ebs_set_names.py

ebs_set_names.py

#!/usr/bin/env python
#
# Set names on unnamed EBS volumes from their attached EC2 instance.
#
# Requires:
#  - aws: https://github.com/aws/aws-cli (tested with aws-1.0.0)
#  - jq: http://stedolan.github.io/jq/ (tested with jq-1.3)


import os, sys, json, subprocess


def show_cmd(cmd):
    print '$', cmd
    return cmd


def shell(cmd):
    return subprocess.check_output(cmd, shell=True)


# This isn't set when we're run by cron [FIXME]
os.environ['AWS_CONFIG_FILE'] = '~/.awscli'


# (`aws` is actually easier to figure out than boto directly...)
instances = json.loads(shell('''
    aws ec2 describe-instances | jq '
        [ .Reservations[].Instances[] | {
            key:   .InstanceId,
            value: {
                Tags: (.Tags // {} | map(with_entries(
                    if .key == "Key" then .key = "key" elif .key == "Value" then .key = "value" else . end
                )) | from_entries // {})
            }
        } ] | from_entries
    '
'''))


volumes = json.loads(shell('''
    aws ec2 describe-volumes | jq '
        [ .Volumes[] | {
            key:   .VolumeId,
            value: {
                InstanceId: (
                    .VolumeId as $id | .Attachments | map(select(.VolumeId == $id and .State == "attached")) | .[0].InstanceId
                ),
                Tags: (.Tags // {} | map(with_entries(
                    if .key == "Key" then .key = "key" elif .key == "Value" then .key = "value" else . end
                )) | from_entries // {})
            }
        } ] | from_entries
    '
'''))


for v_id, v in sorted(volumes.items()):
    if v['Tags'].get('Name'):
        print '%s: Skipping, already named: %s' % (v_id, json.dumps(v['Tags']['Name']))
    elif not v.get('InstanceId'):
        print '%s: No attached instance' % v_id
    elif not instances.get(v['InstanceId']):
        print '%s: Attached instance %s not found' % (v_id, v['InstanceId'])
    elif not instances[v['InstanceId']]['Tags'].get('Name'):
        print '%s: Attached instance %s has no name' % (v_id, v['InstanceId'])
    else:
        name = instances[v['InstanceId']]['Tags']['Name']
        print '%s: Setting name %s (from %s)' % (v_id, json.dumps(name), v['InstanceId'])
        shell(show_cmd("aws ec2 create-tags --resources %s --tags Key=Name,Value='%s'" % (
            v_id,
            name.replace(',', '\,').replace('=', '\='),
        )))