README

A Symfony Messenger transport on MongoDB, on top of facile-it/mongodb-bundle

Installation

• To install this package, use Composer:

composer require facile-it/mongodb-messenger-transport

This package register itself as a bundle inside Symfony; you have to have both it and the FacileMongoDbBundle enabled, if you hadn't it before. To do it, you either:

• let Flex enable it automatically, if you're using it:

# config/bundles.php

# ...
    Facile\MongoDbBundle\FacileMongoDbBundle::class => ['all' => true],
+     Facile\MongoDbMessenger\FacileMongoDbMessengerBundle::class => ['all' => true],
];

• Enable it yourself in your kernel:

<?php

class Kernel extends BaseKernel
{
    public function registerBundles(): array
    {
        return [
            new Symfony\Bundle\FrameworkBundle\FrameworkBundle(),
            # ...
            new Facile\MongoDbBundle\FacileMongoDbBundle(),
+            new Facile\MongoDbMessenger\FacileMongoDbMessengerBundle(),
        ];
    }
}

Configuration

1. If you haven't already, configure the MongoDB connection following instructions for facile-it/mongodb-bundle
2. Using the connection name from that configuration (i.e. default in the Flex recipe), configure a new transport for the Messenger like this:

# config/packages/messenger.yaml
framework:
  messenger:
    transports:
      new_transport: 'facile-it-mongodb://default'

Note: when using it for the first time, or when calling the messenger:setup-transports console command, this transport creates the collection with an index for optimal performances, since it's tailored to the properties that are used to retrieve the messages.

Suggestions

It's suggested to use this transport for failed messages, like the Doctrine one; if you want to do that, you can do it like this:

framework:
  messenger:
    failure_transport: new_transport
    transports:
      new_transport: 'facile-it-mongodb://default'

If you configure this transport multiple times, remember to use the queue_name and/or the collection_name options (see below) to differentiate the messages.

Full configuration reference

This transport, like other default ones, has a number of options available, which can be passed as a query string in the DSN, or as an array below, like in the following example (all values are the provided defaults):

framework:
  messenger:
    transports:
      new_transport: 
        dsn: 'facile-it-mongodb://default'
        options:
          collection_name: 'messenger_messages'
          queue_name: 'default'
          redeliver_timeout: 3600
          document_enhancers: [] 

The redeliver_timeout option

The redeliver_timeout works in the same way as the DoctrineTransport: when a message is delivered but not acked nor rejected (maybe due to a fatal crash or a network failure), it works as a timeout, and makes the message redeliverable after it expires.

The document_enhancers option

The document_enhancers option is an extension point of this transport; it accepts an array of strings, each of them a fully qualified class name or a service name with the @ prefix.

It allows the end user to add fields to the document that will be persisted for each message. Each enhancer has to implement the Facile\MongoDbMessenger\Extension\DocumentEnhancer interface, which requires the implementation of a enhance(BSONDocument $document, Envelope $envelope): void method. The BSONDocument will be persisted afterwards, and it can be enriched with additional properties, which can be useful for searching and indexing for specific information with i.e. MongoDbTransport::find.

You can take a look at the provided \Facile\MongoDbMessenger\Extension\DocumentEnhancer\LastErrorMessageEnhancer as an example, or use it like this:

framework:
  messenger:
    transports:
      new_transport: 
        dsn: 'facile-it-mongodb://default'
        options:
          document_enhancers:
          - 'Facile\MongoDbMessenger\Extension\DocumentEnhancer\LastErrorMessageEnhancer'
          # or
          - '@my_document_enhancer'

services:
  my_document_enhancer:
    class: App\My\Class # which implements the DocumentEnhancer interface
    arguments:
    - '...'