RabbitMQ Cluster in Openshift

This demonstration describes how to create a RabbitMQ cluster in Openshift.

Requirements

1. OpenShift Container Platform v3.6 or newer (we're using this feature).

2. This example is configured to use a PersistentVolume for storing cluster and message data. Thus it is a requirement that Openshift is configured to support Persistent Volumes and that there are PVs with at least ReadWriteOnce (RWO) access available.

3. This example is also using the OpenShift Applier to build and deploy RabbitMQ. As a result you'll need to have ansible installed.

OpenShift objects

The openshift-applier will create the following OpenShift objects:

• A Project named rabbitmq (see files/projects/projects.yml)
• Two ImageStreams rabbitmq and rhel (see files/builds/template.yml and files/imagestreams/images.yml)
• A BuildConfig named rabbitmq (see files/builds/template.yml)
• A RoleBinding named rabbitmq (see files/deployments/template.yml)
• A Service named rabbitmq (see files/deployments/template.yml)
• A StatefulSet named rabbitmq (see files/deployments/template.yml)

Parameters

NAME	DESCRIPTION	VALUE
APPLICATION_NAME	The name for the application	rabbitmq
CONTEXT_DIR	Path within Git project to build	rabbitmq
ERLANG_VERSION	Erlang version to use	20.1.1
FROM_IMAGE	Docker image to build from	rhel7:7.4
RABBITMQ_AUTOCLUSTER_VERSION	RabbitMQ Autocluster version to use	0.10.0
RABBITMQ_VERSION	RabbitMQ version to build	3.6.12
SOURCE_REPOSITORY_REF	Git branch/tag reference	master
SOURCE_REPOSITORY_URL	Git source URI for application	https://github.com/redhat-cop/containers-quickstarts

ERLANG_VERSION, RABBITMQ_VERSION & RABBITMQ_AUTOCLUSTER_VERSION are passed on to the buildconfig thus these versions can be controlled in the build. This is the equivivalent of docker build --build-arg ERLANG_VERSION=19.3.6 to a docker build.

Start build and deploy

1. Clone this repository: git clone https://github.com/redhat-cop/containers-quickstarts
2. cd containers-quickstarts/rabbitmq
3. Run ansible-galaxy install -r requirements.yml --roles-path=roles
4. Login to Openshift: oc login -u <username> https://master.example.com:8443
5. Run openshift-applier: ansible-playbook -i inventory/hosts roles/openshift-applier/playbooks/openshift-cluster-seed.yml

Verify your pods are running

$ oc get pod -n rabbitmq
NAME               READY     STATUS      RESTARTS   AGE
rabbitmq-0         1/1       Running     0          1m
rabbitmq-1         1/1       Running     0          1m
rabbitmq-1-build   0/1       Completed   0          1m
rabbitmq-2         1/1       Running     0          1m

Verify your RabbitMQ Cluster

$ oc rsh -n rabbitmq rabbitmq-1 rabbitmqctl cluster_status
Cluster status of node '[email protected]'
[{nodes,[{disc,['[email protected]','[email protected]',
                '[email protected]']}]},
 {running_nodes,['[email protected]','[email protected]','[email protected]']},
 {cluster_name,<<"[email protected]">>},
 {partitions,[]},
 {alarms,[{'[email protected]',[]},
          {'[email protected]',[]},
          {'[email protected]',[]}]}]

Tear everything down

oc delete project rabbitmq