#!/usr/bin/env python

#

# updates instance tag in ec2, with puppet classes (and more)

# run from each instance, periodically.

#

# Requires:

# * You dump all facts from puppet to a .yaml file, so we can read applied classes

# See: http://www.semicomplete.com/blog/geekery/puppet-facts-into-mcollective.html

# * Instance metadata service is enabled

#

# Caveat: EC2 only allows 255 chars for the value. You must limit the number of

# classes you shove in the 'puppet_classes' key. See the two vars below the imports.

import boto.ec2

import sys

import collections

import yaml

puppet_class_tag_key = 's_classes'

puppet_class_tag_val_startswith = 's_' # the classes we care about start with s_*

puppet_class_tag_ignore = 'params' # if it has that string, don't care

facts_yaml = '/mnt/tmp/facts.yaml'

def get_current_region():

return boto.utils.get_instance_metadata()['placement']['availability-zone'].strip().lower()[:-1]

if __name__ == '__main__':

tags_dict = {}

with open(facts_yaml) as fh:

puppet = yaml.safe_load(fh)

regions = boto.ec2.regions()

region = [region for region in regions if get_current_region() in region.name][0]

instance_id = boto.utils.get_instance_metadata()['instance-id']

ec2 = region.connect()

res = ec2.get_all_instances(filters={'instance-id': instance_id})[0]

instance = res.instances[0]

#print instance.tags.get('Name'), instance.id, instance.placement

s_classes = ','.join([str(classes) for classes in puppet['krux_classes'].split()

if classes.startswith(puppet_class_tag_val_startswith)

and puppet_class_tag_ignore not in classes])

tags_dict.update({puppet_class_tag_key: s_classes[-254:]})

# also, add the environment tag

tags_dict.update({'environment': puppet.get('environment')[-254:]})

# cluster name!

tags_dict.update({'cluster_name': puppet.get('cluster_name')[-254:]})

# make the API call:

ec2.create_tags([instance.id], tags_dict)