AWS Instance Age Report (run `make profile=default` if you have many creds profiles defined use the correct one

ages.rb

#!/usr/bin/env ruby

require 'date'
require 'json'

start = DateTime.now().strftime("%s").to_i
divisor = 60 * 60 * 24

r = JSON.parse(ARGF.read)['Reservations']
    .collect { |r| r['Instances'] }
    .flatten
    .select { |i| i['State']['Name'] == 'running' }
    .map { |i| i['LaunchTime'] }
    .map { |i| DateTime.parse(i).strftime('%s').to_i }
    .map { |i| (start - i) / divisor }
    .sort
    .reverse
    .each { |i| puts i }

chart.py

#!/usr/local/opt/python/bin/python2.7
# -*- coding: utf-8 -*-
#
# Copyright 2010 Bitly
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.

"""
Generate an ascii bar chart for input data

https://github.com/bitly/data_hacks
"""
import sys
import math
from collections import defaultdict
from optparse import OptionParser
from decimal import Decimal

def load_stream(input_stream):
    for line in input_stream:
        clean_line = line.strip()
        if not clean_line:
            # skip empty lines (ie: newlines)
            continue
        if clean_line[0] in ['"', "'"]:
            clean_line = clean_line.strip('"').strip("'")
        if clean_line:
            yield clean_line

def run(input_stream, options):
    data = defaultdict(int)
    total = 0
    for row in input_stream:
        if options.agg_key_value:
            kv = row.rstrip().rsplit(None, 1)
            value = int(kv[1])
            data[kv[0]] += value
            total += value
        elif options.agg_value_key:
            kv = row.lstrip().split(None, 1)
            value = int(kv[0])
            data[kv[1]] += value
            total += value
        else:
            data[row] += 1
            total += 1

    if not data:
        print "Error: no data"
        sys.exit(1)

    max_length = max([len(key) for key in data.keys()])
    max_length = min(max_length, 50)
    value_characters = 80 - max_length
    max_value = max(data.values())
    scale = int(math.ceil(float(max_value) / value_characters))
    scale = max(1, scale)

    print "# each ∎ represents a count of %d. total %d" % (scale, total)

    if options.sort_values:
        data = [[value, key] for key, value in data.items()]
        data.sort(key=lambda x: x[0], reverse=options.reverse_sort)
    else:
        # sort by keys
        data = [[value, key] for key, value in data.items()]
        if options.numeric_sort:
            # keys could be numeric too
            data.sort(key=lambda x: (Decimal(x[1])), reverse=options.reverse_sort)
        else:
            data.sort(key=lambda x: x[1], reverse=options.reverse_sort)

    str_format = "%" + str(max_length) + "s [%6d] %s%s"
    percentage = ""
    for value, key in data:
        if options.percentage:
            percentage = " (%0.2f%%)" % (100 * Decimal(value) / Decimal(total))
        print str_format % (key[:max_length], value, (value / scale) * "∎", percentage)

if __name__ == "__main__":
    parser = OptionParser()
    parser.usage = "cat data | %prog [options]"
    parser.add_option("-a", "--agg", dest="agg_value_key", default=False, action="store_true",
                        help="Two column input format, space seperated with value<space>key")
    parser.add_option("-A", "--agg-key-value", dest="agg_key_value", default=False, action="store_true",
                        help="Two column input format, space seperated with key<space>value")
    parser.add_option("-k", "--sort-keys", dest="sort_keys", default=True, action="store_true",
                        help="sort by the key [default]")
    parser.add_option("-v", "--sort-values", dest="sort_values", default=False, action="store_true",
                        help="sort by the frequence")
    parser.add_option("-r", "--reverse-sort", dest="reverse_sort", default=False, action="store_true",
                        help="reverse the sort")
    parser.add_option("-n", "--numeric-sort", dest="numeric_sort", default=False, action="store_true",
                        help="sort keys by numeric sequencing")
    parser.add_option("-p", "--percentage", dest="percentage", default=False, action="store_true",
                        help="List percentage for each bar")

    (options, args) = parser.parse_args()

    if sys.stdin.isatty():
        parser.print_usage()
        print "for more help use --help"
        sys.exit(1)
    run(load_stream(sys.stdin), options)

Makefile

fresh: clean chart

chart: instance_ages
	@echo "AWS EC2 Instance Age Report"
	@echo "---------------------------"
	@echo "Days\\tCount"
	@cat instance_ages | ./chart.py -n

clean:
	rm -f instance*

instance_ages: instances.json
	./ages.rb instances.json > instance_ages

instances.json:
	aws --profile ${profile} ec2 describe-instances --output=json > instances.json