Serverless

Menjalankan kode aplikasi tanpa perlu memikirkan server (autoscaling dkk).

Dalam konteks ini adalah Function as a Service (FaaS).

Keuntungan Serverless

{Zero Administration} {Bayar per Eksekusi} {Idle = Gratis} {Auto-Scaling} {Microservice sejak awal} {Event-Driven} {Faster time to market}

VM vs Serverless

Yang akan kamu kerjakan

Cara Kerja Lambda

Lambda Runtime

Gabungan dari sistem operasi, bahasa pemrograman dan pustaka-pustaka lain yang dibutuhkan untuk menjalankan kode.

Contoh Kode Python

def my_handler(event, context):
  return {
    "message": "Hello World"
  }

Contoh Event dari API Gateway

{
    "resource": "/",
    "path": "/",
    "httpMethod": "GET",
    "requestContext": {
        "resourcePath": "/",
        "httpMethod": "GET",
        "path": "/Prod/",
        ...
    },
    "headers": {
        "accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9",
        "accept-encoding": "gzip, deflate, br",
        "Host": "70ixmpl4fl.execute-api.us-east-2.amazonaws.com",
        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.132 Safari/537.36",
        "X-Amzn-Trace-Id": "Root=1-5e66d96f-7491f09xmpl79d18acf3d050",
        ...
    },
    "multiValueHeaders": {
        "accept": [
            "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9"
        ],
        "accept-encoding": [
            "gzip, deflate, br"
        ],
        ...
    },
    "queryStringParameters": null,
    "multiValueQueryStringParameters": null,
    "pathParameters": null,
    "stageVariables": null,
    "body": null,
    "isBase64Encoded": false
}

Perkenalkan Bref PHP

Bref adalah Runtime PHP, Framework dan deployment tool agar PHP dapat dijalankan di AWS Lambda.

Bref PHP Runtime

Dibuat dari amazonlinux:2018.03 Docker image

Konsep Eksekusi Custom Runtime

Serverless Demo App

*) Hanya menggunakan Bref PHP Runtime tanpa Bref Framework

Install Bref dan Pustaka Terbilang

$ cat composer.json

{
  "require": {
	"bref/bref": "^0.5.29",
	"rioastamal/terbilang": "^1.0"
  }
}

$ composer install -vvv

Inisialisasi Bref PHP

$ ./vendor/bin/bref init

What kind of lambda do you want to create? (you will be able to add more functions later by editing `serverless.yml`) [PHP function]:
 [0] PHP function
 [1] HTTP application
 [2] Console application
> 0

File Handler index.php

<?php declare(strict_types=1);

require __DIR__ . '/vendor/autoload.php';

use RioAstamal\AngkaTerbilang\Terbilang;

/**
 * @param array $event
 * @see https://docs.aws.amazon.com/lambda/latest/dg/services-apigateway.html for example
 * @return callable
 */
return function ($event)
{
	$angka = $event['queryStringParameters']['angka'] ?? '0';
	$options = isset($event['queryStringParameters']['pretty']) ? JSON_PRETTY_PRINT : 0 ;

	$response = [
		'angka' => $angka,
		'terbilang' => Terbilang::create()->t($angka)
	];

	return json_encode($response, $options);
};

Deploy Fungsi ke AWS Lambda

$ serverless deploy

Memanggil Terbilang API

$ curl --get -d 'angka=1500,004,300' -d 'pretty' [END_POINT]

{
	"angka": "1500,004,300",
	"terbilang": "satu milyar lima ratus juta empat ribu tiga ratus"
}

Provision Amazon RDS MySQL

$ cd terraform/
$ export AWS_PROFILE=YOUR_PROFILE AWS_DEFAULT_REGION=YOUR_REGION
$ terraform apply

Outputs:

database = {
  "connect" = "mysql -u awsug -h [HOST_NAME] -p serverlessphp"
  "endpoint" = "[HOST_NAME]:3306"
  "engine" = "mysql 5.7.26"
}

Install Bref

$ cat composer.json

{
  "require": {
	"bref/bref": "^0.5.29",
  }
}

$ composer install -vvv

Inisialisasi Bref PHP

$ ./vendor/bin/bref init

What kind of lambda do you want to create? (you will be able to add more functions later by editing `serverless.yml`) [PHP function]:
 [0] PHP function
 [1] HTTP application
 [2] Console application
> 1

