Debian 8 - Install MongoDB PHP Driver

Install pear and the php dev tools necessary for compiliation if you haven't already.

sudo apt-get install php5-dev php5-cli php-pear -y

Install the mongo driver

sudo pecl install mongo

This will ask you inf you want to install Enterprise authentcation and the default is 'no';

Add the extension to the php.ini files by running the script below with BASH. This assumes you are using apache.

#!/bin/bash
SEARCH='; If you wish to have an extension loaded automatically, use the following'
REPLACE='extension=mongo.so\n; If you wish to have an extension loaded automatically, use the following'
FILEPATH="/etc/php5/apache2/php.ini"
CLI_FILEPATH="/etc/php5/cli/php.ini"
sudo sed -i "s:$SEARCH:$REPLACE:" $FILEPATH
sudo sed -i "s:$SEARCH:$REPLACE:" $CLI_FILEPATH

# Restart Apache to take effect
sudo service apache2 restart

At the time of writing this tutorial using a Debian 8 box with PHP 5.6, this resulted installing version 1.6.11

Check Driver Version

php --ri mongo | grep Version