Backing Up Your Kubernetes Applications with Velero v1.1

In this post, I’m going to walk through the process of installing and using Velero v1.1 to back up a Kubernetes application that includes persistent data stored in persisentvolumes. I will then simulate a DR scenario by completely deleting the application and using Velero to restore the application to the cluster, including the persistent data.

Meet Velero!! ⛵

Velero is a backup and recovery solution built specifically to assist in the backup (and migration) of Kubernetes applications, including their persistent storage volumes. You can even use Velero to back up an entire Kubernetes cluster for restore and/or migration! Velero address various use cases, including but not limited to:

• Taking backups of your cluster to allow for restore in case of infrastructure loss/corruption
• Migration of cluster resources to other clusters
• Replication of production cluster/applications to dev and test clusters

Velero is essentially comprised of two components:

• A server that runs as a set of resources with your Kubernetes cluster
• A command-line client that runs locally

Velero also supports the back up and restore of Kubernetes volumes using restic, an open source backup tool. Velero will need to utilize a S3 API-compatible storage server to store these volumes. To satisfy this requirement, I will also deploy a Minio server in my Kubernetes cluster so Velero is able to store my Kubernetes volume backups. Minio is a light weight, easy to deploy S3 object store that you can run on premises. In a production environment, you’d want to deploy your S3 compatible storage solution in another cluster or environment to prevent from total data loss in case of infrastructure failure.

Environment Overview

As a level set, I’d like to provide a little information about the infrastructure I am using in my lab environment. See below for infrastructure details:

• VMware vCenter Server Appliance 6.7u2
• VMware ESXi 6.7u2
• VMware NSX-T Datacenter 2.5.0
• VMware Enterprise PKS 1.5.0

Enterprise PKS handles the Day1 and Day2 operational requirements for deploying and managing my Kubernetes clusters. Click here for additional information on VMware Enterprise PKS.

However, I do want to mention that Velero can be installed and configured to interact with ANY Kubernetes cluster of version 1.7 or later (1.10 or later for restic support).

Installing Minio

First, I’ll deploy all of the components required to support the Velero service, starting with Minio.

First things first, I’ll create the velero namespace to house the Velero installation in the cluster:

$ kubectl create namespace velero

I also decided to create a dedicated storageclass for the Minio service to use for its persistent storage. In Enterprise PKS Kubernetes clusters, you can configure the vSphere Cloud Provider plugin to dynamically create VMDKs in your vSphere environment to support persistentvolumes whenever a persistentvolumeclaim is created in the Kubernetes cluster. Click here for more information on the vSphere Cloud Provider plugin:

$ kubectl create -f minio-storage-class.yaml 


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

Now that we have a storage class, I’m ready to create a persistentvolumeclaim the Minio service will use to store the volume backups via restic. As you can see from the example .yaml file below, the previously created storageclass is referenced to ensure the persistentvolume is provisioned dynamically:

$ cat minio-pvc.yaml

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: velero-claim
  namespace: velero
  annotations:
    volume.beta.kubernetes.io/storage-class: minio-disk
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 10Gi


$ kubectl create -f minio-pvc.yaml

Verify the persistentvolumeclaim was created and its status is Bound:

$ kubectl get pvc -n velero

NAME          STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
minio-claim   Bound    pvc-cc7ac855-e5f0-11e9-b7eb-00505697e7e7   6Gi        RWO            minio-disk     8s

Now that I’ve created the storage to support the Minio deployment, I am ready to create the Minio deployment. Click here for access to the full .yaml file for the Minio deployment:

$ kubectl create -f minio-deploy.yaml 

deployment.apps/minio created
service/minio created
secret/cloud-credentials created
job.batch/minio-setup created
ingress.extensions/velero-minio created

Use kubectl to wait for the minio-xxxx pod to enter the Running status:

$ kubectl get pods -n velero -w

NAME                    READY   STATUS              RESTARTS   AGE
minio-754667444-zc2t2   0/1     ContainerCreating   0          4s
minio-setup-skbs6       1/1     Running             0          4s
NAME                    READY   STATUS              RESTARTS   AGE
minio-754667444-zc2t2   1/1     Running             0          9s
minio-setup-skbs6       0/1     Completed           0          11s

Now that our Minio application is deployed, we need to expose the Minio service to requests outside of the cluster via a LoadBalancer service type with the following command:

$ kubectl expose deployment minio --name=velero-minio-lb --port=9000 --target-port=9000 --type=LoadBalancer --namespace=velero

Note, because of the integration between VMware Enterprise PKS and VMware NSX-T Datacenter, when I create a “LoadBalancer” service type in the cluster, the NSX Container Plugin, which we are using as our Container Network Interface, reaches out to the NSX-T API to automatically provision a virtual server in a NSX-T L4 load balancer.

