How to run RabbitMQ with PHP

Before you go any further in this article, be sure to get started with a free RabbitMQ plan at CloudAMQP. to be able to easily follow along.

PHP is a popular server-side scripting language with an officially recognized RabbitMQ library. The php-amqplib package is a pure PHP implementation of the AMQP 0.9.1 protocol. In this article, we will show how to install and use php-amqplib through a RabbitMQ PHP example.

Installing amqp-lib

A PHP package manager is required to install amqp-lib. This tutorial uses Composer as the package manager.

Install the package manager using the directions on their website and run:

composer require php-amqplib/php-amqplib

Composer installed amqp-lib to your vendor folder. Open your favorite editor to start building your PHP application.

Publishing to RabbitMQ

The amqp-lib library implements the AMQP protocol. As a barebones implementation, there are no additional features. You must create publishers and subscribers from scratch.

Create an exchange and a queue and publish a message as follows:

<?php
  require('vendor/autoload.php');
  use PhpAmqpLib\Connection\AMQPStreamConnection;
  use PhpAmqpLib\Connection\AMQPSSLConnection;
  use PhpAmqpLib\Message\AMQPMessage;
  
  $url_str = getenv('CLOUDAMQP_URL')
    or exit("CLOUDAMQP_URL not set");
  $url = parse_url($url_str);
  $vhost = substr($url['path'], 1);

  if($url['scheme'] === "amqps") {
    $ssl_opts = array(
      'capath' => '/etc/ssl/certs'
    );
    $connection = new AMQPSSLConnection($url['host'], 5671, $url['user'], $url['pass'], $vhost, $ssl_opts);
  } else {
    $connection = new AMQPStreamConnection($url['host'], 5672, $url['user'], $url['pass'], $vhost);
  }

  $channel = $connection->channel();

  $channel->exchange_declare('test_exchange', 'direct', false, false, false);
  $channel->queue_declare('test_queue', false, false, false, false);
  $channel->queue_bind('test_queue', 'test_exchange', 'test_key');

  $msg = new AMQPMessage('Hello World!');
  $channel->basic_publish($msg, 'test_exchange', 'test_key');

  echo " [x] Sent 'Hello World!' to test_exchange / test_queue.\n";

  $channel->close();
  $connection->close();
?>

We created the test_exchange and bound the test_queue to the exchange using the routing key test_key. We also sent a basic "hello world" message to the queue.

Consuming from RabbitMQ

With our test message in test_queue, we should next create a consumer that prints our message to the console. Subscribe to test_queue and process the message as follows:

<?php
  require('vendor/autoload.php');
  use PhpAmqpLib\Connection\AMQPStreamConnection;
  use PhpAmqpLib\Connection\AMQPSSLConnection;
  use PhpAmqpLib\Message\AMQPMessage;

  $url = parse_url(getenv('CLOUDAMQP_URL'));
  $vhost = substr($url['path'], 1);

  if($url['scheme'] === "amqps") {
    $ssl_opts = array(
        'capath' => '/etc/ssl/certs'
    );
    $connection = new AMQPSSLConnection($url['host'], 5671, $url['user'], $url['pass'], $vhost, $ssl_opts);
  } else {
    $connection = new AMQPStreamConnection($url['host'], 5672, $url['user'], $url['pass'], $vhost);
  }

  $channel = $connection->channel();

  $callback = function ($msg) {
    echo ' [x] Received ', $msg->body, "\n";
  };

  $channel->basic_consume('test_queue', '', false, true, false, false, $callback);

  while ($channel->is_consuming()) {
    $channel->wait();
  }

  $channel->close();
  $connection->close();
?>

The "hello world" message should appear in your console. We now have a working RabbitMQ publisher-subscriber model.

Connecting to CloudAMQP in PHP

CloudAMQP is a fully-managed RabbitMQ broker. As such, these examples showed you how to send and receive messages using php-amqplib and your cloud broker. To connect to CloudAMQP, replace the URLs in the examples with your CloudAMQP URL.