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Cross-Cluster Backup and Restore
This guide will show you how to take backup and restore across clusters using Stash.
Before You Begin
At first, you need to have running Kubernetes clusters, and the
kubectl
command-line tool must be configured to communicate with your clusters. We will use kind clusters throughout this tutorial. To know more about kind clusters, follow this doc here.You should be familiar with the following
Stash
concepts:
Backup from prod
Cluster
To demonstrate the cross-clusters backup and restore capabilities, we will use the prod
cluster for taking backup and restoring the backup into the staging
cluster.
Prepare Cluster
Let’s create a cluster named prod
,
$ kind create cluster --name prod
Creating cluster "prod" ...
â Ensuring node image (kindest/node:v1.23.0) đŧ
â Preparing nodes đĻ
â Writing configuration đ
â Starting control-plane đšī¸
â Installing CNI đ
â Installing StorageClass đž
Set kubectl context to "kind-prod"
You can now use your cluster with:
kubectl cluster-info --context kind-prod
Have a nice day! đ
To verify your current cluster,
$ kubectl config current-context
kind-prod
if you are currently not in the prod
cluster, you can switch your cluster by the following command,
$ kubectl config use-context kind-prod
Switched to context "kind-prod".
We are going to create a namespace named demo
in the prod
cluster,
$ kubectl create ns demo
namespace/demo created
Note: YAML files used in this tutorial can be found here.
Install Stash
in your prod
cluster following the steps here.
Deploy Workload
Let’s deploy a Deployment and an associated PVC in the prod
cluster at the beginning. This Deployment will automatically generate sample data in the /source/data
directory.
Below are the YAMLs of the Deployment and PVC that we are going to create,
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: stash-sample-data
namespace: demo
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
---
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: stash-demo
name: stash-demo
namespace: demo
spec:
replicas: 3
selector:
matchLabels:
app: stash-demo
template:
metadata:
labels:
app: stash-demo
name: busybox
spec:
containers:
- args: ["echo sample_data > /source/data/data.txt && sleep 3000"]
command: ["/bin/sh", "-c"]
image: busybox
imagePullPolicy: IfNotPresent
name: busybox
volumeMounts:
- mountPath: /source/data
name: source-data
restartPolicy: Always
volumes:
- name: source-data
persistentVolumeClaim:
claimName: stash-sample-data
Let’s create the Deployment and PVC we have shown above,
$ kubectl apply -f https://github.com/stashed/docs/raw/v2022.12.11/docs/guides/use-cases/cross-cluster-backup/examples/deployment_prod.yaml
persistentvolumeclaim/stash-sample-data created
deployment.apps/stash-demo created
Now, wait for the pods of the Deployment to go into the Running
state. You can verify the Status
of the pods by executing the following command,
$ kubectl get pods -n demo
NAME READY STATUS RESTARTS AGE
stash-demo-7678679bcb-2s927 1/1 Running 0 29s
stash-demo-7678679bcb-b849l 1/1 Running 0 29s
stash-demo-7678679bcb-p62vn 1/1 Running 0 29s
Verify that the sample data has been created in /source/data
directory using the following command,
$ kubectl exec -n demo stash-demo-7678679bcb-2s927 -- cat /source/data/data.txt
sample_data
Prepare Backend
We are going to store our backed-up data into a GCS bucket. We have to create a Secret with the necessary credentials and a Repository CRD to use this backend.
If you want to use a different backend, please read the respective backend configuration doc here.
For GCS backend, if the bucket does not exist, Stash needs
Storage Object Admin
role permissions to create the bucket. For more details, please check the following guide.
Create Secret:
Let’s create a secret called gcs-secret
in demo
namespace with access credentials to our desired GCS bucket,
$ echo -n 'changeit' > RESTIC_PASSWORD
$ echo -n '<your-project-id>' > GOOGLE_PROJECT_ID
$ cat /path/to/downloaded-sa-key.json > GOOGLE_SERVICE_ACCOUNT_JSON_KEY
$ kubectl create secret generic -n demo gcs-secret \
--from-file=./RESTIC_PASSWORD \
--from-file=./GOOGLE_PROJECT_ID \
--from-file=./GOOGLE_SERVICE_ACCOUNT_JSON_KEY
secret/gcs-secret created
Now, we are ready to backup our workload’s data to our desired backend.