I’ll use kubectl to retrieve the IP of the virtual server created within the NSX-T load balancer and access the Minio UI in my browser at EXTERNAL-IP:9000 I am looking for the IP address under the EXTERNAL-IP section for the velero-minio-lb service, 10.96.59.116 in this case:

$ kubectl get services -n velero

NAME              TYPE           CLUSTER-IP       EXTERNAL-IP    PORT(S)          AGE
minio             ClusterIP      10.100.200.160   <none>         9000/TCP         7m14s
velero-minio-lb   LoadBalancer   10.100.200.77    10.96.59.116   9000:30711/TCP   12s

Now that Minio has been succesfully deployed in the my Kubernetes cluster, I’m ready to move on to the next section to install and configure Velero and restic.

Installing Velero and Restic

Now that I have an s3-compatible storage solution deployed in my environment, I am ready to complete the installation of Velero (and restic).

However, before I move forward with the installation of Velero, I need to install the Velero CLI client on my workstation. The instructions detailed below will allow you to install the client on a Linux server (I’m using a CentOS 7 instance).

First, I navigated to the Velero github releases page and copied the link for the v1.1 .rpm file for my OS distribution:

Then, I used wget to pull the image down to my linux server, extracted the contents of the file, and moved the velero binary into my path:

$ cd ~/tmp

$ wget https://github.com/vmware-tanzu/velero/releases/download/v1.1.0/velero-v1.1.0-linux-amd64.tar.gz

$ tar -xvf https://github.com/vmware-tanzu/velero/releases/download/v1.1.0/velero-v1.1.0-linux-amd64.tar.gz

$ sudo mv velero-v1.1.0-linux-amd64/velero /usr/bin/velero

Now that I have the Velero client installed on my server, I am ready to continue with the installation.

I’ll create a credentials-velero file that we will use during install to authenticate against the Minio service. Velero will use these credentials to access Minio to store volume backups:

$ cat credentials-velero

[default]
aws_access_key_id = minio
aws_secret_access_key = minio123

Now I’m ready to install Velero! The following command will complete the installation of Velero (and restic) where:

• --provider aws instructs Velero to utilize S3 storage which is running on-prem, in my case
• --secret-file is our Minio credentials
• --use-restic flag ensures Velero knows to deploy restic for persistentvolume backups

• --s3Url value is the address of the Minio service that is only resolvable from within the Kubernetes cluster * --publicUrl value is the IP address for the LoadBalancer service that allows access to the Minio UI from outside of the cluster:

  $ velero install –provider aws –bucket velero –secret-file credentials-velero \ –use-volume-snapshots=false –use-restic –backup-location-config \ region=minio,s3ForcePathStyle=”true”,s3Url=http://minio.velero.svc:9000,publicUrl=http://10.96.59.116:9000

  Velero is installed! ⛵ Use ‘kubectl logs deployment/velero -n velero’ to view the status.

Note: The velero install command creates a set of CRDs that power the Velero service. You can run velero install --dry-run -o yaml to output all of the .yaml files used to create the Velero deployment.

After the installation is complete, I’ll verify that I have 3 restic-xxx pods and 1 velero-xxx pod deployed in the velero namespace. As the restic service is deployed as a daemonset, I will expect to see a restic pod per node in my cluster. I have 3 worker nodes so I should see 3 restic pods:

Note: Notice the status of the restic-xxx pods…

$ kubectl get pod -n velero
NAME                      READY   STATUS             RESTARTS   AGE
minio-5559c4749-7xssq     1/1     Running            0          7m21s
minio-setup-dhnrr         0/1     Completed          0          7m21s
restic-mwgsd              0/1     CrashLoopBackOff   4          2m17s
restic-xmbzz              0/1     CrashLoopBackOff   4          2m17s
restic-235cz              0/1     CrashLoopBackOff   4          2m17s
velero-7d876dbdc7-z4tjm   1/1     Running            0          2m17s

