OpenEBS on DigitalOcean Marketplace – MayaData Help Center

Deploying OpenEBS on DigitalOcean can directly be done from the console. DigitalOcean provides the feature to create a cluster with OpenEBS deployed on it already. To get started, follow the below-mentioned steps:

WORKFLOW

STEP 1

Getting started

STEP 2

Creation of cluster

Once you log in, you arrive at the dashboard, click on Marketplace under DISCOVER located on the left sidebar.

Next, scroll down to find OpenEBS, clicking on it you will be redirected to a page where you will find details about OpenEBS and Create OpenEBS button in the right side.

Next, you need to provide the necessary details such as Data Center region, cluster capacity, cluster name etc. (It is advisable to provision 3 nodes with 4vCPUs and 8 GB memory to ensure that the resources are sufficient at all times. )

STEP 3

Connecting your cluster

Creation, resizing and deletion can be carried out from UI but to perform administrative tasks you require command-line tools from your local machine or a remote management server. The detailed steps to install the management tools and connect the cluster to your local machine can be found under the Overview section.

To verify execute the following command,

$ kubectl get ns

Output:

NAME     STATUS    AGE
default  Active    13m
openebs  Active    13m

The output must contain openebs ns in Active state.

Next, execute

$ kubectl get pods -n openebs

Output:

NAME                                                 READY     STATUS    RESTARTS AGE
openebs-admission-server-5c4d545647-r4vgr            1/1       Running   0        13m
openebs-apiserver-56f77c9965-xft68                   1/1       Running   2        13m
openebs-localpv-provisioner-64c67b5b89-czv8b         1/1       Running   0        13m
openebs-ndm-5f6nt                                    1/1       Running   0        13m
openebs-ndm-74njq                                    1/1       Running   0        13m
openebs-ndm-operator-7bc769dcff-b45bc                1/1       Running   1        13m
openebs-ndm-spttv                                    1/1       Running   0        13m
openebs-provisioner-755f465f9d-fr67l                 1/1       Running   0        13m
openebs-snapshot-operator-7988fc8646-zpd98           2/2       Running   0        13m

All the pods must be in running state.

STEP 4

Attaching BlockDevices

To attach BlockDevices to the created nodes click on Volumes on the left sidebar and then click on Add Volume button.

Next, select the volume size ( provision at least 30 GB), select the node(droplet) to which it gets attached and provide a name, then click on Create Volume button. Repeat these steps for each node (droplet).

NOTE:
For cStor, choose Manually Mount and Format under Choose Configuration Options.
For Jiva, choose Automatically Format and Mount under Choose Configuration Options.

For cStor

For Jiva

After the BlockDevices get attached for all the nodes you can see an output similar to the below image.

Provisioning OpenEBS volumes

Next, you have to provision OpenEBS volumes (cStor or Jiva or LocalPV). Going through the following links can help you decide as to which will be best suited for your scenario.

Click here to know about cStor.

Click here to know about Jiva.

Click here to know about LocalPV.

First, Create a cStorPool

For creation of a cStorPool you will need to specify the blockdevices, to view the disks attached execute the following command

kubectl get blockdevice -n <openebs_namespace>

The output looks something like this:

NAME                                         NODEN              SIZE         CLAIMSTATE  STATUS  AGE
blockdevice-66a74896b61c60dcdaf7c7a76fde0ebb pool-152c1305-x7s8 42949672960  Unclaimed   Active  2m 
blockdevice-b34b3f97840872da9aa0bac1edc9578a pool-c36a00d4-549p 42949672960  Unclaimed   Active  2m
blockdevice-ce41f8f5fa22acb79ec56292441dc207 pool-25b9dd3a-kgq5 42949672960  Unclaimed   Active  2m

Now, copy the below snippet with your blockdevices specified in a file, say cstor-pool-config.yaml

apiVersion: openebs.io/v1alpha1
kind: StoragePoolClaim
metadata:
  name: cstor-disk-pool
  annotations:
    cas.openebs.io/config: |
      - name: PoolResourceRequests
        value: |-
            memory: 2Gi
      - name: PoolResourceLimits
        value: |-
            memory: 4Gi
spec:
  name: cstor-disk-pool
  type: disk
  poolSpec:
    poolType: striped
  blockDevices:
    blockDeviceList:
    ## Replace the following with actual blockDevice CRs from your cluster using "kubectl get bd -n openebs" 
    - blockdevice-66a74896b61c60dcdaf7c7a76fde0ebb
    - blockdevice-b34b3f97840872da9aa0bac1edc9578a
    - blockdevice-ce41f8f5fa22acb79ec56292441dc207
---

