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Manage RabbitMQ with KubeBlocks

RabbitMQ is a reliable and mature messaging and streaming broker, which is easy to deploy on cloud environments, on-premises, and on your local machine.

KubeBlocks supports the management of RabbitMQ. This tutorial illustrates how to create and manage a Qdrant cluster by kubectl and YAML files. You can find more YAML examples in the GitHub repository.

Before you start​

Create a cluster​

KubeBlocks implements a Cluster CRD to define a cluster. Here is an example of creating a RabbitMQ cluster with three replicas. Pods are distributed on different nodes by default. But if you only have one node for a cluster with three replicas, configure the cluster affinity by setting spec.schedulingPolicy or spec.componentSpecs.schedulingPolicy. For details, you can refer to the API docs. But for a production environment, it is not recommended to deploy all replicas on one node, which may decrease the cluster availability.

cat <<EOF | kubectl apply -f -
apiVersion: apps.kubeblocks.io/v1
kind: Cluster
metadata:
  name: mycluster
  namespace: demo
spec:
  terminationPolicy: Delete
  componentSpecs:
    - name: rabbitmq
      componentDef: rabbitmq
      serviceVersion: 3.13.7
      serviceAccountName: kb-rabbitmq-cluster
      replicas: 3
      resources:
        limits:
          cpu: "0.5"
          memory: "0.5Gi"
        requests:
          cpu: "0.5"
          memory: "0.5Gi"
      volumeClaimTemplates:
        - name: data
          spec:
            storageClassName: ""
            accessModes:
              - ReadWriteOnce
            resources:
              requests:
                storage: 20Gi
---
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: rabbitmq-cluster-peer-discovery
  namespace: demo
rules:
- apiGroups:
  - ""
  resources:
  - endpoints
  verbs:
  - get
- apiGroups:
  - ""
  resources:
  - events
  verbs:
  - create
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: kb-rabbitmq-cluster
  namespace: demo
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: kb-rabbitmq-cluster
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: rabbitmq-cluster-peer-discovery
subjects:
  - kind: ServiceAccount
    name: kb-rabbitmq-cluster
    namespace: demo
EOF
FieldDefinition
spec.terminationPolicyIt is the policy of cluster termination. Valid values are DoNotTerminate, Delete, WipeOut. For the detailed definition, you can refer to Termination Policy.
spec.componentSpecsIt is the list of ClusterComponentSpec objects that define the individual Components that make up a Cluster. This field allows customized configuration of each component within a cluster.
spec.componentSpecs.serviceVersionIt specifies the version of the Service expected to be provisioned by this Component. Valid options are [3.10.25,3.11.28,3.12.14,3.13.2,3.13.7,3.8.14,3.9.29].
spec.componentSpecs.serviceAccountNameIt specifies the name of the ServiceAccount required by the running Component. RabbitMQ needs the peer-discovery role to create events and get endpoints. This is essential for discovering other RabbitMQ nodes and forming a cluster.
spec.componentSpecs.replicasIt specifies the number of replicas of the component. RabbitMQ prefers ODD numbers like [3, 5, 7]. All data/state is replicated across all replicas.
spec.componentSpecs.resourcesIt specifies the resources required by the Component.
spec.componentSpecs.volumeClaimTemplatesIt specifies a list of PersistentVolumeClaim templates that define the storage requirements for the Component.
spec.componentSpecs.volumeClaimTemplates.nameIt refers to the name of a volumeMount defined in componentDefinition.spec.runtime.containers[*].volumeMounts.
spec.componentSpecs.volumeClaimTemplates.spec.storageClassNameIt is the name of the StorageClass required by the claim. If not specified, the StorageClass annotated with storageclass.kubernetes.io/is-default-class=true will be used by default.
spec.componentSpecs.volumeClaimTemplates.spec.resources.storageYou can set the storage size as needed.

For more API fields and descriptions, refer to the API Reference.

KubeBlocks operator watches for the Cluster CRD and creates the cluster and all dependent resources. You can get all the resources created by the cluster with kubectl get all,secret,rolebinding,serviceaccount -l app.kubernetes.io/instance=mycluster -n demo.

kubectl get all,secret,rolebinding,serviceaccount -l app.kubernetes.io/instance=mycluster -n demo

Run the following command to see the created RabbitMQ cluster object:

kubectl get cluster mycluster -n demo -o yaml

Connect to the cluster​

Use the RabbitMQ tools to connect to and manage the RabbitMQ cluster.

Scale​

Scale vertically​

Before you start, check whether the cluster status is Running. Otherwise, the following operations may fail.

kubectl get cluster mycluster -n demo
>
NAME        CLUSTER-DEFINITION    VERSION        TERMINATION-POLICY     STATUS    AGE
mycluster                                        Delete                 Running   47m

Steps​

  1. Apply an OpsRequest to the specified cluster. Configure the parameters according to your needs.

    kubectl apply -f - <<EOF
    apiVersion: apps.kubeblocks.io/v1alpha1
    kind: OpsRequest
    metadata:
      name: ops-vertical-scaling
      namespace: demo
    spec:
      clusterName: mycluster
      type: VerticalScaling
      verticalScaling:
      - componentName: rabbitmq
        requests:
          memory: "2Gi"
          cpu: "1"
        limits:
          memory: "4Gi"
          cpu: "2"
    EOF

  2. Check the operation status to validate the vertical scaling.

    kubectl get ops -n demo
    >
    NAME                   TYPE              CLUSTER     STATUS    PROGRESS   AGE
    ops-vertical-scaling   VerticalScaling   mycluster   Succeed   3/3        6m

    If an error occurs, you can troubleshoot it with kubectl describe ops -n demo command to view the events of this operation.

