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:
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
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)
