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This tutorial will show you how to use Stash to backup and restore a Kubernetes volume in Rook storage service. Here, we are going to backup the
/source/data folder of a busybox pod into AWS S3 compatible Rook Object Storage. Then, we are going to show how to recover this data into a
PersistentVolumeClaim of Rook Block Storage. We are going to also re-deploy deployment using this recovered volume.
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.
Stash in your cluster following the steps here.
You should be familiar with the following Stash concepts:
You will need a Rook Storage Service with Object Storage and Block Storage configured. If you do not already have a Rook Storage Service configured, you can create one by following this quickstart guide.
To keep things isolated, we are going to use a separate namespace called
demo throughout this tutorial.
$ kubectl create ns demo namespace/demo created
In order to take backup, we need some sample data. Stash has some sample data in stash-data repository. As gitRepo volume has been deprecated, we are not going to use this repository as volume directly. Instead, we are going to create a configMap from the stash-data repository and use that ConfigMap as data source.
Let’s create a ConfigMap from these sample data,
$ kubectl create configmap -n demo stash-sample-data \ --from-literal=LICENSE="$(curl -fsSL https://github.com/stashed/stash-data/raw/master/LICENSE)" \ --from-literal=README.md="$(curl -fsSL https://github.com/stashed/stash-data/raw/master/README.md)" configmap/stash-sample-data created
Now, deploy the following Deployment. Here, we have mounted the ConfigMap
stash-sample-data as data source volume.
Below, the YAML for the Deployment we are going to create.
apiVersion: apps/v1 kind: Deployment metadata: labels: app: stash-demo name: stash-demo namespace: demo spec: replicas: 1 selector: matchLabels: app: stash-demo template: metadata: labels: app: stash-demo 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 configMap: name: stash-sample-data
Let’s create the deployment we have shown above,
$ kubectl apply -f https://github.com/stashed/docs/raw/v2021.03.17/docs/examples/platforms/rook/deployment.yaml deployment.apps/stash-demo created
Now, wait for deployment’s pod to go in
$ kubectl get pod -n demo -l app=stash-demo NAME READY STATUS RESTARTS AGE stash-demo-7ccd56bf5d-fm74f 1/1 Running 0 18s
You can check that the
/source/data/ directory of this pod is populated with data from the
stash-sample-data ConfigMap using this command,
$ kubectl exec -n demo stash-demo-7ccd56bf5d-fm74f -- ls -R /source/data /source/data: LICENSE README.md
Now, we are ready to backup
/source/data directory into a Rook bucket.
At first, we need to create a secret for
Restic crd. To configure this backend, the following secret keys are needed:
Create the secret as below,
$ echo -n 'changeit' > RESTIC_PASSWORD $ echo -n '<your-rook-access-key-here>' > AWS_ACCESS_KEY_ID $ echo -n '<your-rook-secret-key-here>' > AWS_SECRET_ACCESS_KEY $ kubectl create secret generic -n demo rook-secret \ --from-file=./RESTIC_PASSWORD \ --from-file=./AWS_ACCESS_KEY_ID \ --from-file=./AWS_SECRET_ACCESS_KEY secret/rook-secret created
Verify that the secret has been created successfully,
$ kubectl get secret -n demo rook-secret -o yaml
apiVersion: v1 data: AWS_ACCESS_KEY_ID: UlhSQ0oyVjRZNlpFQUlBV0UyTEc= AWS_SECRET_ACCESS_KEY: YWVtZG9IZ1g3UXBUSzF0VXpPZHVJcUNPb01sc1cwZlZES0RRaXM2MA== RESTIC_PASSWORD: Y2hhbmdlaXQ= kind: Secret metadata: creationTimestamp: 2018-12-06T07:24:58Z name: rook-secret namespace: demo resourceVersion: "4680" selfLink: /api/v1/namespaces/demo/secrets/rook-secret uid: 0958c36c-f928-11e8-998e-080027a2d1ee type: Opaque
Now, we are going to create
Restic crd to take backup
/source/data directory of
stash-demo deployment. This will create a repository in the Rook bucket specified by
s3.bucket field and start taking periodic backup of
$ kubectl apply -f https://github.com/stashed/docs/raw/v2021.03.17/docs/examples/platforms/rook/restic.yaml restic.stash.appscode.com/rook-restic created
Below, the YAML for Restic crd we have created above,
apiVersion: stash.appscode.com/v1alpha1 kind: Restic metadata: name: rook-restic namespace: demo spec: selector: matchLabels: app: stash-demo # Must match with the label of pod we want to backup. fileGroups: - path: /source/data retentionPolicyName: 'keep-last-5' backend: s3: endpoint: 'http://rook-ceph-rgw-my-store.rook-ceph.svc' # Use your own rook object storage endpoint. bucket: stash-backup # Give a name of the bucket where you want to backup. prefix: demo # A prefix for the directory where repository will be created.(optional). storageSecretName: rook-secret schedule: '@every 1m' volumeMounts: - mountPath: /source/data name: source-data retentionPolicies: - name: 'keep-last-5' keepLast: 5 prune: true
If everything goes well,
Stash will inject a sidecar container into the
stash-demo deployment to take periodic backup. Let’s check that sidecar has been injected successfully,
$ kubectl get pod -n demo -l app=stash-demo NAME READY STATUS RESTARTS AGE stash-demo-6c9cd4cf4c-bn5wm 2/2 Running 0 53s
Look at the pod. It now has 2 containers. If you view the resource definition of this pod, you will see that there is a container named
stash which running
Stash will create a
Repository crd with name
deployment.stash-demo for the respective repository in Rook backend at first backup schedule. To verify, run the following command,
$ kubectl get repository deployment.stash-demo -n demo NAME BACKUPCOUNT LASTSUCCESSFULBACKUP AGE deployment.stash-demo 1 41s 1m
BACKUPCOUNT field indicates number of backup snapshot has taken in this repository.
