDATE: Raspberry Pi3B+ has a much faster NIC card).