Created new function to offsite SnapShots based upon presence of 'DestinationRegion' Tag; if the Tag is present, it must be a valid AWS Region which will trigger replication of the SnapShot to the specified Region, and then delete the SnapShot from the Source Region in any subsequent re-run after the copy has completed successfully. All Tags on the Source SnapShot will be applied to the copy.

Author: Dave Osment

ebs-snapshot-offsiter.py

@@ -0,0 +1,114 @@
+import boto3
+import collections
+import datetime
+import os
+
+ec = boto3.client('ec2')
+
+def lambda_handler(event, context):
+
+	# Get Current Region
+	aws_region = os.getenv('AWS_REGION')
+
+	# Get All SnapShots With 'Offsite' Tag Set
+	snapshots = ec.describe_snapshots(
+		Filters=[
+			{ 'Name': 'tag-key', 'Values': ['DestinationRegion'] },
+		]
+	)
+
+	for snapshot in snapshots['Snapshots']:
+
+		# Reset Our Destination Region
+		destination_region = None
+
+		# Obtain Tags From Source SnapShot
+		for tag in snapshot['Tags']:
+			
+			# Obtain Destination Region From Source Snapshot Tag
+			if tag['Key'] == 'DestinationRegion':
+				destination_region = tag['Value']
+
+			# Check If We Need To Do A Copy Or Not
+			if destination_region == aws_region:
+
+				print "\tDestination Region %s is the same as current region (%s) - skipping copy" % (
+					destination_region,
+					aws_region
+				)
+
+				continue
+
+		# Construct ec2 Client For Secondary Region
+		secondary_ec = boto3.client('ec2', region_name=destination_region)
+
+		# Determine If There's An Off-Site Copy Of This SnapShot
+		os_snapshots = secondary_ec.describe_snapshots(
+			Filters=[
+				{ 'Name': 'tag:SourceSnapshotId', 'Values': [snapshot['SnapshotId']] },
+				{ 'Name': 'status', 'Values': ['pending','completed'] },
+			]
+		)
+
+		# We Only Want To Delete Where Snapshot Has Copied Successfully
+		if len(os_snapshots['Snapshots']) >= 1:
+
+			snapshot_states = [d['State'] for d in os_snapshots['Snapshots']]
+
+			if 'pending' in snapshot_states:
+				print "\tThere is at least 1 Snapshot copy pending in %s - skipping delete & copy" % (
+					destination_region
+				)
+				
+				continue					
+
+			print "\t\tFound a corresponding Snapshot with Id %s in %s created from Snapshot %s" % (
+				os_snapshots['Snapshots'][0]['SnapshotId'],
+				destination_region,				
+				snapshot['SnapshotId']
+			)
+
+			print "Deleting source Snapshot %s from %s" % (
+				snapshot['SnapshotId'],
+				aws_region
+			)
+
+			ec.delete_snapshot(
+				DryRun=True,
+				SnapshotId=snapshot['SnapshotId']
+			)
+
+			continue
+
+		# Create Copy Of Snapshot Because One Doesn't Exist
+		os_snapshot = secondary_ec.copy_snapshot(
+			SourceRegion=aws_region,
+			SourceSnapshotId=snapshot['SnapshotId'],
+			Description=snapshot['Description'],
+			DestinationRegion=destination_region
+		)
+
+		# If Snapshot Copy Executed Successfully, Copy The Tags
+		if (os_snapshot):
+
+			print "\t\tSnapshot copy %s created in %s of %s from %s" % (
+				os_snapshot['SnapshotId'],
+				destination_region,
+				snapshot['SnapshotId'],
+				aws_region
+			)
+
+			# Add Tags To Off-Site SnapShot
+			destination_snapshot_tags = snapshot['Tags'] + [{ 'Key': 'SourceSnapshotId', 'Value': snapshot['SnapshotId'] }]
+			secondary_ec.create_tags(
+				Resources=[os_snapshot['SnapshotId']],
+				Tags=destination_snapshot_tags					
+			)
+
+			# Add Tags To Source SnapShot
+			ec.create_tags(
+				Resources=[snapshot['SnapshotId']],
+				Tags=[
+					{ 'Key': 'OffsiteSnapshotId', 'Value': os_snapshot['SnapshotId'] },
+				]
+			)