Add tag with autocluster plugin

[Fank]

Currently only a tag with the management plugin exists.
There should be a tag that also contains the autocluster plugin currently it only supports ubuntu base not alpine (tested 0.8.0).

[Gsantomaggio]

@Fank please read this #121
We already spoke about it

[michaelklishin]

@Fank there is at least one separate image that includes rabbitmq-autocluster. I really doubt this project should integrate
rabbitmq-autocluster further and advertise it as a first-class "feature" for a few reasons:

• It supports N backends, some of which have enough configurable settings to look scary
• Starting with 3.7.0, that plugin will be partially in RabbitMQ core, partially in separate backend plugins such as rabbitmq-peer-discovery-consul
• A separate image can build on top of this one.

[Fank]

Thanks havn't found it.

[Fank]

Yea but if 3.7 gets released this should be enabled by default, i saw that multiple person are in need of this one.

[michaelklishin]

@Fank please spend sometime figuring out what will be available in 3.7.0 around cluster formation. It is not a single "feature" and I really don't think it should be advertised or implemented as such in this image. It can be N features or N new images.

[michaelklishin]

@Gsantomaggio @tianon FWIW maybe it's the place where this image's plans w.r.t. cluster formation features in 3.7.0 can be discussed.

[tianon]

@michaelklishin yeah, that sounds sane!

Just to get things started, I used the following diff to get something built so I could start playing around:

diff --git a/3.6/debian/Dockerfile b/3.6/debian/Dockerfile
index 7a8cfc9..734b63a 100644
--- a/3.6/debian/Dockerfile
+++ b/3.6/debian/Dockerfile
@@ -63,10 +63,10 @@ RUN set -ex; \
        gpg --export "$key" > /etc/apt/trusted.gpg.d/rabbitmq.gpg; \
        rm -rf "$GNUPGHOME"; \
        apt-key list
-RUN echo 'deb http://www.rabbitmq.com/debian testing main' > /etc/apt/sources.list.d/rabbitmq.list
+RUN echo 'deb http://dl.bintray.com/rabbitmq/debian-dev stretch rabbitmq-server-v3.7.x' > /etc/apt/sources.list.d/rabbitmq.list
 
-ENV RABBITMQ_VERSION 3.6.11
-ENV RABBITMQ_DEBIAN_VERSION 3.6.11-1
+ENV RABBITMQ_VERSION 3.7.0-alpha.380
+ENV RABBITMQ_DEBIAN_VERSION 3.7.0~alpha.380-1
 
 RUN apt-get update && apt-get install -y --no-install-recommends \
                rabbitmq-server=$RABBITMQ_DEBIAN_VERSION \

One of the first issues I ran into is that rabbitmq-plugins list ... now requires the server to be online (unlike ...-plugins enable and disable, which can optionally be performed offline, and how list used to be). There must be some new way to check whether the management plugin is enabled?

Other than that issue, everything appears to start up correctly. 😄

[michaelklishin]

@tianon yes, rabbitmq-plugins in 3.7.0 performs more validations. That particular one can be dropped, I guess, or --offline should be supported by list. I filed rabbitmq/rabbitmq-cli#219.

It is safe to enable rabbitmq_management with --offline even if it's already enabled. Plugin activation should be idempotent. Would this work for this image?

[michaelklishin]

@tianon rabbitmq/rabbitmq-cli#220, will be in a new 3.7.0 milestone we hope to publish in a couple of days.

[tianon]

Very nice! 🤘

It's used in the entrypoint script to detect whether or not management is enabled so that we can generate appropriate configuration for it conditionally. In the Dockerfile, we already use --offline: 😄

rabbitmq/3.6/debian/management/Dockerfile

Line 3 in 42d8deb

RUN rabbitmq-plugins enable --offline rabbitmq_management