As you may notice, the restic pods are not able to start. That is because in Enterprise PKS Kubernetes clusters, the path to the pods on the nodes is a little different (/var/vcap/data/kubelet/pods) than in “vanilla” Kubernetes clusters (/var/lib/kubelet/pods). In order to allow the restic pods to run as expected, I’ll need to edit the restic daemon set and change the hostPath variable as referenced below:

$ kubectl edit daemonset restic -n velero


volumes:
      - hostPath:
          path: /var/vcap/data/kubelet/pods
          type: ""
        name: host-pods

Now I’ll verify all of the restic pods are in Running status:

$ kubectl get pod -n velero

NAME                      READY   STATUS      RESTARTS   AGE
minio-5559c4749-7xssq     1/1     Running     0          12m
minio-setup-dhnrr         0/1     Completed   0          12m
restic-p4d2c              1/1     Running     0          6s
restic-xvxkh              1/1     Running     0          6s
restic-e31da              1/1     Running     0          6s
velero-7d876dbdc7-z4tjm   1/1     Running     0          7m36s

Woohoo!! Velero is successfully deployed in my Kubernetes clusters. Now I’m ready to take some backups!!

Backup/Restore the WordPress Application using Velero

Now that I’ve deployed Velero and all of its supporting components in my cluster, I’m ready to perform some backups. But in order to taste my backup/recovery solution, I’ll need an app that preferably utilizes persistent data.

In one of my previous blog posts, I walked through the process of deploying Kubeapps in my cluster to allow me to easily deploy application stacks to my Kubernetes cluster.

For this exercise, I’ve used Kubeapps to deploy a WordPress blog that utilizes persistentvolumes to store post data for my blog. I’ve also populated the blog with a test post to test backup and recovery.

First, I’ll verify that the WordPress pods are in a Running state:

$ kubectl get pods -n wordpress

NAME                                  READY   STATUS    RESTARTS   AGE
cut-birds-mariadb-0                   1/1     Running   0          23h
cut-birds-wordpress-fbb7f5b76-lm5bh   1/1     Running   0          23h

I’ll also verify the URL of my blog and access it via my web browser to verify current state:

$ kubectl get svc -n wordpress

NAME                  TYPE           CLUSTER-IP      EXTERNAL-IP    PORT(S)                      AGE
cut-birds-mariadb     ClusterIP      10.100.200.39   <none>         3306/TCP                     19h
cut-birds-wordpress   LoadBalancer   10.100.200.32   10.96.59.116   80:32393/TCP,443:31585/TCP   19h

Everything looks good, especially the cat!!

In order for Velero to understand where to look for persistent data to back up, in addition to other Kubernetes resources in the cluster, we need to annotate each pod that is utilizing a volume so Velero backups up the pods AND the volumes.

I’ll review both of the pods in the wordpress namespace to view the name of each volume being used by each pod:

$ kubectl describe pod/cut-birds-mariadb-0 -n wordpress

---output omitted---

Volumes:
  data:
    Type:       PersistentVolumeClaim (a reference to a PersistentVolumeClaim in the same namespace)
    ClaimName:  data-cut-birds-mariadb-0
    ReadOnly:   false
  config:
    Type:      ConfigMap (a volume populated by a ConfigMap)
    Name:      cut-birds-mariadb
    Optional:  false
  default-token-6q5xt:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-6q5xt
    Optional:    false


$ kubectl describe pods/cut-birds-wordpress-fbb7f5b76-lm5bh -n wordpress

---output omitted---

Volumes:
  wordpress-data:
    Type:       PersistentVolumeClaim (a reference to a PersistentVolumeClaim in the same namespace)
    ClaimName:  cut-birds-wordpress
    ReadOnly:   false
  default-token-6q5xt:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-6q5xt
    Optional:    false

As you can see, the mariadb pod is using 2 volumes: data and config, while the wordpress pod is utilizing a single volume: wordpress-data.

