Maps Elastic IP from AWS EC2 tag AutoMapElasticIP to current instance

AutoMapElasticIP.php

<?php

/*
//Required Permissions for IAM
{
  "Statement": [
    {
      "Action": [
        "ec2:AssociateAddress",
        "ec2:DescribeAddresses",
        "ec2:DescribeTags"
      ],
      "Effect": "Allow",
      "Resource": [
        "*"
      ]
    }
  ]
}
*/
error_reporting(-1);
$instanceId=exec('ec2metadata --instance-id');
print_r($instanceId);

require_once 'AWSSDKforPHP/sdk.class.php';

$ec2 = new AmazonEC2();
$ec2->set_region(AmazonEC2::REGION_EU_W1);
//$ec2->hostname = 'ec2.eu-west-1.amazonaws.com';
echo("\nUsing hostname: ".$ec2->hostname);

//$r=$ec2->describe_addresses();
//print_r($r->body->addressesSet);

$tagResponse = $ec2->describe_tags(array(
        'Filter'=>array(
            'Name' => 'key',
            'Value' => 'AutoMapElasticIP',
        ),
    )
);
print_r($tagResponse->body);

$tagItem = $tagResponse->body->tagSet->item;
if(!$tagItem)
{
    echo 'Tag with name "AutoMapElasticIP" does not exists';
    exit(1);
}

$addrResponse=$ec2->describe_addresses(
    array(
        'PublicIp' => $tagItem->value,
    )
);

print_r($addrResponse->body);

$addrItem = $addrResponse->body->addressesSet->item;

if($tagItem->resourceId==$instanceId && $addrItem->instanceId==$instanceId)
{
    echo "\nIP ".$tagItem->value." is already mapped to ".$instanceId.".\n";
    exit(0);
}

$assocResponse=$ec2->associate_address($instanceId,$tagItem->value);
print_r($assocResponse->body);

echo "\n\n";
?>