The newrelic-agent cartridge provides NewRelic agent for PHP applications, to install create your app and run:
rhc add-cartridge http://reflector-getupcloud.getup.io/reflect?github=getupcloud/openshift-newrelic-php-agent --app [APP]
The newrelic agent install the php module and configures the cartridge to push metric to newrelic servers. All you need to do is set the OPENSHIFT_NEWRELIC_LICENSE_KEY environment variable and restart the app.
rhc set-env OPENSHIFT_NEWRELIC_LICENSE_KEY=PUT_YOUR_LICENSE_HERE -a [APP]
rhc app-restart [APP]
This cartridge was designed to work on Getup Cloud Openshift and may not work on your installation, use at your own risk.