This is also click-changeable in the UI, and seems to not impact running
clusters from some testing.
This gives you a better name than i-asdfasdfasdfasdf.rabbit.lol which is
what you get by default on AWS.
This is mostly seen in logs and rabbitmqctl output.

We'll safely skip the install of rabbitmq if something is already
installed, so warning is sufficient for our purposes.

We're stopping rabbit, but it's part of the configuration the service,
so I didn't use manage:.  We may need to re-discuss the tags (mongo_3_0
works similarly when stopping mongo to manage config).

Files for building a docker container for rabbitmq

All apt-get over https

New third-party repos

Enforce correct rabbit version installed

Flag rabbit upgrading

Adds the CHECK_RABBIT_VERSION flag (true by default). If true and the
rabbitmq version found differs from the version specified in
RABBITMQ_VERSION, the role fails. If false in the same scenario, the
role continues but does not install rabbitmq (because it's already
installed).

This enables us to continue using this role without forcing us to
upgrade rabbitmq.

Rebase miss

Missed merge conflict marker

syntax and whitespace

latest rabbit.

The linked documentation comes out ao .7 for a t2.large
We can also prevent rabbit from going to disk until more memory
is full, but that isn't needed right now.

Rabbit's logs go to /var/log/rabbitmq/ these files are our internal
queue monitoring logs and they will be recreated by
/edx/app/rabbitmq/log-rabbitmq-queues.sh

Without this, we end up with > 10K empty files which makes logrotate and
splunk sad.

Right now these files never go away, and some are a million lines long.
This means splunk eats all the disk IO if we ever restart.

We install the rabbit deb from files.edx.org

I was able to install rabbit and all of its apps at the same
version we have in production without adding the rabbit PPA.

RABBITMQ_CLUSTERED was removed and rabbitmq_clustered_hosts was renamed.

This method relied on the `hostvars` variable provided by ansible to always
be all the nodes in the rabbitmq cluster.  The hostvars var broke as a result
of the upgrade to ansible 1.9 but also even if it did work, this method
required that you always run rabbit plays on the whole cluster.  This is not
reasonable as it makes it very hard to heal a single node that may have fallen
over.

From here on, the RABBITMQ_CLUSTERED_HOSTS var should be used instead to
specify the rabbit hosts that are part of a cluster.