prune_ebs_snapshots

#!/usr/bin/php -q
<?php
# ------------------------------------------------------------------
# We offer no warantee or guarantee - use this code at your own risk!
# All code is Copyright (C) 2011, Applied Trust Engineering, Inc.
# ------------------------------------------------------------------

putenv('TZ=America/Denver');
$debug = 0;

$options = getopt("S:K:v:a:p:d");
if (!isset($options["S"])) { usage(); }
if (!isset($options["K"])) { usage(); }
if (!isset($options["v"])) { usage(); }
if (!isset($options["a"])) { usage(); }
if (!isset($options["p"])) { usage(); }
if (isset($options["d"])) { $debug = 1; }

define('AWS_KEY', $options["K"]);
define('AWS_SECRET_KEY', $options["S"]);

error_reporting(-1);
require_once '/usr/local/aws-php-sdk/sdk.class.php';

$regions = array (
	'E1' => 'http://monitoring.amazonaws.com/doc/2010-08-01/CloudWatch.wsdl',
	'W1' => 'http://monitoring.us-west-1.amazonaws.com/doc/2010-08-01/CloudWatch.wsdl',
	'EU' => 'http://monitoring.eu-west-1.amazonaws.com/doc/2010-08-01/CloudWatch.wsdl',
	'AP' => 'http://monitoring.ap-southeast-1.amazonaws.com/doc/2010-08-01/CloudWatch.wsdl',
	);

$quarters = array (
	'01' => '1',
	'02' => '1',
	'03' => '1',
	'04' => '2',
	'05' => '2',
	'06' => '2',
	'07' => '3',
	'08' => '3',
	'09' => '3',
	'10' => '4',
	'11' => '4',
	'12' => '4',
	);

# Allow for a comma-separated list of volumes
$volumes = preg_split('/,/', $options["v"]);

$archive = $options["a"];
$period = $options["p"];

if (($period != "q") && ($period != "m")) {
	echo "Period option must be either q (quarterly) or m (monthly).";
	usage();
}

$ec2 = new AmazonEC2();

// Get the response from a call to the DescribeImages operation.
$response = $ec2->describe_snapshots();

$errors = 0;
$successes=0;
$now = time();
$oneday = 86400;
$olderthan = $now-($archive*$oneday);

log_message("finished fetching list of snapshots, beginning to parse.");
log_message("archive duration is $archive days, or older than " . date("m-d-Y H:i", $olderthan));
if ($period == "q") {
	log_message("period retention is quarterly");
}
else {
	log_message("period retention is monthly");
}

$all_snapshots = array();
foreach ( $response->body->snapshotSet->item as $snapshot) {
	$temparray = array(
		'snapshotId' => $snapshot->snapshotId,
		'volumeId'   => $snapshot->volumeId,
		'startTime'  => $snapshot->startTime,
	);
	array_push($all_snapshots, $temparray);
}

#foreach ($all_snapshots as $mysnap) {
#	echo "snapshotId: " . $mysnap['snapshotId'] . "\n";
#	echo "volumeId: " . $mysnap['volumeId'] . "\n";
#	echo "startTime: " . $mysnap['startTime'] . "\n\n";
#}
#exit;


foreach ($volumes as $volid) {
	log_message("Examining volume $volid...");

	$snaplist=array();
	foreach ($all_snapshots as $snapshot) {
		if ($snapshot['volumeId'] == $volid) {
			$snaplist[strtotime($snapshot['startTime'])] = $snapshot['snapshotId'];
		}
	}

	ksort ($snaplist);
	$keepers = array();
	foreach ($snaplist as $ts => $id) {
		log_message("examining $id - " . date("m-d-Y H:i", $ts));

		# this is crazy black magic to deal with retaining one snapshot per period
		$month = date("m", $ts);
		$quarter = $quarters[$month];;
		log_message("\ttaken in quarter: $quarter");
		log_message("\ttaken in month: $month");

		# first check if this is the first snapshot in the rentention period (quarter or month)
		if (($period == "q") && (!isset($keepers[$quarter]))) {
			log_message("\tkeeping because it's the first in quarter $quarter");
			$keepers[$quarter] = $id;
			continue;
		}
		if (($period == "m") && (!isset($keepers[$month]))) {
			log_message("\tkeeping because it's the first in month $month");
			$keepers[$month] = $id;
			continue;
		}
	
		# finally, keep if > $archive days old
		if ($ts > $olderthan) {
			log_message("\tkeeping because it's more recent than the archive duration");
			continue;
		} 
	
		# if we've gotten this far, we can delete the snapshot
		if ($debug) {
			log_message("\tIF THIS WERE NOT DEBUG MODE THIS SNAPSHOT WOULD BE DELETED!");
			continue;
		}
		$response = $ec2->delete_snapshot($id);
		if ($response->isOK()) {
			$successes++;
		} 
		else if (strcmp($response->body->Errors->Error->Code, 'InvalidSnapshot.InUse')==0) {
			log_message("\tskipped because it's in use (perhaps for an AMI)");
			continue;
		} 
		else {
			$errors++;
		}
	}
}

if ($errors) {
	echo "prune_ebs_snapshots CRITICAL - Error pruning snapshots\n";
	exit(2);
} 
else {
	echo "prune_ebs_snapshots OK - $successes snapshots pruned\n";
	exit(0);
}


############################################################

function log_message($message) {
	global $debug;
	if ($debug) {
		echo "$message\n";
	}
}

function usage() {
	echo "usage: prune_ebs_snapshot -K <access_key_id> -S <secret_access_key> -v <volume_id(s)> -a <archive duration> -p <period>\n";
	exit(1);
}