RabbitMQ Producer-Consumer (https://github.com/videlalvaro/php-amqplib)

rabbitmq.consumer.php

<?php

use PhpAmqpLib\Connection\AMQPConnection;
use PhpAmqpLib\Message\AMQPMessage;

// connect
$connection = new AMQPConnection('localhost', 5672, 'guest', 'guest');

// create channel
$channel = $connection->channel();
$channel->queue_declare('flowers', false, true);

// assign job to consumer only if consumer done previous job and it confirmed 
$channel->basic_qos(null, 1, null);

// redister callback
$channel->basic_consume('flowers', '', false, false, false, false, function(AMQPMessage $msg) {
    // print message
    echo 'Received: ' . $msg->body . PHP_EOL;
    
    /* @var $channel \PhpAmqpLib\Channel\AMQPChannel */
    $channel        = $msg->delivery_info['channel'];
    $deliveryTag    = $msg->delivery_info['delivery_tag'];
    
    echo 'Delivery tag: ' . $deliveryTag . PHP_EOL . PHP_EOL;
    
    $channel->basic_ack($deliveryTag);
});

// start loop
echo 'Start loop' . PHP_EOL;
while(count($channel->callbacks)) {
    $channel->wait();
}

rabbitmq.producer.php

<?php

use PhpAmqpLib\Connection\AMQPConnection;
use PhpAmqpLib\Message\AMQPMessage;

// connect
$connection = new AMQPConnection('localhost', 5672, 'guest', 'guest');

// create channel
$channel = $connection->channel();
$channel->queue_declare('flowers', false, true);

// send message
$message = new AMQPMessage('say hello at ' . date('Y-m-d H:i:s'), array(
    'delivery_mode' => 2,
));

$channel->basic_publish($message, '', 'flowers');

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