File Handler index.php

<?php

$dsn = $_POST['dsn'] ?? '';
$username = $_POST['username'] ?? 'root';
$password = $_POST['password'] ?? '';
$query = $_POST['query'] ?? '';
$pdo = null;

function exec_query($pdo, $query)
{
	if (empty($query)) {
		return '// Result will be shown here';
	}

	$counter = 0;

	try {
		echo '<table>';
		foreach ($pdo->query($query, PDO::FETCH_ASSOC) as $row) {
			// --- HEADING --- //
			if ($counter === 0) {
				echo '<thead><tr>';

				foreach ($row as $key => $val) {
					printf('<td>%s</td>', $key);
				}

				echo '</tr></thead><tbody>';
			}
			// --- /HEADING --- //

			echo '<tr>';
			foreach ($row as $val) {
				printf('<td>%s</td>', $val);
			}
			echo '</tr>';

			$counter++;
		}

		echo '</tbody></table>';
	} catch (PDOException $e) {
		printf('<pre>Error: %s</pre>', $e->getMessage());
	}
}

if ($dsn) {
	try {
		$pdo = new PDO($dsn, $username, $password);
		$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
	} catch (PDOException $e) {
		echo 'Connection failed: ' . $e->getMessage();
	}
}

?><!DOCTYPE html>
<html lang="en">
<head>
	<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
	<title>Query Browser on AWS Lambda</title>
	<style type="text/css">
		label {
			display: block;
		}
		div.label-wrapper {
			width: 300px;
		}
		table {
			border-collapse: collapse;
			width: 100%;
		}
		thead td {
			background-color: #f1f1f1;
			font-weight: bold;
		}
		tr td {
			border: 1px solid #ccc;
			padding: 4px 8px;
		}
	</style>
</head>
<body>
	<h2>Query Browser on AWS Lambda</h2>
	<form method="post">
		<label>MySQL DSN</label>
		<input type="text" name="dsn" placeholder="mysql:dbname=testdb;host=127.0.0.1" style="width: 300px;" value="<?= $dsn ?>">
		<label>Username / Password</label>
		<input type="text" name="username" placeholder="MySQL Username" value="<?= $username; ?>">
		<input type="password" name="password" placeholder="MySQL Password" value="<?= $password; ?>">

		<br><br>
		<label>SQL Query</label>
		<textarea style="width: 99%;height: 200px; font-size: 24px; color: blue;" name="query"><?= htmlentities($query) ?></textarea>
		<input type="submit" value="RUN">
	</form>

	<hr>
	<?php exec_query($pdo, $query) ?>
</body>
</html>

Deploy Web ke AWS Lambda

$ serverless deploy

Memaket Lambda

$ bash build.sh

> Creating zip file into build/function.zip ...
Generating autoload files
Generated autoload files
< Lambda function has been zipped.

Deploy Infra dan Lambda

$ bash deploy.sh

...
Outputs:

demo = {
  "mailhog" = {
    "ec2_ip" = "18.139.0.199"
    "mailhog_auth" = "user = teknocerdas | password = orang.cerdas"
    "ssh_access" = "ssh -i ~/.ssh/teknocerdas.key -o LogLevel=quiet -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null [email protected]"
    "url" = "https://mailhog.teknocerdas.com"
  }
  "s3_bucket" = {
    "butcket_name" = "awsug06-sub-demo"
    "create_example" = "aws s3 cp ./YOUR_FILE.ext s3://awsug06-sub-demo/"
  }
}

#!/bin/sh
# Main entry point for Lambda execution

# Fail on error
set -e

# Outer main loop for execution.
# So if there's next event it will get execute it immediately
while true
do
  # All errors to STDOUT so it can be captured to CloudWatch
  /opt/bin/php "$_HANDLER" 2>&1
done

File src/LambdaRuntime.php

<script type="text/template"><?php
namespace App;

use App\Handler;

class LambdaRuntime
{
  /**
   * Create object from static calls
   *
   * @return App\LambdaRuntime
   */
  public static function create()
  {
    return new static();
  }

  /**
   * Simple abstraction for HTTP GET Lambda invocation
   *
   * @param String $url
   * @return Array
   */
  public function fetch($url)
  {
    $headers = [
      'Content-Type: application/json',
      'User-Agent: BelajarAWS/1.0',
      'Accept: application/json'
    ];
    $options = [
      'http' => [
        'method' => 'GET',
        'header' => implode("\r\n", $headers)
      ]
    ];
    $context = stream_context_create($options);
    $response = file_get_contents($url, false, $context);

