Using awscli to manage ec2 snapshots (creation, cleanup) with php.

ec-manage-snapshots.php

<?php

// Using awscli for this. Would probably be better in python but this was quick and simple.

date_default_timezone_set ('UTC');

/**
 * Executes aws command and returns output as PHP array.
 */
function _exec_aws_command($command) {
  exec($command, $value);
  return json_decode(implode($value, "\n"));
}

function create_snapshots($options) {
  $volumes = _exec_aws_command('aws ec2 describe-volumes');
  foreach ($volumes->Volumes as $volume) {
    if ($volume->State == 'in-use') {
      _exec_aws_command('aws ec2 create-snapshot --volume-id ' . $volume->VolumeId . ' --description "' . $options['filter'] . ' snapshot - ' . date('c') . '"');
    }
  }
}

function cleanup_snapshots($options) {
  $volumes = _exec_aws_command('aws ec2 describe-volumes');
  foreach ($volumes->Volumes as $volume) {
    $snapshots = _exec_aws_command('aws ec2 describe-snapshots --filter Name=volume-id,Values=' . $volume->VolumeId);
    $snaps = array();
    foreach ($snapshots->Snapshots as $snapshot) {
      if (strpos($snapshot->Description, $options['filter']) !== FALSE) {
        $timestamp = strtotime($snapshot->StartTime);
        $snaps[$snapshot->SnapshotId] = $timestamp;
      }
    }
    arsort($snaps);
    $current = 0;
    foreach ($snaps as $snapshot_id => $values) {
      $current++;
      if ($current > $options['limit']) {
        _exec_aws_command('aws ec2 delete-snapshot --snapshot-id ' . $snapshot_id);
        print "Delete snapshot id {$snapshot_id}.";
      }
    }
  }
}

function main() {
  $defaults = array(
    'action' => 'create',
    'filter' => 'daily',
    'limit' => '4',
  );
  $options = getopt('', array('action::', 'filter::', 'limit::'));
  $options = array_merge($defaults, $options);

  if ($options['action'] == 'create') {
    create_snapshots($options);
  }
  else if ($options['action'] == 'cleanup') {
    cleanup_snapshots($options);
  }
  else {
    print ("No such action exists.");
  }
}

main();