RabbitMQ 4.0 compatibility

[LoisSotoLopez]

Tested against rabbitmq/rabbitmq-server@8268a11

Fixes #112

[noxdafox]

Hello,

this breaks backwards compatibility with RMQ 3.X which we need to support for the foreseeable future.

[noxdafox]

Are changes to this file intentional or have they been included by mistake? You can instruct git to ignore changes to a file by doing: git update-index --assume-unchanged rabbitmq-components.mk.

[gomoripeti]

this is indeed by mistake. I myself never looked at the content of the erlang.mk and rabbitmq-components.mk and assumed they have the "usual" content instead of a dynamic bootstrap Makefile.

[gomoripeti]

hi @noxdafox

The few community plugins Im familiar with that are maintained by the Core Team have the logic that there is a new version for every minor RabbitMQ version. While this might not be necessary if there is no code change needed between major/minor versions, 3.13 did need a new version of the dedup plugin (message containers - #109 was not backwards compatible either) and 4.0 needs code change again. So 3.x can be supported by different versions of the plugin:

• 0.6.2 works with 3.12
• 0.6.3 works with 3.13
• next version works with 4.0

It is possible to branch out, and 0.7.x works with 4.0 and 0.6.3+ can be patched further for 3.13.

Alternatively this PR can be made backwards compatible by keeping the removed versions of the callback functions around.

[noxdafox]

RMQ 4.0.0 is a major, non-backwards compatible release. It will take quite a bit of time before users migrate to the new version as HA/Mirror queues are in widespread use and migrate them to Quorum ones will take time.

Therefore, it's better if we support 3.13.x for a while as several organizations will upgrade to the last 3.x version before doing the migration.

This shall be very simple in this case as the only necessary thing to do is to maintain both function signatures for a while.

[LoisSotoLopez]

Not sure about this syntax or whether that's an adequate config for the project. I just set the value that allowed me to enable the plugin on my manual tests (enabling the plugin).

[noxdafox]

Thanks! Will test these changes and make a new release.

[gomoripeti]

just wondering if the change was not tested yet (maybe because of lack of time which is totally understandable) or tagging a new release was only accidentally forgotten? (or maybe there are build issues again, I can try to help in that case)

[noxdafox]

Slowly testing. Time is little. I will see if I can make a release this weekend.

[noxdafox]

New release is out. Thanks for the contribution!

[gomoripeti]

thank you for the release!