rabbitmq

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
• Two ImageStreams rabbitmq and ubi (see .openshift/templates/builds/template.yml and .openshift/templates/imagestreams/images.yml)
• A BuildConfig named rabbitmq (see .openshift/templates/builds/template.yml)
• A RoleBinding named rabbitmq (see .openshift/templates/deployments/template.yml)
• A Service named rabbitmq (see .openshift/templates/deployments/template.yml)
• A ConfigMap named rabbitmq-config(see .openshift/templates/configmaps/config.yml)
• A StatefulSet named rabbitmq (see .openshift/templates/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	22.1.4
FROM_IMAGE	Docker image to build from	ubi:7.7
RABBITMQ_VERSION	RabbitMQ version to build	3.8.0
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 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.

Deploying

Helm chart

1. Clone this repository: git clone https://github.com/redhat-cop/containers-quickstarts
2. cd containers-quickstarts/rabbitmq
3. oc new-project rabbitmq
4. helm install rabbitmq chart

NOTE: This image is currently not compatible with https://github.com/bitnami/charts/tree/master/bitnami/rabbitmq but this might change in the future.

Build and deploy using Openshift Applier

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 .applier/ 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 rabbitmq-1 rabbitmqctl cluster_status --formatter json | tail -1 | jq '{"alarms": .alarms,"running_nodes": .running_nodes,"versions": .versions}'
{
  "alarms": [],
  "running_nodes": [
    "rabbit@rabbitmq-2.rabbitmq.rabbitmq.svc.cluster.local",
    "rabbit@rabbitmq-0.rabbitmq.rabbitmq.svc.cluster.local",
    "rabbit@rabbitmq-1.rabbitmq.rabbitmq.svc.cluster.local"
  ],
  "versions": {
    "rabbit@rabbitmq-0.rabbitmq.rabbitmq.svc.cluster.local": {
      "erlang_version": "22.1.4",
      "rabbitmq_version": "3.8.0"
    },
    "rabbit@rabbitmq-1.rabbitmq.rabbitmq.svc.cluster.local": {
      "erlang_version": "22.1.4",
      "rabbitmq_version": "3.8.0"
    },
    "rabbit@rabbitmq-2.rabbitmq.rabbitmq.svc.cluster.local": {
      "erlang_version": "22.1.4",
      "rabbitmq_version": "3.8.0"
    }
  }
}

Testing

This quickstart is using bats for unit and acceptance testing of the included Helm chart.

Unit testing

The unit tests will test features of the Helm chart and also requires yq.

bats test/unit
 ✓ configmap: three config files defined
 ✓ rolebinding: default serviceaccount
 ✓ rolebinding: custom serviceaccount
 ✓ service: enabled by default
 ✓ service: name match release name
...
 ✓ statefulset: default tolerations
 ✓ statefulset: custom tolerations

41 tests, 0 failures

Acceptance testing

The acceptance tests will deploy the RabbitMQ cluster using the Helm chart and assumes you have access to an OpenShift cluster (v3.11+) with at least self-provisioner access (it will create a new namespace). You will also need to install jq and at the moment you will need to use Bats from the master branch as the test require features added after the latest Bats' release.

bats test/acceptance
 ✓ rabbitmq/ha: should have 'hostname' package installed
 ✓ rabbitmq/ha: should have $LANG set to 'en_US.UTF-8'
 ✓ rabbitmq/ha: should not have any alarms
 ✓ rabbitmq/ha: fail if number of replicas aren't ready
 ✓ rabbitmq/ha: should run on different cluster nodes
 ✓ rabbitmq/ha: should have a three node cluster

6 tests, 0 failures

Tear everything down

helm uninstall rabbitmq or oc delete project rabbitmq