This topic describes how to use Velero to backup and restore a statefulset application with namespace.

Overview

This example demonstrates Velero backup and restore for a statefulset application with namespace. The CassandraDB app is used for demonstrating backup and restore with Velero.

When restoring a stateful application using Velero, the Storage Class that was used by the PVC in the application must be present on the Kubernetes cluster. If the PVC was using the default storage class, then the default storage class must also be present prior to initiating the restore operation with Velero.

Prerequisites

Install and configure Minio, Velero, and Restic.

The application we are going to use is the CassandraDB statefulset app. Download the CassandraDB YAML files to a local known directory:

  • cassandra-statefulset.yaml
  • cassandra-storageclass.yaml
  • headless-cassandra-service.yaml

Create the Storage Class

Modify the storage class cassandra-storageclass.yaml:

kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
  name: demo-sts-sc
provisioner: kubernetes.io/vsphere-volume
parameters:
  diskformat: thin

Apply the storage class YAML file:

kubectl apply -f cassandra-storageclass.yaml

storageclass.storage.k8s.io/demo-sts-sc created

Verify the storage class:

kubectl get sc
NAME          PROVISIONER                    RECLAIMPOLICY   VOLUMEBINDINGMODE   ALLOWVOLUMEEXPANSION   AGE

demo-sts-sc   kubernetes.io/vsphere-volume   Delete          Immediate           false                  3s

Deploy CassandraDB App

Create the namespace:

kubectl create ns cassandra

namespace/cassandra created

Create the service:

kubectl apply -f headless-cassandra-service.yaml -n cassandra

service/cassandra created

Deploy CassandraDB app:

kubectl apply -f cassandra-statefulset.yaml -n cassandra

statefulset.apps/cassandra created

Verify:

kubectl get all -n cassandra

NAME              READY   STATUS    RESTARTS   AGE
pod/cassandra-0   1/1     Running   0          5m16s
pod/cassandra-1   1/1     Running   0          4m25s
pod/cassandra-2   1/1     Running   0          2m52s

NAME                TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
service/cassandra   ClusterIP   None         <none>        <none>    5m21s

NAME                         READY   AGE
statefulset.apps/cassandra   3/3     5m16s
kubectl get pvc,pv -n cassandra

NAME                                               STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
persistentvolumeclaim/cassandra-data-cassandra-0   Bound    pvc-394770b3-64ba-4c35-af0c-f76a52695b25   100Gi      RWO            demo-sts-sc    5m46s
persistentvolumeclaim/cassandra-data-cassandra-1   Bound    pvc-5e0e4935-472e-46de-bba2-91d06d301f3b   100Gi      RWO            demo-sts-sc    4m55s
persistentvolumeclaim/cassandra-data-cassandra-2   Bound    pvc-cc4d55c4-b794-4a9f-871f-365ec0c3ad50   100Gi      RWO            demo-sts-sc    3m22s

NAME                                                        CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                                  STORAGECLASS   REASON   AGE
persistentvolume/pvc-394770b3-64ba-4c35-af0c-f76a52695b25   100Gi      RWO            Delete           Bound    cassandra/cassandra-data-cassandra-0   demo-sts-sc             5m46s
persistentvolume/pvc-5e0e4935-472e-46de-bba2-91d06d301f3b   100Gi      RWO            Delete           Bound    cassandra/cassandra-data-cassandra-1   demo-sts-sc             4m54s
persistentvolume/pvc-cc4d55c4-b794-4a9f-871f-365ec0c3ad50   100Gi      RWO            Delete           Bound    cassandra/cassandra-data-cassandra-2   demo-sts-sc             3m22s

Make sure CassandraDB instances are fully participating in the cluster:

kubectl exec -it cassandra-0 -n cassandra -- nodetool status

Datacenter: Demo-DataCenter
===========================
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
--  Address     Load       Tokens       Owns (effective)  Host ID                               Rack
UN  172.16.1.2  104.42 KiB  32           69.1%             6670d501-ce1a-41a6-b0ab-e5654be90d05  Demo-Rack
UN  172.16.1.3  75.87 KiB  32           60.8%             d4c65f54-6ba0-4caa-8b0c-9a2b945cb05c  Demo-Rack
UN  172.16.1.4  81.09 KiB  32           70.1%             fb0cca97-eb35-4e69-ad87-09ab18f739b2  Demo-Rack

Create and Populate a Database and Table in Cassandra

Create the DB:

kubectl exec -it cassandra-0 -n cassandra -- cqlsh

Connected to Demo-Cluster at 127.0.0.1:9042.
[cqlsh 5.0.1 | Cassandra 3.9 | CQL spec 3.4.2 | Native protocol v4]
Use HELP for help.

