Elastic Beanstalk (AL2) Memory usage

Can anyone point me in the direction of an example on setting up elastic beanstalk memory usage? Before I had an .ebextension file which downloaded the CloudWatchMonitoringScripts zip and it worked fine. However now we are using AL2 I cannot work out how to get the cloudwatch agent to also send the memory usage metrics as well. I'm guessing this has to be done with a new config file and passed to the agent from a platform hook? Thanks