AWS Instance-side script to push custom metrics UsedSpacePercent and UsedMemoryPercent to Cloudwatch

monitoring.py

#!/usr/bin/python

import boto.ec2.cloudwatch
import boto.utils
import commands

if not boto.config.has_section('Boto'):
    boto.config.add_section('Boto')

boto.config.set('Boto', 'proxy', 'proxy.com.au')
boto.config.set('Boto', 'proxy_port', '8080')

cw = boto.ec2.cloudwatch.connect_to_region('ap-southeast-2')
instance_id = boto.utils.get_instance_metadata()['instance-id']

def e(command):
    return commands.getstatusoutput(command)[1]

def postMetric(metric_name, value, dimensions = {}):
    dimensions.update({'InstanceId': instance_id})
    cw.put_metric_data('System/Linux', metric_name, value, unit='Percent', dimensions=dimensions)

def postUsedSpace(path):
    usedpercent = e('df --local '+path+' | grep '+path+' | tr -s \' \' | cut -d \' \' -f 5 | grep -o "[0-9]*"')
    postMetric('UsedSpacePercent', float(usedpercent), {'Path': path})

def postMem():
    memtotal = e('free -m | grep \'Mem\' | tr -s \' \' | cut -d \' \' -f 2')
    memfree = e('free -m | grep \'buffers/cache\' | tr -s \' \' | cut -d \' \' -f 4')
    memused = 100-(float(memfree)*100)/float(memtotal)
    postMetric('UsedMemoryPercent', memused)

postUsedSpace('/')
postUsedSpace('/data')
postMem()