[BridgeDoctrineMessenger] Doctrine ping connection middleware

[insidestyles]

Q	A
Branch?	master
Bug fix?	no
New feature?	yes
BC breaks?	no
Deprecations?	no
Tests pass?	yes
Fixed tickets	#...
License	MIT
Doc PR	symfony/symfony-docs#...

• Check and reconnect if mysql has gone away:

    <service id="messenger.middleware.doctrine_ping_connection" class="Symfony\Bridge\Doctrine\Messenger\DoctrinePingConnectionMiddleware" public="false">
        <argument type="service" id="doctrine" />
    </service>
  

• Close and save opened connections (not active worker):

    <service id="messenger.middleware.doctrine_close_connection" class="Symfony\Bridge\Doctrine\Messenger\DoctrineCloseConnectionMiddleware" public="false">
        <argument type="service" id="doctrine" />
    </service>
  

[nicolas-grekas]

CS-related comments only :)

[sroze]

It's a good idea. One simple comment.

Also, can you open a WIP pull-request on the DoctrineBundle as well so the service messenger.middleware.doctrine_ping_connection would be available by default? Maybe we should provide two services with the different values of forceCloseConnection?

[sroze]

You don't need this default value as it's given by the constructor.

[insidestyles]

As you said, I think that creating 2 separated middlewares is better. Is it ok?

[sroze]

As long as it’s clear in your documentation PR I think it’s okay 👍

[sroze]

@insidestyles what I meant is only one class here but two service definitions within the DoctrineBundle where you need to register the services (in the messenger.xml).

[insidestyles]

@insidestyles what I meant is only one class here but two service definitions within the DoctrineBundle where you need to register the services (in the messenger.xml).

I understood. Should I revert the last commit?

I also created doctrine/DoctrineBundle#956

[alcaeus]

@sroze what Symfony version are you targeting with this? Is this still eligible for 4.3 or will this land in 4.4 by default?

[fabpot]

I will stop merging new features for 4.3 probably at the end of the week. But I would really like this one to be part of 4.3 :) We need some approvals.

[sroze]

Can you add a note in the CHANGELOG as well as the @experimental in 4.3 annotation on the two classes, please?

[insidestyles]

Can you add a note in the CHANGELOG as well as the @experimental in 4.3 annotation on the two classes, please?

@sroze Done.

[sroze]

Thank you @insidestyles.