Create and populate table:

cqlsh> CREATE KEYSPACE demodb WITH REPLICATION = { ‘class’ : ‘SimpleStrategy’, ‘replication_factor’ : 3 }; cqlsh> use demodb; cqlsh:demodb> CREATE TABLE emp(emp_id int PRIMARY KEY, emp_name text, emp_city text, emp_sal varint,emp_phone varint); cqlsh:demodb> INSERT INTO emp (emp_id, emp_name, emp_city, emp_phone, emp_sal) VALUES (100, ‘Tom’, ‘Cork’, 999, 1000000); cqlsh:demodb> INSERT INTO emp (emp_id, emp_name, emp_city, emp_phone, emp_sal) VALUES (101, ‘Andrew’, ‘NY’, 1000, 1000000); cqlsh:demodb> INSERT INTO emp (emp_id, emp_name, emp_city, emp_phone, emp_sal) VALUES (102, ‘Lara’, ‘Paris’, 1001, 1000000); cqlsh:demodb> select * from emp;


Verify:

emp_id | emp_city | emp_name | emp_phone | emp_sal ——–+———-+———-+———–+——— 100 | Cork | Tom | 999 | 1000000 102 | Paris | Lara | 1001 | 1000000 101 | NY | Andrew | 1000 | 1000000

(3 rows)


Verify that the other Cassandra DB instances have the same information:

kubectl exec -it cassandra-1 -n cassandra – cqlsh

Connected to Demo-Cluster at 127.0.0.1:9042. [cqlsh 5.0.1 | Cassandra 3.9 | CQL spec 3.4.2 | Native protocol v4] Use HELP for help. cqlsh> use demodb; cqlsh:demodb> select * from emp;

emp_id | emp_city | emp_name | emp_phone | emp_sal ——–+———-+———-+———–+——— 100 | Cork | Tom | 999 | 1000000 102 | Paris | Lara | 1001 | 1000000 101 | NY | Andrew | 1000 | 1000000

(3 rows)


kubectl exec -it cassandra-2 -n cassandra – cqlsh

Connected to Demo-Cluster at 127.0.0.1:9042. [cqlsh 5.0.1 | Cassandra 3.9 | CQL spec 3.4.2 | Native protocol v4] Use HELP for help. cqlsh> use demodb; cqlsh:demodb> select * from emp;

emp_id | emp_city | emp_name | emp_phone | emp_sal ——–+———-+———-+———–+——— 100 | Cork | Tom | 999 | 1000000 102 | Paris | Lara | 1001 | 1000000 101 | NY | Andrew | 1000 | 1000000

(3 rows)


## <a id='cassandra-annotations'></a> Add Annotations

Add annotations for the stateful pods with the volume name `cassandra-data`.

kubectl get pod -n cassandra

NAME READY STATUS RESTARTS AGE cassandra-0 1/1 Running 0 19m cassandra-1 1/1 Running 0 19m cassandra-2 1/1 Running 0 17m


The pods `cassandra-0`, `cassandra-1` and `cassandra-2` must be annotated with `cassandra-data`.

kubectl -n cassandra annotate pod/cassandra-0 backup.velero.io/backup-volumes=cassandra-data pod/cassandra-0 annotated

kubectl -n cassandra annotate pod/cassandra-1 backup.velero.io/backup-volumes=cassandra-data pod/cassandra-1 annotated

kubectl -n cassandra annotate pod/cassandra-2 backup.velero.io/backup-volumes=cassandra-data pod/cassandra-2 annotated


Verify the annotations:

kubectl -n cassandra describe pod/cassandra-0 | grep Annotations Annotations: backup.velero.io/backup-volumes: cassandra-data

kubectl -n cassandra describe pod/cassandra-1 | grep Annotations Annotations: backup.velero.io/backup-volumes: cassandra-data

kubectl -n cassandra describe pod/cassandra-2 | grep Annotations Annotations: backup.velero.io/backup-volumes: cassandra-data


## <a id='cassandra-backup'></a> Backup the CassandraDB App using Namespace

Perform the Velero backup:

velero backup create cassandra-backup –include-namespaces cassandra

Backup request “cassandra-backup” submitted successfully. Run velero backup describe cassandra-backup or velero backup logs cassandra-backup for more details.


Verify the backup:

velero backup create cassandra-backup –include-namespaces cassandra

Backup request “cassandra-backup” submitted successfully. Run velero backup describe cassandra-backup or velero backup logs cassandra-backup for more details.


velero backup describe cassandra-backup –details Name: cassandra-backup Namespace: velero Labels: velero.io/storage-location=default Annotations: velero.io/source-cluster-k8s-gitversion=v1.17.8+vmware.1 velero.io/source-cluster-k8s-major-version=1 velero.io/source-cluster-k8s-minor-version=17

Phase: Completed

Velero-Native Snapshots:

Restic Backups: Completed: cassandra/cassandra-0: cassandra-data cassandra/cassandra-1: cassandra-data cassandra/cassandra-2: cassandra-data