Restic will take backup of the volume periodically with a 1-minute interval. You can verify that backup snapshots has been created successfully by,
$ kubectl get snapshots -n demo -l repository=deployment.stash-demo NAME AGE NAME AGE deployment.stash-demo-2960b90e 4m3s deployment.stash-demo-79626d95 3m3s deployment.stash-demo-6c5eb448 2m3s deployment.stash-demo-05761ab3 63s deployment.stash-demo-f8937bdf 2s
Here, we can see 5 last successful backup Snapshot taken by Stash in
Now, consider that we have lost our workload as well as data volume. We want to recover the data into a new volume and re-deploy the workload.
At first, let’s delete
stash-demo deployment and
$ kubectl delete deployment -n demo stash-demo deployment.extensions "stash-demo" deleted $ kubectl delete restic -n demo rook-restic restic.stash.appscode.com "rook-restic" deleted $ kubectl delete configmap -n demo stash-sample-data configmap "stash-sample-data" deleted
In order to perform recovery, we need
deployment.stah-demo and backend secret
rook-secret to exist.
In case of cluster disaster, you might lose
Repositorycrd and backend secret. In this scenario, you have to create the secret again and
Repositorycrd manually. Follow the guide to understand
Repositorycrd structure from here.
We are going to recover our backed up data into a PVC. Rook Block Storage allows mounting Rook storage into pod using a
PersistentVolumeClaim. At first, we need to know respective StorageClass for Rook Block Storage.
$ kubectl get storageclass NAME PROVISIONER AGE rook-ceph-block ceph.rook.io/block 96m standard (default) k8s.io/minikube-hostpath 124m
rook-ceph-block storage class is responsible for provisioning the PVC from Rook Block Storage.
Let’s create a
rook-ceph-block storage class where our recovered data will be stored.
$ kubectl apply -f https://github.com/stashed/docs/raw/v2021.03.17/docs/examples/platforms/rook/rook-pvc.yaml persistentvolumeclaim/stash-recovered created
Below the YAML for
PersistentVolumeClaim we have created above,
apiVersion: v1 kind: PersistentVolumeClaim metadata: name: stash-recovered namespace: demo labels: app: stash-demo spec: storageClassName: rook-ceph-block accessModes: - ReadWriteOnce resources: requests: storage: 50Mi
Check that if cluster has provisioned the requested claim,
$ kubectl get pvc -n demo -l app=stash-demo kubectl get pvc -n demo -l app=stash-demo NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE stash-recovered Bound pvc-dd0739b2-f934-11e8-998e-080027a2d1ee 50Mi RWO rook-ceph-block 46s
Look at the
stash-recovered PVC is bounded to volume
Now, we have to create a
Recovery crd to recover backed up data into this PVC.
$ kubectl apply -f https://github.com/stashed/docs/raw/v2021.03.17/docs/examples/platforms/rook/recovery.yaml recovery.stash.appscode.com/rook-recovery created
Below, the YAML for
Recovery crd we have created above.
apiVersion: stash.appscode.com/v1alpha1 kind: Recovery metadata: name: rook-recovery namespace: demo spec: repository: name: deployment.stash-demo namespace: demo paths: - /source/data recoveredVolumes: - mountPath: /source/data persistentVolumeClaim: claimName: stash-recovered
Recovery job completes its task. To verify that recovery has completed successfully run,
$ kubectl get recovery -n demo rook-recovery NAME REPOSITORYNAMESPACE REPOSITORYNAME SNAPSHOT PHASE AGE rook-recovery demo deployment.stash-demo Succeeded 26s
Succeeded indicates that our recovery has been completed successfully. Backup data has been restored in
stash-recovered PVC. Now, we are ready to use this PVC to re-deploy the workload.
If you are using Kubernetes version older than v1.11.0 then run following command and check
status.phase field to see whether the recovery succeeded or failed.
$ kubectl get recovery -n demo rook-recovery -o yaml
We have successfully restored backed up data into
stash-recovered PVC. Now, we are going to re-deploy our previous deployment
stash-demo. This time, we are going to mount the
stash-recovered PVC as
source-data volume instead of ConfigMap
Below, the YAML for
stash-demo deployment with
stash-recovered PVC as
apiVersion: apps/v1 kind: Deployment metadata: labels: app: stash-demo name: stash-demo namespace: demo spec: replicas: 1 selector: matchLabels: app: stash-demo template: metadata: labels: app: stash-demo 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: stash-recovered
Let’s create the deployment,
$ kubectl apply -f https://github.com/stashed/docs/raw/v2021.03.17/docs/examples/platforms/rook/recovered-deployment.yaml deployment.apps/stash-demo created
Verify Recovered Data:
We have re-deployed
stash-demo deployment with recovered volume. Now, it is time to verify that the recovered data are present in
Get the pod of new deployment,
$ kubectl get pod -n demo -l app=stash-demo NAME READY STATUS RESTARTS AGE stash-demo-69694789df-rsrz6 1/1 Running 0 15s
Run following command to view data of
/source/data directory of this pod,
$ kubectl exec -n demo stash-demo-69694789df-rsrz6 -- ls -R /source/data source/data: LICENSE README.md lost+found /source/data/lost+found:
So, we can see that the data we had backed up from original deployment are now present in re-deployed deployment.
To cleanup the resources created by this tutorial, run following commands:
$ kubectl delete recovery -n demo rook-recovery $ kubectl delete secret -n demo rook-secret $ kubectl delete deployment -n demo stash-demo $ kubectl delete pvc -n demo stash-recovered $ kubectl delete repository -n demo deployment.stash-demo $ kubectl delete ns demo