Now, apply the above yaml file using the following command:

kubectl apply -f cstor-pool-config.yaml

To verify execute :

kubectl get spc

The output should have a cStor-pool created

NAME              AGE
cstor-disk-pool   1m

Next, You have to create a StorageClass
Copy the yaml given below in a file,say cstor-sc.yaml

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: openebs-sc-statefulset
  annotations:
    openebs.io/cas-type: cstor
    cas.openebs.io/config: |
      - name: StoragePoolClaim
        value: "cstor-disk-pool"
      - name: ReplicaCount
        value: "3"
      - name: ReplicaAntiAffinityTopoKey
        value: failure-domain.beta.kubernetes.io/zone    
provisioner: openebs.io/provisioner-iscsi

Now, apply the above yaml file using the following command:

kubectl apply -f cstor-sc.yaml

To verify execute:

kubectl get sc

The output must contain the StorageClass name specified in the yaml file.

NAME                     PROVISIONER                         AGE
openebs-sc-statefulset   openebs.io/provisioner-iscsi        1m

Next, you need a PVC spec or volumeClaimTemplate to use the StorageClass that is pointing to a pool with real disks. The PVC is included in the application spec for the example given in STEP 6. It is mentioned here for a clearer understanding.

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: cstor-pvc-mysql-large
spec:
  storageClassName: openebs-sc-statefulset
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 500Gi

The below spec represents the YAML spec for jiva, it has already been included in application spec provided in STEP 6. It is mentioned here for a clearer understanding.

    kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: demo-vol1-claim
spec:
  storageClassName: openebs-jiva-default
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 4G

You can also provision it with Local or Cloud Disks to know more click here.

LocalPVs are provisioned dynamically by OpenEBS LocalPV provisioner. LocalPV with default StorageClass can be provisioned with storage-type as device or hostpath. LocalPV gets provisioned dynamically on the node after the application is provisioned. This is ensured by adding volumeBindingMode: WaitForFirstConsumer in the yaml file

As the LocalPV gets provisioned on the node where the application is present, to have multi-zone cluster ensure the application get replicated on the desired nodes.
You can refer the following links to view the yaml file for provisioning LocalPV

STEP 6

Provisioning an application.

Now, things are all set to deploy an application and get started.

You can refer to the below sample articles for provisioning an application.

1. Sample application for cStor.

2. Sample application for Jiva.

3. Sample application for Local PV.

STEP 7

Backing up Application

It is extremely important to have a data backup and restore mechanism so that the service continues flawlessly in every situation.

Backup and Restore for cStor can be done using DMaaS, a solution for data agility and data motion in Kubernetes platform. DMaaS being application aware ensures that the state of application remains consistent before and after migration, also the time taken to restore the operations back to normal mode is quite optimised.
DMaaS is an offering from MayaData that works with both Director Online as well as OnPrem. To know more about configuring DMaaS with your cluster click here.

For applications provisioned using LocalPV and Jiva volume, restore and backup can be done using Velero. Velero provides tools to backup and restore Kubernetes cluster resources and persistent volume. Velero gives you tools to back up and restore your Kubernetes cluster resources and persistent volumes. Using Velero you can:

Take backups of your cluster and restore in case of loss.
Migrate cluster resources to other clusters.
Replicate your production cluster to development and testing clusters.

You can run Velero in clusters on a cloud provider or on-premises.
To know the steps to create and manage backups of jiva volume using Velero Click Here.
To know the steps to create and manage backups of LoacalPV using Velero Click Here.

STEP 8

Monitoring of stateful applications and OpenEBS volumes

Once the entire thing is set up, volumes are provisioned, the application is deployed it is necessary to monitor these components continuously. Director provides easy and efficient monitoring. To know about how to monitor, different monitoring views click here.

OpenEBS volumes can be deployed on various other Kubernetes Platforms as well, to know about it Click Here.

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