Get the backup:

velero backup get

NAME STATUS ERRORS WARNINGS CREATED EXPIRES STORAGE LOCATION SELECTOR cassandra-backup Completed 0 0 2020-07-29 08:26:18 -0700 PDT 29d default


Use the Velero CRD commands to verify:

kubectl get crd


kubectl get backups.velero.io -n velero NAME AGE cassandra-backup 94s


kubectl describe backups.velero.io cassandra-backup -n velero


## <a id='cassandra-restore'></a> Restore the CassandraDB App

Restore the CassandraDB app from the Velero backup. Note the following about the restore operation:

- Pod annotation is still required for Velero backup of PV
- The namespace 'cassandra' was automatically re-created


Delete the namespace:

kubectl delete ns cassandra namespace “cassandra” deleted


Verify that Cassandra resources are deleted:

kubectl get ns

NAME STATUS AGE default Active 21d kube-node-lease Active 21d kube-public Active 21d kube-system Active 21d pks-system Active 21d velero Active 7d18h


kubectl get pvc,pv –all-namespaces No resources found


Verify that the storage class used by the application is still present:

kubectl get sc

NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE demo-sts-sc kubernetes.io/vsphere-volume Delete Immediate false 36m


Restore the CassandraDB app from the backup:

velero restore create –from-backup cassandra-backup

Restore request “cassandra-backup-20200729083742” submitted successfully. Run velero restore describe cassandra-backup-20200729083742 or velero restore logs cassandra-backup-20200729083742 for more details.


Verify that the app is restored:

velero restore describe cassandra-backup-20200729083742 Name: cassandra-backup-20200729083742 Namespace: velero Labels: Annotations:

Phase: Completed

Backup: cassandra-backup

Namespaces: Included: all namespaces found in the backup Excluded:

Resources: Included: * Excluded: nodes, events, events.events.k8s.io, backups.velero.io, restores.velero.io, resticrepositories.velero.io Cluster-scoped: auto

Namespace mappings:

Label selector:

Restore PVs: auto

Restic Restores (specify –details for more information): Completed: 3


velero restore get

NAME BACKUP STATUS ERRORS WARNINGS CREATED SELECTOR cassandra-backup-20200729083742 cassandra-backup Completed 0 0 2020-07-29 08:37:42 -0700 PDT


kubectl get ns

NAME STATUS AGE cassandra Active 80s default Active 21d kube-node-lease Active 21d kube-public Active 21d kube-system Active 21d pks-system Active 21d velero Active 7d18h


kubectl get all -n cassandra

NAME READY STATUS RESTARTS AGE pod/cassandra-0 1/1 Running 0 2m6s pod/cassandra-1 1/1 Running 2 2m6s pod/cassandra-2 1/1 Running 2 2m6s

NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/cassandra ClusterIP None 2m6s

NAME READY AGE statefulset.apps/cassandra 3/3 2m6s


Verify the persistent volume:

kubectl get pvc,pv -n cassandra


Check the content of each Cassandra DB instance:

kubectl exec -it cassandra-0 -n cassandra – cqlsh

Connected to Demo-Cluster at 127.0.0.1:9042. [cqlsh 5.0.1 | Cassandra 3.9 | CQL spec 3.4.2 | Native protocol v4] Use HELP for help. cqlsh> use demodb; cqlsh:demodb> select * from emp;

emp_id | emp_city | emp_name | emp_phone | emp_sal ——–+———-+———-+———–+——— 100 | Cork | Tom | 999 | 1000000 102 | Paris | Lara | 1001 | 1000000 101 | NY | Andrew | 1000 | 1000000

(3 rows)

kubectl exec -it cassandra-1 -n cassandra -- cqlsh

Connected to Demo-Cluster at 127.0.0.1:9042.
[cqlsh 5.0.1 | Cassandra 3.9 | CQL spec 3.4.2 | Native protocol v4]
Use HELP for help.
cqlsh> use demodb;
cqlsh:demodb> select * from emp;

 emp_id | emp_city | emp_name | emp_phone | emp_sal
--------+----------+----------+-----------+---------
    100 |     Cork |      Tom |       999 | 1000000
    102 |    Paris |     Lara |      1001 | 1000000
    101 |       NY |   Andrew |      1000 | 1000000

(3 rows)
kubectl exec -it cassandra-2 -n cassandra -- cqlsh

Connected to Demo-Cluster at 127.0.0.1:9042.
[cqlsh 5.0.1 | Cassandra 3.9 | CQL spec 3.4.2 | Native protocol v4]
Use HELP for help.
cqlsh> use demodb;
cqlsh:demodb> select * from emp;

 emp_id | emp_city | emp_name | emp_phone | emp_sal
--------+----------+----------+-----------+---------
    100 |     Cork |      Tom |       999 | 1000000
    102 |    Paris |     Lara |      1001 | 1000000
    101 |       NY |   Andrew |      1000 | 1000000

(3 rows)
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