Symfony Messenger: Cannot Specify DSN x-message-ttl Queue Argument (Integer Expected by RabbitMQ)

[thomaskonrad]

Symfony version(s) affected: 4.1

Description
I'm using the Symfony Messenger component with RabbitMQ and I would like to define a transport DSN with an x-message-ttl queue argument like this:

amqp://<user>:<password>@localhost:5672/%2f/messages?queue[arguments][x-message-ttl]=10000

Now the DSN gets parsed in the Connection::fromDsn function as follows:

if (false === $parsedUrl = parse_url($dsn)) {
    // ...

With parse_url, all URL parameters are represented as strings in the result. What happens when I dispatch a message and RabbitMQ tries to create the exchange and the queue, is the following:

Server channel error: 406, message: PRECONDITION_FAILED - invalid arg 'x-message-ttl' for queue 'messages' in vhost '/': {unacceptable_type,longstr}

RabbitMQ expects an integer, but receives a string (longstr) and is therefore not able to proceed. To confirm that it would work if it were an integer, I attached a debugger and dynamically changed the value to an integer, and it indeed worked.

How to reproduce
Create a new Symfony project, add the Symfony Messenger component via Composer, install a RabbitMQ server, write a simple command that publishes a simple message on a queue, and use amqp://<user>:<password>@localhost:5672/%2f/messages?queue[arguments][x-message-ttl]=10000 as a DSN (with your own credentials).

Possible Solution
The Connection::fromDsn function should try to parse arguments as an integer if they are known to be integer-only (such as x-message-ttl, x-max-length, x-max-length-bytes, and x-max-priority).

[thePanz]

I am working on this during the #SymfonyConHackday2018

[iambrianreich]

I'm migrating an API project over to Symfony 4 and just ran into this myself. To confirm this is ONLY a problem if you specify arguments in the DSN's query string, correct? If I specify my arguments within the transport configuratioin using options/queue/arguments as follows, it seems to work:

framework:
    messenger:
        transports:
            # Uncomment the following line to enable a transport named "amqp"
            my_transport:
                dsn: '%env(MESSENGER_TRANSPORT_DSN)%/my-queue'
                options:
                    queue:
                        arguments:
                            x-max-priority: 255

[thePanz]

I guess so @reichwebconsulting , as the parameter (in your config) is handled as an integer value.

[weaverryan]

I believe this was fixed in #29532