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Given a tag, search for the most recent snapshot, create a volume and mount it.
#! /usr/bin/python
from boto import ec2
import boto.utils
import argparse, time, os, json
def parsed_args():
parser = argparse.ArgumentParser()
parser.add_argument("-g", "--instance_tags",
help='the tags you want to apply to your instance. default: {"Name","app", "Environment":"Production", "Role":"app"}',
default='{"Name","app", "Environment":"Production", "Role":"app"}')
parser.add_argument("-i", "--instance_id",
help="the instance id you want to snapshot. default: current instance id",
default=boto.utils.get_instance_metadata()['instance-id'])
parser.add_argument('-m', "--device_key",
help="the desired mount point as defined by aws. default: /dev/sdf",
default='/dev/sdf')
parser.add_argument('-v', "--device_value",
help="the desired mount point as defined by your os. For example ubuntu turns /dev/sdf to /dev/xvdf. default: /dev/xvdf",
default='/dev/xvdf')
parser.add_argument('-r', "--region",
help="the region you're in. default: us-west-2",
default='us-west-2')
parser.add_argument('-t', "--snapshot_tag",
help="the snapshot tag you're looking for. default: codepen-app",
default='codepen-app')
parser.add_argument('-s', "--volume_size",
help="the volume size in GiB. default: 5",
default='5')
parser.add_argument('-z', "--availability_zone",
help="The availability_zone in which to create the volume. Will be appended to the region arg. default: c",
default='c')
return parser.parse_args()
def main():
args = parsed_args()
conn = ec2.connect_to_region(args.region)
snapshot = most_recent_snapshot(conn, args)
volume = create_volume_from_snapshot(conn, args, snapshot)
attach_snapshot_to_volume(conn, args, volume)
apply_launch_tags(conn, args)
print 'done!'
exit(0)
def most_recent_snapshot(conn, args):
snapshots = conn.get_all_snapshots(
owner='self',
filters={'tag:Name':args.snapshot_tag})
snapshots.sort(date_compare)
if (len(snapshots) > 1):
return snapshots[0]
else:
raise Exception('No snapshot found for tag %s' % args.snapshot_tag)
def create_volume_from_snapshot(conn, args, snapshot):
volume = conn.create_volume(
args.volume_size,
args.region + args.availability_zone,
snapshot)
wait_volume(conn, args, volume, 'available')
volume.add_tag('Name', '%s. instance id: %s' % (args.snapshot_tag, args.instance_id))
return volume
def attach_snapshot_to_volume(conn, args, volume):
volume_status = conn.attach_volume(volume.id, args.instance_id, args.device_key)
wait_volume(conn, args, volume, 'in-use')
wait_fstab(args, 'present')
return True
def wait_fstab(args, expected_status):
volume_status = 'not present'
sleep_seconds = 2
sleep_intervals = 30
for counter in range(sleep_intervals):
print 'elapsed: %s. status: %s.' % (sleep_seconds * counter, volume_status)
try:
os.stat(args.device_value)
volume_status = expected_status
except: OSError
# mount does not exsit yet
# try again later
if volume_status == expected_status:
break
time.sleep(sleep_seconds)
if volume_status != expected_status:
raise Exception('Unable to get %s status for volume %s' % (expected_status, volume.id))
print 'volume now in %s state' % expected_status
def wait_volume(conn, args, volume, expected_status):
volume_status = 'waiting'
sleep_seconds = 2
sleep_intervals = 30
for counter in range(sleep_intervals):
print 'elapsed: %s. status: %s.' % (sleep_seconds * counter, volume_status)
conn = ec2.connect_to_region(args.region)
volume_status = conn.get_all_volumes(volume_ids=[volume.id])[0].status
if volume_status == expected_status:
break
time.sleep(sleep_seconds)
if volume_status != expected_status:
raise Exception('Unable to get %s status for volume %s' % (expected_status, volume.id))
print 'volume now in %s state' % expected_status
def date_compare(snap1, snap2):
if snap1.start_time < snap2.start_time:
return 1
elif snap1.start_time == snap2.start_time:
return 0
return -1
def apply_launch_tags(conn, args):
tags = json.loads(args.instance_tags)
conn.create_tags([args.instance_id], tags)
def snapshot_description(volume, instance_id):
return "deployment snapshot of volume %s on instance %s" % (volume.id, instance_id)
if __name__ == '__main__':
main()
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