    // Parse special variables called $http_response_header
    $requestId = null;

    foreach ($http_response_header as $value) {
      if (preg_match('/Lambda-Runtime-Aws-Request-Id/', $value)) {
        $requestId = trim(explode('Lambda-Runtime-Aws-Request-Id:', $value)[1]);
      }
    }

    return [
      'body' => json_decode($response, $toArray = true),
      'request_id' => $requestId
    ];
  }

  /**
   * Simple abstraction for HTTP POST
   *
   * @param String $url
   * @param String $data
   * @return String
   */
  public function post($url, $data)
  {
    $headers = [
      'Content-Type: application/json',
      'User-Agent: BelajarAWS/1.0',
      'Content-Length: ' . strlen($data)
    ];
    $options = [
      'http' => [
        'method' => 'POST',
        'header' => implode("\r\n", $headers),
        'content' => $data
      ]
    ];

    $context = stream_context_create($options);
    return file_get_contents($url, false, $context);
  }

  /**
   * Lambda main loop
   */
  public function main()
  {
    // AWS_LAMBDA_RUNTIME_API are automatically set by Lambda
    $lambdaRuntimeApi = getenv('AWS_LAMBDA_RUNTIME_API');
    $lambdaBaseUrl = sprintf('http://%s/2018-06-01/runtime/invocation/', $lambdaRuntimeApi);
    $maxLoop = getenv('MAX_LOOP') ?: 10;
    $currentLoop = 0;
    $handler = Handler::create();

    // Inner main loop for execution.
    // So if there's next event it will get execute it immediately
    while (true)
    {
      if (++$currentLoop > $maxLoop) {
        break;
      }

      $nextEvent = $this->fetch($lambdaBaseUrl . 'next');
      $handlerResponse = $handler->handle($nextEvent['body']);

      $responseUrl = sprintf('%s%s/response', $lambdaBaseUrl, $nextEvent['request_id']);
      $lambdaResponse = $this->post($responseUrl, $handlerResponse);
    }
  }
}</script>

File src/Handler.php

<script type="text/php"><?php
/**
 * Lambda function to handle notification from S3 event and then
 * send the info via email (SMTP).
 */
namespace App;
use Tx\Mailer;

class Handler
{
  /**
   * @var array $config - Configuration for the Handler such as
   *      region, endpoint, etc.
   */
  public $config = [];

  /**
   * Constructor
   *
   * @param array $config
   * @return void
   */
  public function __construct(array $config = [])
  {
    $default = [
      'region'      => 'ap-southeast-1',
      'version'     => 'latest',
      'email_addr'  => getenv('AWSUG_EMAIL') ? getenv('AWSUG_EMAIL') : '[email protected]',
      'smtp'        => [
        'host' => getenv('AWSUG_SMTP_HOST') ? getenv('AWSUG_SMTP_HOST') : '[email protected]',
        'port' => getenv('AWSUG_SMTP_PORT') ? getenv('AWSUG_SMTP_PORT') : 587,
        'username' => getenv('AWSUG_SMTP_USER') ? getenv('AWSUG_SMTP_USER') : null,
        'password' => getenv('AWSUG_SMTP_PASSWD') ? getenv('AWSUG_SMTP_PASSWD') : null,
      ]
    ];

    $this->config = array_replace_recursive($default, $config);
  }

  /**
   * Create object from static calls
   *
   * @param array $config
   * @return App\Handler
   */
  public static function create(array $config = [])
  {
    return new static($config);
  }

  /**
   * Handler function which return a response and will be send back to Lambda
   *
   * @param array $event Lambda Event
   * @return String
   */
  public function handle($event)
  {
    $eventTime = $event['Records'][0]['eventTime'];
    $body = sprintf('<h3>Here is the the event info.</h3><pre>%s</pre>', json_encode($event, JSON_PRETTY_PRINT));

    // Send email notification for new file
    $mailer = (new Mailer())
        ->setServer($this->config['smtp']['host'], $this->config['smtp']['port'])
        ->setFrom('Rio Astamal', '[email protected]')
        ->addTo('AWS UG Surabaya', $this->config['email_addr'])
        ->setSubject( sprintf('New file has been uploaded at %s', $eventTime) )
        ->setBody($body)
        ->send();

    $response = [
        'email_status' => (bool)$mailer,
        'requestId' => $event['Records'][0]['responseElements']['x-amz-request-id']
    ];
    return json_encode($response);
  }
}
</script>

Test Email Notification

$ aws s3 cp /some/file.ext s3://[BUCKET_NAME]/