push docker data used to cloudwatch custom metric

docker_data_to_cw.py

#!/usr/bin/env python

import subprocess
import json
import boto3
import urllib2
instanceid = urllib2.urlopen('http://169.254.169.254/latest/meta-data/instance-id').read()
region = urllib2.urlopen('http://169.254.169.254/latest/meta-data/placement/availability-zone').read()[:-1]

def multiply(multiplier, value):
    if multiplier == 'KB':
        return value * 1024
    if multiplier == 'MB':
        return value * 1024 * 1024
    if multiplier == 'GB':
        return value * 1024 * 1024 * 1024
    if multiplier == 'TB':
        return value * 1024 * 1024 * 1024 * 1024
    if multiplier == 'PB':
        return value * 1024 * 1024 * 1024 * 1024 * 1024

raw_output = subprocess.check_output("/usr/bin/docker info --format '{{json .}}'", shell=True)

docker_info = json.loads(raw_output)

for item in docker_info['DriverStatus']:
    if item[0] == 'Data Space Used':
        raw_used=item[1]
    if item[0] == 'Data Space Total':
        raw_total=item[1]

total = raw_total[:-2]
used = raw_used[:-2]

total_multiplier = raw_total[-2:]
used_multiplier = raw_used[-2:]

total = multiply(total_multiplier, float(total))
used = multiply(used_multiplier, float(used))

data_used_percent = used/total*100

ec2 = boto3.client('ec2', region_name=region)

response = ec2.describe_tags(
    Filters=[
        {
            'Name': 'resource-id',
            'Values': [ instanceid ],
        }
    ]
)

asgname='default'
for tag in response['Tags']:
    if tag['Key'] != 'aws:autoscaling:groupName':
        continue
    asgname = tag['Value']

cw = boto3.client('cloudwatch', region_name=region)

response = cw.put_metric_data(
    Namespace='Docker',
    MetricData=[
        {
            'MetricName': 'data_used_percent',
            'Dimensions': [
                { 'Name': 'AutoScalingGroupName', 'Value': asgname }
            ],
            'Value': data_used_percent,
            'Unit': 'Percent',
        },
    ],
)