New style config format support

[michaelklishin]

This is an umbrella issue that's related to #442, #496 and some general ideas about what 6.0 and the new style config format support might look like. It will be updated with details as the thinking around those topics solidifies.

Problem Statement

This cookbook has been around since 2009 and is currently very much centered not only around the classic config format but also environment variables, which are not deprecated but also no longer recommended when other means (namely the config file) are an option.

We'd like to support the new style config format, including the advanced.config part, but also keep a way to use rabbitmq.config as a stop gap measure even though 6.0 will target RabbitMQ 3.7.x only.

[jakauppila]

@michaelklishin Is there any timelines for this support or direction on how it should be implemented? We are looking to move our Windows-based clusters to Linux and will be using Chef to provision, so there may be opportunities for us to do some development of this support.

[michaelklishin]

@jakauppila I have some semi-baked thoughts but very little time to dedicate to the cookbook. I'd be happy to discuss them, be it on the mailing list or Zoom/similar.

The very first step is to make it possible to override target config file name via attributes. Then we can switch it to advanced.config for 3.7.x, which should work with latest 3.7.x releases even when rabbitmq.conf is not present.

From there it's mostly a gradual migration of more and more configurable settings from the advanced.config to rabbitmq.conf (and some settings are not supported by the ini-style format).

I also think it would be nice to support arbitrary snippets for both config formats (it is particularly easy with the new style config).

[michaelklishin]

@jakauppila if you have a specific timeline on your migration, please contact me directly via Pivotal email. There's a chance I can get some initial things in place around xmas so it would be easier to contribute.

[jakauppila]

@michaelklishin I'll throw some thoughts together and post to the mailing list in case anyone else has any input.

I may focus on the arbitrary snippet support for both formats as that would probably get us to where we need the fastest. At this point I think we want more of a direction by the end of Q1 with a target of being done migrating by the end of Q2 2019.

I may start playing around with the cookbook some next week.

[jakauppila]

@michaelklishin Put together a few notes at https://groups.google.com/forum/#!topic/rabbitmq-users/SzFPTPYal_g

[misale]

is there any update on this enhancement ?

[michaelklishin]

There are no updates. When stories are worked on, they are mentioned in PRs and commits, so it would be easy to see.