I’ll run the following commands to annotate each pod with the backup.velero.io tag with each pods’ corresponding volume(s):

$ kubectl -n wordpress annotate pod/cut-birds-mariadb-0 backup.velero.io/backup-volumes=data,config
$ kubectl -n wordpress annotate pod/cut-birds-wordpress-fbb7f5b76-lm5bh backup.velero.io/backup-volumes=wordpress-data

Now I’m ready to use the velero client to create a backup. I’ll name the backup wordpress-backup and ensure the backup only includes the resources in the wordpress namespace:

$ velero backup create wordpress-backup --include-namespaces wordpress

Backup request "wordpress-backup" submitted successfully.
Run `velero backup describe wordpress-backup` or `velero backup logs wordpress-backup` for more details.

I can also use the velero client to ensure the backup is compeleted by waiting for Phase: Complete:

$ velero backup describe wordpress-backup

Name:         wordpress-backup
Namespace:    velero
Labels:       velero.io/storage-location=default
Annotations:  <none>

Phase:  Completed

--output omitted--

I’ll navigate back to the web browser and refresh (or log back into) the Minio UI. Notice the restic folder, which holds houses our backups persistent data, as well as a backups folder:

I’ll select the backups folder and note the wordpress-backup folder in the subsequent directory. I’ll also explore the contents of the wordpress-backup folder, which contains all of the Kubernetes resources from mywordpress namespace:

Now that I’ve confirmed my backup was successful and have verified the data has been stored in Minio via the web UI, I am ready to completely delete my WordPress application. I will accomplish this by deleting the wordpress namespace, which will delete all resources created in the namespace to support the WordPress application, even the persistentvolumeclaims

$ kubectl delete namespace wordpress


$ kubectl get pods -n wordpress
$ kubectl get pvc -n wordpress

After I’ve confirmed all of the resources in the wordpress namespace have been deleted, I’ll refresh the browser to verify the blog is no longer available.

Now we’re ready to backup!! I’ll use the velero client to verify the existence/name of the backup that was previously created and restore the backup to the cluster:

$ velero backup get

NAME               STATUS      CREATED                         EXPIRES   STORAGE LOCATION   SELECTOR
wordpress-backup   Completed   2019-10-03 15:47:07 -0400 EDT   29d       default            <none>


$ velero restore create --from-backup wordpress-backup

I can monitor the pods in the wordpress namespace and wait for both pods to show 1/1 in the READY column and Running in the STATUS column:

$ kubectl get pods -n wordpress -w

NAME                                  READY   STATUS     RESTARTS   AGE
cut-birds-mariadb-0                   0/1     Init:0/1   0          12s
cut-birds-wordpress-fbb7f5b76-qtcpp   0/1     Init:0/1   0          13s
cut-birds-mariadb-0                   0/1     PodInitializing   0          18s
cut-birds-mariadb-0                   0/1     Running           0          19s
cut-birds-wordpress-fbb7f5b76-qtcpp   0/1     PodInitializing   0          19s
cut-birds-wordpress-fbb7f5b76-qtcpp   0/1     Running           0          20s
cut-birds-mariadb-0                   1/1     Running           0          54s
cut-birds-wordpress-fbb7f5b76-qtcpp   1/1     Running           0          112s

Then, I can verify the URL of the WordPress blog:

$ kubectl get services -n wordpress

NAME                  TYPE           CLUSTER-IP      EXTERNAL-IP    PORT(S)                      AGE
cut-birds-mariadb     ClusterIP      10.100.200.39   <none>         3306/TCP                     2m56s
cut-birds-wordpress   LoadBalancer   10.100.200.32   10.96.59.120   80:32393/TCP,443:31585/TCP   2m56s

And finally, I can access the URL of the blog in the web broswer, confirm the test post that was visible initially is still present:

There you have it!! Our application and it’s persistent data have been completely restored!!

In this example, we manually created a backup, but we can also use the Velero client to schedule backups on a certain interval. See examples below:

velero schedule create planes-daily --schedule="0 1 * * *" --include-namespaces wordpress
velero schedule create planes-daily --schedule="@daily" --include-namespaces wordpress

Conclusion

In this blog post, I walked through the process of installing Velero in a Kubernetes cluster, including all it’s required components, to support taking backups of Kubernetes resources. I also walked through the process for taking a backup, simulating a data loss scenario, and restoring that backup to the cluster.