kubernetes-rabbitmq-cluster

A ready to deploy rabbitmq cluster to work on top of Kubernetes.

It uses rabbitmq clusterer plugin to achieve clustering.

Requirements:

1. Kubernetes version 1.5.X (We're using StatefulSet)
2. kubectl configured to work with your Kubernetes API
3. Tested on Kubernetes 1.5.2 on top of AWS (See future work)
4. Optional - Access to your own docker repository to store your own images. That's relevant if you don't want to use the default images offered here.

Contents:

1. A 3 nodes rabbitmq cluster as StatefulSet
2. A rmq-cluster headless service to control the StatefulSet domain
3. a rabbitmq service to access the cluster
4. An optional, rabbitmq-management service to access the admin control panel

Environment Variables:

Name	Default Value	Purpose
NAMESPACE	default	Change it if you want to create the RabbitMQ cluster in a custom Kubernetes namespace. If the namespace does not exist in the moment of deployment, it will be created for you.
DOCKER_REPOSITORY	nanit	Change it if you want to build and use custom docker repository
SUDO	sudo	Should docker commands be prefixed with sudo. Change to "" to omit sudo.
RBAC	FALSE	Should create a role/system account and role binding
RABBITMQ_REPLICAS	3	Number of nodes in the cluster
RABBITMQ_DEFAULT_USER	None	The default username to access the management console
RABBITMQ_DEFAULT_PASS	None	The default password to access the management console
RABBITMQ_ERLANG_COOKIE	None	Erlang secret needed for nodes communication
RABBITMQ_EXPOSE_MANAGEMENT	FALSE	Should RMQ management console be exposed as a service
RABBITMQ_MANAGEMENT_SERVICE_TYPE	LoadBalancer	Kubernetes service type for the management console
RABBITMQ_HA_POLICY	None	Set this variable to automatically set HA policy on all queues
RABBITMQ_LOG_LEVEL	info	Log levels are set for all RabbitMQ log types: connection, mirroring, channel and federation. Valid values are: none, error, warning, info, debug
RABBITMQ_ADDITIONAL_YAML	""	Inject additional arbitrary YAML into the stateful set

Deployment:

1. Clone this repository
2. Run:

export NAMESPACE=default && \
export DOCKER_REPOSITORY=nanit && \
export RABBITMQ_REPLICAS=5 && \
export RABBITMQ_DEFAULT_USER=username && \
export RABBITMQ_DEFAULT_PASS=password && \
export RABBITMQ_ERLANG_COOKIE=secret && \
export RABBITMQ_EXPOSE_MANAGEMENT=TRUE && \
export RABBITMQ_MANAGEMENT_SERVICE_TYPE=LoadBalancer && \
export RABBITMQ_HA_POLICY='{\"ha-mode\":\"all\"}' && \
export RABBITMQ_LOG_LEVEL=info && \
export RABBITMQ_ADDITIONAL_YAML="" && \
export SUDO="" && \
make deploy

Usage:

At the end of the installation you should have a service named rabbitmq which you can use to connect to the cluster. If you've set the environment variable RABBITMQ_HA_POLICY a policy named ha-all is created to match all queues. These are the resource you're supposed to see on the cluster when running kubectl get pods,svc:

Please note the following:

1. The number of rabbitmq pods may be different in case you chose a different number of RABBITMQ_REPLICAS than 5
2. The rabbitmq-management service will only be available if you've set RABBITMQ_EXPOSE_MANAGEMENT to TRUE

Changing the number of nodes:

Number of nodes is configurable with RABBITMQ_REPLICAS environment variable. Note that changing the number of nodes after the initial deployment of the cluster is problematic since old rabbitmq instance won't fetch the new nodes hosts into the clusterer.config file.

For now, the best option is to:

1. Delete the current statefulset with kubectl delete statefulset rabbitmq
2. Re-deploy the cluster with the new RABBITMQ_REPLICAS value

Building your own images:

If you want to build use your own images make sure to change the DOCKER_REPOSITORY environment variable to your own docker repository. It will build the images, push them to your docker repository and use them to create all the needed kubernetes deployments.

Docker Compose:

You can run the same setup in docker-compose using

$ docker-compose build && docker-compose up

Then, go to localhost:15672 and you'll see the cluster is already formed up.

Future work:

1. Allow setting a different number of replicas