Mock a Cloud-Init metadata service for cloud-config testing with VirtualBox Guest VM

Cloud-Init_MetadataRouter.php

<?php

date_default_timezone_set(
	'UTC'
);

// Mock Cloud-Init metadata service for cloud-config

// From VirtualBox host machine run: 
//  env METADATA_INSTANCE_ID="iid-5cd832f4bc69" sudo -E php -S 0.0.0.0:80 Cloud-Init_MetadataRouter.php

// http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-metadata.html
// http://docs.cloudstack.apache.org/projects/cloudstack-administration/en/latest/virtual_machines.html#user-data-and-meta-data

function getUuid() {
	return sprintf(
		'%04x%04x-%04x-%04x-%04x-%04x%04x%04x',
		mt_rand(0, 0xffff), 
		mt_rand(0, 0xffff),
		mt_rand(0, 0xffff),
		mt_rand(0, 0x0fff) | 0x4000,
		mt_rand(0, 0x3fff) | 0x8000,
		mt_rand(0, 0xffff), 
		mt_rand(0, 0xffff), 
		mt_rand(0, 0xffff)
	);
}

function getInstanceId($uuid = '') {

	if (
		! is_string($uuid)
	) {
		$uuid = '';
	}

	return sprintf(
		'iid-%s',
		substr(
			sha1 (
				! empty($uuid)
				? $uuid
				: getUuid()
			),
			0,
			12
		)
	);
}

$metadataVersions = array(
	'latest'
);

$metadataVersionPatterns = array(
	'/^\/\/?latest/'
);

$requestUri = isset($_SERVER["REQUEST_URI"]) 
	? $_SERVER["REQUEST_URI"]
	: "/"
;

// Normalise URI
// - Replace double leading // with single /
// - Replace version URI slug with placeholder
$requestUriPattern = preg_replace(
	$metadataVersionPatterns,
	'/{{METADATA_VERSION}}', 
	$requestUri
);

$userDataFile = realpath(
	__DIR__ . '/user-data'
);


$timeStamp = strftime(
	'[%d/%b/%Y:%T %z]'
);

$headers = array(
	$timeStamp
);

if ( ! empty($_SERVER)) {
	foreach ($_SERVER as $key => $value) {

		// Limit headers
		if ( ! preg_match(
			'/^(HTTP_|REMOTE_ADDR|SERVER_NAME|SERVER_PORT|REQUEST_URI|REQUEST_METHOD)/', 
			$key
		)) {
			continue;
		}

		$headers[] = sprintf(
			'%s: %s',
			preg_replace(
				'/_/',
				'-',
				mb_convert_case(
					$key, 
					MB_CASE_TITLE, 
					'UTF-8'
				) 
			),
			$value
		);

	}
}

// Basic request logging
file_put_contents(
	"var/log/metadata_log",
	! empty($headers) 
		? implode(PHP_EOL, $headers) . PHP_EOL 
		: ''
);

switch ($requestUriPattern) {
	case '/':
		header(
			'Content-Type: text/plain; charset=UTF-8',
			true,
			200
		);

		print implode(
			PHP_EOL,
			$metadataVersions
		) . PHP_EOL;

		break;
	case '/{{METADATA_VERSION}}':
	case '/{{METADATA_VERSION}}/':
		header(
			'Content-Type: text/plain; charset=UTF-8',
			true,
			200
		);

		print implode(
			PHP_EOL,
			array(
				'meta-data',
				'user-data'
			)
		) . PHP_EOL;

		break;
	case '/{{METADATA_VERSION}}/meta-data':
	case '/{{METADATA_VERSION}}/meta-data/':
		header(
			'Content-Type: text/plain; charset=UTF-8',
			true,
			200
		);

		print implode(
			PHP_EOL,
			array(
				'hostname',
				'instance-id'
			)
		) . PHP_EOL;

		break;
	case '/{{METADATA_VERSION}}/meta-data/hostname':
		header(
			'Content-Type: text/plain; charset=UTF-8',
			true,
			200
		);
	
		print ( ! empty(getenv('METADATA_HOSTNAME')) 
			? getenv('METADATA_HOSTNAME')
			: substr(
					sha1 (
						! empty($uuid)
						? $uuid
						: getUuid()
					),
					0,
					12
				)
		) . PHP_EOL;
	
		break;
	case '/{{METADATA_VERSION}}/meta-data/local-hostname':
		header(
			'Content-Type: text/plain; charset=UTF-8',
			true,
			200
		);
	
		print ( ! empty(getenv('METADATA_LOCAL_HOSTNAME')) 
			? getenv('METADATA_LOCAL_HOSTNAME')
			: substr(
					sha1 (
						! empty($uuid)
						? $uuid
						: getUuid()
					),
					0,
					12
				)
		) . PHP_EOL;
	
		break;
	case '/{{METADATA_VERSION}}/meta-data/instance-id':
		header(
			'Content-Type: text/plain; charset=UTF-8',
			true,
			200
		);

		print ( ! empty(getenv('METADATA_INSTANCE_ID')) 
			? getenv('METADATA_INSTANCE_ID')
			: getInstanceId() 
		) . PHP_EOL;

		break;
	case '/{{METADATA_VERSION}}/user-data':
		if ($userDataFile !== false) {
			header(
				'Content-Type: text/plain; charset=UTF-8',
				true,
				200
			);

			readfile(
				$userDataFile
			);
			
		} else {
			header(
				'Content-Type: text/plain; charset=UTF-8',
				true,
				404
			);

			print '404 - Not Found' . PHP_EOL;
		}

		break;
	default:
		header(
			'Content-Type: text/plain; charset=UTF-8',
			true,
			404
		);

		print '404 - Not Found' . PHP_EOL;
}