Create Repository:
Now, create a Repository
using this secret. Below is the YAML of the Repository
object we are going to create,
apiVersion: stash.appscode.com/v1alpha1
kind: Repository
metadata:
name: gcs-repo
namespace: demo
spec:
backend:
gcs:
bucket: stash-testing
prefix: /cross-cluster/deployment/sample-deployment
storageSecretName: gcs-secret
Let’s create the Repository we have shown above,
$ kubectl apply -f https://github.com/stashed/docs/raw/v2022.12.11/docs/guides/use-cases/cross-cluster-backup/examples/repository_prod.yaml
repository.stash.appscode.com/gcs-repo created
Now, we are ready to backup our sample data into this backend.
Configure Backup
We are going to create a BackupConfiguration
object in the demo
namespace targeting the stash-demo
Deployment that we have deployed earlier. This BackupConfiguration
will refer to the gcs-repo
repository. Stash will inject a sidecar container into the target. It will also create a CronJob
to take periodic backup of the /source/data
directory of the target.
Create BackupConfiguration:
Below is the YAML of the BackupConfiguration
crd that we are going to create,
apiVersion: stash.appscode.com/v1beta1
kind: BackupConfiguration
metadata:
name: deployment-backup
namespace: demo
spec:
repository:
name: gcs-repo
schedule: "*/5 * * * *"
target:
ref:
apiVersion: apps/v1
kind: Deployment
name: stash-demo
volumeMounts:
- name: source-data
mountPath: /source/data
paths:
- /source/data
retentionPolicy:
name: 'keep-last-5'
keepLast: 5
prune: true
Here,
spec.repository.name
refers to the Repository object that holds backend information.spec.schedule
is a cron expression that indicates BackupSession will be created at 5 minutes intervals.spec.target.ref
refers to thestash-demo
Deployment.spec.target.volumeMounts
specifies a list of volumes and their mountPath that contain the target paths.spec.target.paths
specifies list of file paths to backup.
Let’s create the BackupConfiguration
object we have shown above,
$ kubectl apply -f https://github.com/stashed/docs/raw/v2022.12.11/docs/guides/use-cases/cross-cluster-backup/examples/backupconfiguration_prod.yaml
backupconfiguration.stash.appscode.com/deployment-backup created
Verify BackupConfiguration Ready:
If everything goes well, the Phase of the BackupConfiguration should be Ready
. Let’s check the BackupConfiguration phase,
⯠kubectl get backupconfiguration -n demo
NAME TASK SCHEDULE PAUSED PHASE AGE
deployment-backup */5 * * * * Ready 48s
Verify CronJob:
Stash will also create a CronJob
with the schedule specified in the spec.schedule
field of the BackupConfiguration
crd.
Verify that the CronJob
has been created using the following command,
$ kubectl get cronjob -n prod
NAME SCHEDULE SUSPEND ACTIVE LAST SCHEDULE AGE
stash-trigger-deployment-backup */5 * * * * False 0 28s 2m14s
Verify Backup
The stash-trigger-deployment-backup
CronJob will trigger a backup on each scheduled slot by creating a BackupSession
crd. The sidecar container watches for the BackupSession
object. When it finds one, it will take backup immediately.
Wait for the next schedule for the backup. Run the following command to watch BackupSession
crd,
$ kubectl get backupsession -n prod -w
NAME INVOKER-TYPE INVOKER-NAME PHASE DURATION AGE
deployment-backup-1647238200 BackupConfiguration deployment-backup Running 5s
deployment-backup-1647238200 BackupConfiguration deployment-backup Running 16s
deployment-backup-1647238200 BackupConfiguration deployment-backup Running 27s
deployment-backup-1647238200 BackupConfiguration deployment-backup Succeeded 28s 27s
We can see from the above output that the backup session has succeeded.
