Configure AWS EBS Storage for KubernetesEstimated reading time: 3 minutes
AWS Elastic Block Store (EBS) can be deployed with Kubernetes in Docker Enterprise 2.1 to use AWS volumes as peristent storage for applications. Before using EBS volumes, configure UCP and the AWS infrastructure for storage orchestration to function.
Configure AWS Infrastructure for Kubernetes
Kubernetes Cloud Providers provide a method of provisioning cloud resources through Kubernetes via the
--cloud-provider option. In AWS, this flag allows the provisioning of EBS volumes and cloud load balancers.
Configuring a cluster for AWS requires several specific configuration parameters in the infrastructure before installing UCP.
AWS IAM Permissions
Instances must have the following AWS Identity and Access Management permissions configured to provision EBS volumes through Kubernetes PVCs.
- Apply the roles and policies to Kubernetes masters and workers as indicated in the above chart.
- Set the hostname of the EC2 instances to the private DNS hostname of the instance. See DNS Hostnames and To change the system hostname without a public DNS name for more details.
- Label the EC2 instances with the key
KubernetesClusterand assign the same value across all nodes, for example,
- In addition to your existing install flags the cloud provider flag
--cloud-provider=awsis required at install time.
- The cloud provider can also be enabled post-install through the UCP config. The
ucp-agentneeds to be updated to propogate the new config, as described in UCP configuration file.
[cluster_config] ... cloud_provider = "aws"
Deploy AWS EBS Volumes
After configuring UCP for the AWS cloud provider, you can create persistent volumes that deploy EBS volumes attached to hosts and mounted inside pods. The EBS volumes are provisioned dynamically such they are created, attached, destroyed along with the lifecycle of the persistent volumes. This does not require users to directly access to the AWS as you request these resources directly through Kubernetes primitives.
We recommend you use the
PersistentVolumeClaim resources as these abstraction layers provide more portability as well as control over the storage layer across environments.
To learn more about storage concepts in Kubernetes, see Storage - Kubernetes.
Creating a Storage Class
StorageClass lets administrators describe “classes” of storage available in which classes map to quality-of-service levels, or backup policies, or any policies required by cluster administrators. The following
StorageClass maps a “standard” class of storage to the
gp2 type of storage in AWS EBS.
kind: StorageClass apiVersion: storage.k8s.io/v1 metadata: name: standard provisioner: kubernetes.io/aws-ebs parameters: type: gp2 reclaimPolicy: Retain mountOptions: - debug
For descriptions of AWS EBS parameters, see Storage Classes.
Creating a Persistent Volume Claim
PersistentVolumeClaim (PVC) is a claim for storage resources that are bound to a
PersistentVolume (PV) when storage resources are granted. The following PVC makes a request for
1Gi of storage from the
standard storage class.
kind: PersistentVolumeClaim apiVersion: v1 metadata: name: task-pv-claim spec: storageClassName: standard accessModes: - ReadWriteOnce resources: requests: storage: 1Gi
Deploying a Persistent Volume
The following Pod spec references the PVC
task-pv-claim from above which references the
standard storage class in this cluster.
kind: Pod apiVersion: v1 metadata: name: task-pv-pod spec: volumes: - name: task-pv-storage persistentVolumeClaim: claimName: task-pv-claim containers: - name: task-pv-container image: nginx ports: - containerPort: 80 name: "http-server" volumeMounts: - mountPath: "/usr/share/nginx/html" name: task-pv-storage
Inspecting and Using PVs
Once the pod is deployed, run the following
kubectl command to verify the PV was created and bound to the PVC.
kubectl get pv NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE pvc-751c006e-a00b-11e8-8007-0242ac110012 1Gi RWO Retain Bound default/task-pv-claim standard 3h
The AWS console shows a volume has been provisioned having a matching name with type
gp2 and a
UCP, Docker Enterprise, Kubernetes, storage, AWS, ELB