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Update version of Redis Sentinel

This guide will show you how to use KubeDB Enterprise operator to update the version of Redis in Sentinel mode and RedisSentinel.

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
  • RedisSentinel
  • RedisOpsRequest
  • updating 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 Sentinel Database

Now, we are going to deploy a RedisSentinel instance with version 6.2.7 and a Redis database with version 6.2.5. Then, in the next section we will update the version of the sentinel and the database using RedisOpsRequest CRD

Deploy RedisSentinel :

In this section, we are going to deploy a RedisSentinel instance. Below is the YAML of the RedisSentinel CR that we are going to create,

apiVersion: kubedb.com/v1alpha2
kind: RedisSentinel
metadata:
  name: sen-sample
  namespace: demo
spec:
  version: 6.2.7
  replicas: 3
  storageType: Durable
  storage:
    resources:
      requests:
        storage: 1Gi
    storageClassName: "standard"
    accessModes:
      - ReadWriteOnce
  terminationPolicy: DoNotTerminate

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

$ kubectl create -f https://github.com/kubedb/docs/raw/v2023.04.10/docs/examples/redis/update-version/sentinel.yaml
redissentinel.kubedb.com/sen-sample created

Now, wait until sen-sample created has status Ready. i.e,

$ kubectl get redissentinel -n demo
NAME         VERSION   STATUS   AGE
sen-sample   6.2.7     Ready    5m20s

Deploy Redis :

In this section, we are going to deploy a Redis instance which will be monitored by previously created sen-sample. Below is the YAML of the Redis CR that we are going to create,

apiVersion: kubedb.com/v1alpha2
kind: Redis
metadata:
  name: rd-sample
  namespace: demo
spec:
  version: 6.2.5
  replicas: 3
  sentinelRef:
    name: sen-sample
    namespace: demo
  mode: Sentinel
  storageType: Durable
  storage:
    resources:
      requests:
        storage: 1Gi
    storageClassName: "standard"
    accessModes:
      - ReadWriteOnce
  terminationPolicy: DoNotTerminate

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

$ kubectl create -f https://github.com/kubedb/docs/raw/v2023.04.10/docs/examples/redis/update-version/rd-sentinel.yaml
redis.kubedb.com/rd-sample created

Now, wait until rd-sample created has status Ready. i.e,

$ kubectl get redis -n demo
NAME        VERSION   STATUS   AGE
rd-sample   6.2.5     Ready    2m11s

We are now ready to apply the RedisSentinelOpsRequest CR to update the sentinel version and RedisOpsRequest CR to update the database version.

Update RedisSentinel Version

Here, we are going to update RedisSentinel standalone from 6.2.7 to 7.0.5.

Create RedisSentinelOpsRequest:

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

apiVersion: ops.kubedb.com/v1alpha1
kind: RedisSentinelOpsRequest
metadata:
  name: update-sen-version
  namespace: demo
spec:
  type: UpdateVersion
  databaseRef:
    name: sen-sample
  updateVersion:
    targetVersion: 7.0.5

Here,

• spec.databaseRef.name specifies that we are performing operation on sen-sample RedisSentinel instance.
• spec.type specifies that we are going to perform UpdateVersion on our database.
• spec.updateVersion.targetVersion specifies the expected version of the database 7.0.5.

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

$ kubectl apply -f https://github.com/kubedb/docs/raw/v2023.04.10/docs/examples/redis/update-version/update-sentinel.yaml
redissentinelopsrequest.ops.kubedb.com/update-sen-version created

Verify RedisSentinel version updated successfully :

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

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

$ watch kubectl get redissentinelopsrequest -n demo
Every 2.0s: kubectl get redissentinelopsrequest -n demo
NAME                  TYPE            STATUS       AGE
update-sen-version    UpdateVersion   Successful   3m30s

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

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

$ kubectl get redissentinel -n demo sen-sample -o=jsonpath='{.spec.version}{"\n"}'
7.0.5

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

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

You can see from above, our RedisSentinel sen-demo has been updated with the new version. So, the UpdateVersion process is successfully completed.

Update Redis Version

Here, we are going to update Redis standalone from 6.2.5 to 7.0.4.

Create RedispsRequest:

In order to update the redis 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-rd-version
  namespace: demo
spec:
  type: UpdateVersion
  databaseRef:
    name: rd-sample
  updateVersion:
    targetVersion: 7.0.4

Here,

• spec.databaseRef.name specifies that we are performing operation on rd-sample Redis database.
• spec.type specifies that we are going to perform UpdateVersion on our database.
• spec.updateVersion.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/v2023.04.10/docs/examples/redis/update-version/update-redis-sentinel.yaml
redisopsrequest.ops.kubedb.com/update-rd-version created

Verify Redis version updated 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-rd-version    UpdateVersion   Successful   5m40s

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 rd-sample -o=jsonpath='{.spec.version}{"\n"}'
7.0.4

$ kubectl get statefulset -n demo rd-sample -o=jsonpath='{.spec.template.spec.containers[1].image}{"\n"}'
redis:7.0.4@sha256:091a7b5de688f283b30a4942280b64cf822bbdab0abfb2d2ce6db989f2d3c3f4

$ kubectl get pods -n demo rd-sample-0 -o=jsonpath='{.spec.containers[1].image}{"\n"}'
redis:7.0.4@sha256:091a7b5de688f283b30a4942280b64cf822bbdab0abfb2d2ce6db989f2d3c3f4

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

Cleaning Up

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

# Delete Redis and RedisOpsRequest
$ kubectl patch -n demo rd/rd-sample -p '{"spec":{"terminationPolicy":"WipeOut"}}' --type="merge"
redis.kubedb.com/rd-sample patched

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

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

# Delete RedisSentinel and RedisSentinelOpsRequest
$ kubectl patch -n demo redissentinel/sen-sample -p '{"spec":{"terminationPolicy":"WipeOut"}}' --type="merge"
redissentinel.kubedb.com/sen-sample patched

$ kubectl delete -n demo redissentinel sen-sample
redissentinel.kubedb.com "sen-sample" deleted

$ kubectl delete -n demo redissentinelopsrequests update-sen-version
redissentinelopsrequest.ops.kubedb.com "update-sen-version" deleted