Restore into staging
Cluster
This section will demonstrate restoring the backed-up data into the staging
cluster.
Stop Taking Backup of the Old Deployment:
At first, let’s stop taking any further backup of the old Deployment so that no backup is taken during the restore process. We are going to pause the BackupConfiguration
that we created earlier. Then, Stash will stop taking any further backup for this Deployment. You can learn more how to pause a scheduled backup here
Let’s pause the deployment-backup
BackupConfiguration,
$ kubectl patch backupconfiguration -n demo deployment-backup --type="merge" --patch='{"spec": {"paused": true}}'
backupconfiguration.stash.appscode.com/deployment-backup patched
You can also use the Stash kubectl plugin to pause the backup like the following,
$ kubectl stash pause backup --backupconfig=deployment-backup -n demo
BackupConfiguration demo/deployment-backup has been paused successfully.
Verify that the BackupConfiguration has been paused,
$ kubectl get backupconfiguration -n demo
NAME TASK SCHEDULE PAUSED PHASE AGE
deployment-backup */5 * * * * true Ready 49m
Notice the PAUSED
column. Value true
indicates that the BackupConfiguration has been paused.
Prepare Cluster
Let’s create a cluster named staging
,
$ kind create cluster --name staging
Creating cluster "staging" ...
â Ensuring node image (kindest/node:v1.23.0) đŧ
â Preparing nodes đĻ
â Writing configuration đ
â Starting control-plane đšī¸
â Installing CNI đ
â Installing StorageClass đž
Set kubectl context to "kind-staging"
You can now use your cluster with:
kubectl cluster-info --context kind-staging
Have a nice day! đ
To verify the current cluster you are working on,
$ kubectl config current-context
kind-staging
If you are currently not in the staging
cluster, you can switch your cluster by the following command,
$ kubectl config use-context kind-staging
Switched to context "kind-staging".
We are going to create a namespace named demo
in the staging
cluster,
$ kubectl create ns demo
namespace/demo created
Install Stash
in your staging
cluster following the steps here.
Deploy Restore Workload
We are going to create a new Deployment named stash-recovered
and a PVC as a storage of the Deployment. We will restore the backed-up data inside it.
Here is the YAML of the PVC and the Deployment,
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: demo-pvc
namespace: demo
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
---
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: stash-recovered
name: stash-recovered
namespace: demo
spec:
replicas: 3
selector:
matchLabels:
app: stash-recovered
template:
metadata:
labels:
app: stash-recovered
name: busybox
spec:
containers:
- args:
- sleep
- "3600"
image: busybox
imagePullPolicy: IfNotPresent
name: busybox
volumeMounts:
- mountPath: /source/data
name: source-data
restartPolicy: Always
volumes:
- name: source-data
persistentVolumeClaim:
claimName: demo-pvc
Let’s create the Deployment we have shown above.
$ kubectl apply -f https://github.com/stashed/docs/raw/v2022.12.11/docs/guides/use-cases/cross-cluster-backup/examples/deployment_staging.yaml
persistentvolumeclaim/demo-pvc created
deployment.apps/stash-recovered created
Prepare Backend Info
We have to re-create the Repository CR and the respective Secret that we have used in the prod
cluster.
Create Secret:
Let’s create a secret called gcs-secret
in demo
namespace with access credentials to our GCS bucket,
$ echo -n 'changeit' > RESTIC_PASSWORD
$ echo -n '<your-project-id>' > GOOGLE_PROJECT_ID
$ cat /path/to/downloaded-sa-key.json > GOOGLE_SERVICE_ACCOUNT_JSON_KEY
$ kubectl create secret generic -n demo gcs-secret \
--from-file=./RESTIC_PASSWORD \
--from-file=./GOOGLE_PROJECT_ID \
--from-file=./GOOGLE_SERVICE_ACCOUNT_JSON_KEY
secret/gcs-secret created
Create Repository:
Now, create a Repository
using this secret. Below is the YAML of Repository
crd we are going to create,
apiVersion: stash.appscode.com/v1alpha1
kind: Repository
metadata:
name: gcs-repo
namespace: demo
spec:
backend:
gcs:
bucket: stash-testing
prefix: /cross-cluster/deployment/sample-deployment
storageSecretName: gcs-secret
Let’s create the Repository we have shown above,
$ kubectl apply -f https://github.com/stashed/docs/raw/v2022.12.11/docs/guides/use-cases/cross-cluster-backup/examples/repository_prod.yaml
repository.stash.appscode.com/gcs-repo created
Now, we are ready to restore our sample data from this specified backend.