  3. Check whether the corresponding resources change.

    kubectl describe cluster mycluster -n demo

Scale horizontally​

Horizontal scaling changes the amount of pods. For example, you can scale out replicas from three to five.

From v0.9.0, besides replicas, KubeBlocks also supports scaling in and out instances, refer to the Horizontal Scale tutorial for more details and examples.

Before you start, check whether the cluster status is Running. Otherwise, the following operations may fail.

kubectl get cluster mycluster -n demo
>
NAME        CLUSTER-DEFINITION    VERSION        TERMINATION-POLICY     STATUS    AGE
mycluster                                        Delete                 Running   47m

Steps​

  1. Apply an OpsRequest to a specified cluster. Configure the parameters according to your needs.

    The example below means deleting two replicas.

    kubectl apply -f - <<EOF
    apiVersion: apps.kubeblocks.io/v1alpha1
    kind: OpsRequest
    metadata:
      name: ops-horizontal-scaling
      namespace: demo
    spec:
      clusterName: mycluster
      type: HorizontalScaling
      horizontalScaling:
      - componentName: rabbitmq
        scaleIn:
          replicaChanges: 2
    EOF

    If you want to scale in replicas, replace scaleOut with scaleIn and change the value in replicaChanges.

  2. Check the operation status to validate the horizontal scaling status.

    kubectl get ops -n demo
    >
    NAME                     TYPE                CLUSTER     STATUS    PROGRESS   AGE
    ops-horizontal-scaling   HorizontalScaling   mycluster   Succeed   2/2        6m

    If an error occurs, you can troubleshoot it with kubectl describe ops -n demo command to view the events of this operation.

  3. Check whether the corresponding resources change.

    kubectl describe cluster mycluster -n demo

Volume expansion​

Before you start, check whether the cluster status is Running. Otherwise, the following operations may fail.

kubectl get cluster mycluster -n demo
>
NAME        CLUSTER-DEFINITION    VERSION        TERMINATION-POLICY     STATUS    AGE
mycluster                                        Delete                 Running   47m

  1. Change the value of storage according to your need and run the command below to expand the volume of a cluster.

    kubectl apply -f - <<EOF
    apiVersion: apps.kubeblocks.io/v1alpha1
    kind: OpsRequest
    metadata:
      name: ops-volume-expansion
      namespace: demo
    spec:
      clusterName: mycluster
      type: VolumeExpansion
      volumeExpansion:
      - componentName: rabbitmq
        volumeClaimTemplates:
        - name: data
          storage: "40Gi"
    EOF

  2. Validate the volume expansion operation.

    kubectl get ops -n demo
    >
    NAME                   TYPE              CLUSTER     STATUS    PROGRESS   AGE
    ops-volume-expansion   VolumeExpansion   mycluster   Succeed   1/1        6m

    If an error occurs, you can troubleshoot it with kubectl describe ops -n demo command to view the events of this operation.

  3. Check whether the corresponding cluster resources change.

    kubectl describe cluster mycluster -n demo

Restart​

  1. Restart a cluster.

    kubectl apply -f - <<EOF
    apiVersion: apps.kubeblocks.io/v1alpha1
    kind: OpsRequest
    metadata:
      name: mycluster-restart
      namespace: demo
    spec:
      clusterName: mycluster
      type: Restart 
      restart:
      - componentName: rabbitmq
    EOF

  2. Check the pod and operation status to validate the restarting.

    kubectl get pod -n demo

    kubectl get ops -n demo

    During the restarting process, there are two status types for pods.

    • STATUS=Terminating: it means the cluster restart is in progress.
    • STATUS=Running: it means the cluster has been restarted.

Stop/Start a cluster​

You can stop/start a cluster to save computing resources. When a cluster is stopped, the computing resources of this cluster are released, which means the pods of Kubernetes are released, but the storage resources are reserved. You can start this cluster again by snapshots if you want to restore the cluster resources.

Stop a cluster​

Run the command below to stop a cluster.

kubectl apply -f - <<EOF
apiVersion: apps.kubeblocks.io/v1alpha1
kind: OpsRequest
metadata:
  name: mycluster-stop
  namespace: demo
spec:
  clusterName: mycluster
  type: Stop
EOF

Start a cluster​

Run the command below to start a cluster.

kubectl apply -f - <<EOF
apiVersion: apps.kubeblocks.io/v1alpha1
kind: OpsRequest
metadata:
  name: mycluster-start
  namespace: demo
spec:
  clusterName: mycluster
  type: Start
EOF

Delete a cluster​

Termination policy​

note

The termination policy determines how a cluster is deleted.

terminationPolicyDeleting Operation
DoNotTerminateDoNotTerminate prevents deletion of the Cluster. This policy ensures that all resources remain intact.
DeleteDelete deletes Cluster resources like Pods, Services, and Persistent Volume Claims (PVCs), leading to a thorough cleanup while removing all persistent data.
WipeOutWipeOut is an aggressive policy that deletes all Cluster resources, including volume snapshots and backups in external storage. This results in complete data removal and should be used cautiously, primarily in non-production environments to avoid irreversible data loss.

To check the termination policy, execute the following command.

kubectl get cluster mycluster -n demo
>
NAME        CLUSTER-DEFINITION    VERSION        TERMINATION-POLICY     STATUS    AGE
mycluster                                        Delete                 Running   55m

Steps​

Run the command below to delete a specified cluster.

kubectl delete -n demo cluster mycluster

If you want to delete a cluster and its all related resources, you can modify the termination policy to WipeOut, then delete the cluster.

kubectl patch -n demo cluster mycluster -p '{"spec":{"terminationPolicy":"WipeOut"}}' --type="merge"

kubectl delete -n demo cluster mycluster