Redis is the open source, in-memory data store used by millions of developers as a database, cache, streaming engine and message broker.
We will be using Redis chart that bootstraps a Redis deployment on a Kubernetes cluster using the Helm package manager.
- Kubernetes 1.20+
- PV provisioner support in the underlying infrastructure
- Kanister controller version 0.112.0 installed in your cluster, let's assume in Namespace
kanister - Kanctl CLI installed (https://docs.kanister.io/tooling.html#install-the-tools)
- Docker CLI installed
- A docker image containing the required tools to back up Redis. The Dockerfile for the image can be found here. To build and push the docker image to your docker registry, execute these steps.
- Execute below commands to build and push
redis-toolsdocker image to a registry.
# On your local kanister git repo
$ cd ~/kanister/docker/redis-tools
$ docker build -t <registry>/<account_name>/redis-tools:<tag_name> .
$ docker push <registry>/<account_name>/redis-tools:<tag_name>Execute the below commands to install the Redis database using the bitnami chart with the release name redis:
# Add bitnami in your local chart repository
$ helm repo add bitnami https://charts.bitnami.com/bitnami
# Update your local chart repository
$ helm repo update
# Install the Redis database
$ helm install redis bitnami/redis --namespace redis-test --create-namespace \
--set auth.password='<redis-password>' --set volumePermissions.enabled=trueThe command deploys a Redis instance in the redis-test namespace.
By default a random password will be generated for the user. For setting your own password, use the auth.password param as shown above.
You can retrieve your root password by running the following command. Make sure to replace [YOUR_RELEASE_NAME] and [YOUR_NAMESPACE]:
`kubectl get secret [YOUR_RELEASE_NAME] --namespace [YOUR_NAMESPACE] -o jsonpath="{.data.redis-password}" | base64 -d`
Tip: List all releases using
helm list --all-namespaces, using Helm Version 3.
If you have deployed Redis application with name other than redis and namespace other than redis-test, you need to modify the commands (backup, restore and delete) used below to use the correct release name and namespace.
Create Profile CR if not created already
$ kanctl create profile s3compliant --access-key <aws-access-key-id> \
--secret-key <aws-secret-key> \
--bucket <s3-bucket-name> --region <region-name> \
--namespace redis-testYou can read more about the Profile custom Kanister resource here.
NOTE:
The above command will configure a location where artifacts resulting from Kanister
data operations such as backup should go. This is stored as a profiles.cr.kanister.io
CustomResource (CR) which is then referenced in Kanister ActionSets. Every ActionSet
requires a Profile reference to complete the action. This CR (profiles.cr.kanister.io)
can be shared between Kanister-enabled application instances.
Create Blueprint in the same namespace as the Kanister controller
NOTE:
Replace <registry>, <account_name> and <tag_name> for the image value in ./redis-blueprint.yaml before running following command.
$ kubectl create -f ./redis-blueprint.yaml -n kanisterOnce Redis is running, you can populate it with some data. Let's add a key called "name":
# Connect to Redis by running a shell inside Redis' pod
$ kubectl -n redis-test exec -it redis-master-0 -- bash
# From inside the shell, use the redis-cli to insert some data
# Replace redis-password with the password that you have set while installing Redis
$ redis-cli -a <redis-password>
# Set value for "name" key
127.0.0.1:6379> set name test-redis
OK
# Verify value is properly set
127.0.0.1:6379> get name
"test-redis"You can now take a backup of the Redis data using an ActionSet defining backup for this application. Create an ActionSet in the same namespace as the controller.
# Find profile name
$ kubectl get profile -n redis-test
NAME AGE
s3-profile-75ql6 2m
# Create Actionset
# Make sure the value of profile and blueprint matches the names of profile and blueprint created above
$ kanctl create actionset --action backup --namespace kanister --blueprint redis-blueprint --statefulset redis-test/redis-master --profile redis-test/s3-profile-75ql6 --secrets redis=redis-test/redis
actionset backup-ms8wg created
# View the status of the actionset
$ kubectl --namespace kanister get actionsets.cr.kanister.io backup-ms8wg
NAME PROGRESS LAST TRANSITION TIME STATE
backup-ms8wg 100.00 2022-12-30T08:26:36Z completeLet's say someone accidentally deleted the key using the following command:
# Connect to Redis by running a shell inside Redis' pod
$ kubectl -n redis-test exec -it redis-master-0 -- bash
# From inside the shell, use the redis-cli to insert some data
# Replace redis-password with the password that you have set while installing Redis
$ redis-cli -a <redis-password>
# Delete key from Redis
127.0.0.1:6379> get name
"test-redis"
127.0.0.1:6379> del name
(integer) 1
127.0.0.1:6379> get name
(nil)To restore the missing data, you should use the backup that you created before. An easy way to do this is to leverage kanctl, a command-line tool that helps create ActionSets that depend on other ActionSets:
# Make sure to use correct backup actionset name here
$ kanctl --namespace kanister create actionset --action restore --from backup-ms8wg
actionset restore-backup-ms8wg-2c4c7 created
# View the status of the ActionSet
$ kubectl --namespace kanister get actionsets.cr.kanister.io restore-backup-ms8wg-2c4c7
NAME PROGRESS LAST TRANSITION TIME STATE
restore-backup-ms8wg-2c4c7 100.00 2022-12-30T08:42:21Z completeOnce the ActionSet status is set to "complete", you can verify that the data has been successfully restored to Redis.
# Connect to Redis by running a shell inside Redis' pod
$ kubectl -n redis-test exec -it redis-master-0 -- bash
# From inside the shell, use the redis-cli to insert some data
# Replace redis-password with the password that you have set while installing Redis
$ redis-cli -a <redis-password>
127.0.0.1:6379> get name
"test-redis"The artifacts created by the backup action can be cleaned up using the following command:
$ kanctl --namespace kanister create actionset --action delete --from backup-ms8wg --namespacetargets kanister
actionset delete-backup-ms8wg-b6lz4 created
# View the status of the ActionSet
$ kubectl --namespace kanister get actionsets.cr.kanister.io delete-backup-ms8wg-b6lz4
NAME PROGRESS LAST TRANSITION TIME STATE
delete-backup-ms8wg-b6lz4 100.00 2022-12-30T08:44:40Z completeIf you run into any issues with the above commands, you can check the logs of the controller using:
$ kubectl --namespace kanister logs -l app=kanister-operatoryou can also check events of the actionset
$ kubectl describe actionset restore-backup-ms8wg-2c4c7 -n kanisterTo uninstall/delete the redis deployment:
# Helm Version 3
$ helm delete redis -n redis-test
release "redis" uninstalledThe command removes all the Kubernetes components associated with the chart and deletes the release.
Remove Blueprint, Profile CR and ActionSets
$ kubectl delete blueprints.cr.kanister.io redis-blueprint -n kanister
blueprint.cr.kanister.io "redis-blueprint" deleted
$ kubectl get profiles.cr.kanister.io -n redis-test
NAME AGE
s3-profile-75ql6 23m
$ kubectl delete profiles.cr.kanister.io s3-profile-75ql6 -n redis-test
profile.cr.kanister.io "s3-profile-75ql6" deleted
$ kubectl --namespace kanister delete actionsets.cr.kanister.io backup-ms8wg delete-backup-ms8wg-b6lz4 restore-backup-ms8wg-2c4c7
actionset.cr.kanister.io "backup-ms8wg" deleted
actionset.cr.kanister.io "delete-backup-ms8wg-b6lz4" deleted
actionset.cr.kanister.io "restore-backup-ms8wg-2c4c7" deleted