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Update version of Redis Cluster

This guide will show you how to use KubeDB Enterprise operator to update the version of Redis cluster.

Before You Begin

• At first, you need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. If you do not already have a cluster, you can create one by using kind.

• Install KubeDB Community and Enterprise operator in your cluster following the steps here.

• You should be familiar with the following KubeDB concepts:

  • Redis
  • Redis Clustering
  • RedisOpsRequest
  • Upgrading Overview

To keep everything isolated, we are going to use a separate namespace called demo throughout this tutorial.

$ kubectl create ns demo
namespace/demo created

Note: YAML files used in this tutorial are stored in docs/examples/redis directory of kubedb/docs repository.

Prepare Redis Cluster Database

Now, we are going to deploy a Redis cluster database with version 5.0.3-v1.

Deploy Redis cluster :

In this section, we are going to deploy a Redis cluster database. Then, in the next section we will update the version of the database using RedisOpsRequest CRD. Below is the YAML of the Redis CR that we are going to create,

apiVersion: kubedb.com/v1alpha2
kind: Redis
metadata:
  name: redis-cluster
  namespace: demo
spec:
  version: 6.0.6
  mode: Cluster
  cluster:
    master: 3
    replicas: 1
  storageType: Durable
  storage:
    resources:
      requests:
        storage: "100Mi"
    storageClassName: "standard"
    accessModes:
      - ReadWriteOnce
  terminationPolicy: Halt

Let’s create the Redis CR we have shown above,

$ kubectl create -f https://github.com/kubedb/docs/raw/v2023.02.28/docs/examples/redis/upgrading/rd-cluster.yaml
redis.kubedb.com/redis-cluster created

Now, wait until redis-cluster created has status Ready. i.e,

$ kubectl get rd -n demo
NAME            VERSION   STATUS   AGE
redis-cluster   6.0.6     Ready    88s

We are now ready to apply the RedisOpsRequest CR to upgrade this database.

Update Redis Version

Here, we are going to update Redis cluster from 6.0.6 to 7.0.5.

Create RedisOpsRequest:

In order to update the cluster database, we have to create a RedisOpsRequest CR with your desired version that is supported by KubeDB. Below is the YAML of the RedisOpsRequest CR that we are going to create,

apiVersion: ops.kubedb.com/v1alpha1
kind: RedisOpsRequest
metadata:
  name: update-version
  namespace: demo
spec:
  type: UpdateVersion
  databaseRef:
    name: redis-cluster
  upgrade:
    targetVersion: 7.0.5

Here,

• spec.databaseRef.name specifies that we are performing operation on redis-cluster Redis database.
• spec.type specifies that we are going to perform UpdateVersion on our database.
• spec.upgrade.targetVersion specifies the expected version of the database 7.0.5.

Let’s create the RedisOpsRequest CR we have shown above,

$ kubectl apply -f https://github.com/kubedb/docs/raw/v2023.02.28/docs/examples/redis/upgrading/update-version.yaml
redisopsrequest.ops.kubedb.com/update-version created

Verify Redis version upgraded successfully :

If everything goes well, KubeDB Enterprise operator will update the image of Redis object and related StatefulSets and Pods.

Let’s wait for RedisOpsRequest to be Successful. Run the following command to watch RedisOpsRequest CR,

$ watch kubectl get redisopsrequest -n demo
Every 2.0s: kubectl get redisopsrequest -n demo
NAME              TYPE            STATUS       AGE
update-version    UpdateVersion   Successful   4m6s

We can see from the above output that the RedisOpsRequest has succeeded.

Now, we are going to verify whether the Redis and the related StatefulSets their Pods have the new version image. Let’s check,

$ kubectl get redis -n demo redis-cluster -o=jsonpath='{.spec.version}{"\n"}'
7.0.5

$ kubectl get statefulset -n demo redis-cluster-shard0 -o=jsonpath='{.spec.template.spec.containers[0].image}{"\n"}'
redis:7.0.5@sha256:dfeb5451fce377ab47c5bb6b6826592eea534279354bbfc3890c0b5e9b57c763

$ kubectl get pods -n demo redis-cluster-shard1-1 -o=jsonpath='{.spec.containers[0].image}{"\n"}'
redis:7.0.5@sha256:dfeb5451fce377ab47c5bb6b6826592eea534279354bbfc3890c0b5e9b57c763

You can see from above, our Redis cluster database has been updated with the new version. So, the update process is successfully completed.

Cleaning Up

To clean up the Kubernetes resources created by this tutorial, run:

$ kubectl patch -n demo rd/redis-cluster -p '{"spec":{"terminationPolicy":"WipeOut"}}' --type="merge"
redis.kubedb.com/redis-quickstart patched

$ kubectl delete -n demo redis redis-cluster
redis.kubedb.com "redis-cluster" deleted

$ kubectl delete -n demo redisopsrequest update-version
redisopsrequest.ops.kubedb.com "update-version" deleted