• Red Hat/CentOS:

sudo rpm -Uvh http://yum.newrelic.com/pub/newrelic/el5/x86_64/newrelic-repo-5-3.noarch.rpm
yum install newrelic-php5 -y
sudo newrelic-install install

• Debian/Ubuntu:

echo 'deb http://apt.newrelic.com/debian/ newrelic non-free' | sudo tee /etc/apt/sources.list.d/newrelic.list
wget -O- https://download.newrelic.com/548C16BF.gpg | sudo apt-key add -
sudo apt-get update
sudo apt-get install newrelic-php5 -y
sudo newrelic-install install

Configure your application name and New Relic license key. The installation process prompts for your application name and license key. Your license key appears in the account information section of Account settings.

systemctl restart lsws
killall lsphp

Visit any PHP page to generate some traffic.

Attempt to connect to the application on the New Relic account page, and it should be working.