Give a summary of currently running/pending AWS instances, and how many are being used out of the limit.

aws_instances.py

# Setup:
# 1) sudo pip install awscli
# 2) the following environment variables must be set
#   - $ export AWS_ACCESS_KEY_ID=<access_key>
#   - $ export AWS_SECRET_ACCESS_KEY=<secret_key>

import collections
import datetime
import json
import subprocess

print datetime.datetime.now()

region_names = ['us-west-2', 'us-west-1', 'us-east-1']

key_names = []
for region_name in region_names:
    for reservation in json.loads(subprocess.check_output(['aws', '--region', region_name, 'ec2', 'describe-instances', '--filter', 'name=instance-state-code,values=0,16']))['Reservations']:
            for instance in reservation['Instances']:
                key_names.append(', '.join(group['GroupName'] for group in instance['SecurityGroups']))

    instance_counts = collections.Counter(key_names)
    running_instances = sum(instance_counts.values())
    max_instances = json.loads(subprocess.check_output(['aws', '--region', region_name, 'ec2', 'describe-account-attributes', '--attribute-names', 'max-instances']))['AccountAttributes'][0]['AttributeValues'][0]['AttributeValue']
    print "\n{}, using: {}/{}".format(region_name, running_instances, max_instances)
    for k, v in instance_counts.iteritems():
        print "\t{} : {}".format(k, v)