Configure Restore
Now, we need to create a RestoreSession
object targeting the stash-recovered
Deployment to restore the backed-up data inside it.
Create RestoreSession:
Below is the YAML of the RestoreSesion
object that we are going to create,
apiVersion: stash.appscode.com/v1beta1
kind: RestoreSession
metadata:
name: deployment-restore
namespace: demo
spec:
repository:
name: gcs-repo
target: # target indicates where the recovered data will be stored
ref:
apiVersion: apps/v1
kind: Deployment
name: stash-recovered
volumeMounts:
- name: source-data
mountPath: /source/data
rules:
- paths:
- /source/data/
Here,
spec.repository.name
specifies the name of the Repository.spec.target.ref
refers to the target workload where the recovered data will be stored.spec.target.volumeMounts
specifies a list of volumes and their mountPath where the data will be restored.mountPath
must be the same mountPath as the original volume because Stash stores the absolute path of the backed-up files. If you use a different mountPath for the restored volume the backed up files will not be restored into your desired volume.
Let’s create the RestoreSession
crd we have shown above,
$ kubectl apply -f https://github.com/stashed/docs/raw/v2022.12.11/docs/guides/use-cases/cross-cluster-backup/examples/restoresession_staging.yaml
restoresession.stash.appscode.com/deployment-restore created
Now, wait for the RestoreSession phase to go into Succeeded
state.
Wait for RestoreSession to Succeeded:
Run the following command to watch the RestoreSession phase,
$ kubectl get restoresession -n demo -w
NAME REPOSITORY PHASE DURATION AGE
deployment-restore gcs-repo Succeeded 10s 35s
So, we can see from the output of the above command that the restore process succeeded.
Verify Restored Data
In this section, we are going to verify whether the desired data has been restored successfully or not.
Get the pods of the stash-recovered
Deployment,
$ kubectl get pods -n demo -l app='stash-recovered'
NAME READY STATUS RESTARTS AGE
stash-recovered-56547b7b57-scxl4 1/1 Running 0 16m
stash-recovered-56547b7b57-w4rf5 1/1 Running 0 16m
stash-recovered-56547b7b57-zxb2p 1/1 Running 0 16m
Verify that the backed-up data has been restored in /source/data
directory of the stash-recovered
pods of the Deployment using the following commands,
$ kubectl exec -n demo stash-recovered-56547b7b57-scxl4 -- cat /source/data/data.txt
sample_data
Cleaning Up
To clean up the Kubernetes resources created by this tutorial in prod
and staging
clusters, run the following commands:
Cleanup prod
Cluster
Switch your cluster to prod
,
$ kubectl config use-context kind-prod
Switched to context "kind-prod".
Clean up the Stash resources in the prod
cluster,
kubectl delete -n demo deployments stash-demo
kubectl delete -n demo pvc stash-sample-data
kubectl delete -n demo backupconfiguration deployment-backup
kubectl delete -n demo repository gcs-repo
kubectl delete -n demo secret gcs-secret
Cleanup staging
Cluster
Switch your cluster to staging
,
$ kubectl config use-context kind-staging
Switched to context "kind-staging".
Clean up the Stash resources in the staging
cluster,
kubectl delete -n demo deployments stash-recovered
kubectl delete -n demo pvc demo-pvc
kubectl delete -n demo restoresession deployment-restore
kubectl delete -n demo repository gcs-repo
kubectl delete -n demo secret gcs-secret