#HPENimbleStorage

[datamattsson]

Kubernetes 1.16 released

Finally it’s the weekend. Peace and quiet to indulge yourself in a new Kubernetes release! Many others have beat me to it, great overviews are available from various sources.

The most exciting thing for me in Kubernetes 1.16 is the graduation of many alpha CSI features to beta. This is removes the friction of tinkering with the feature gates on either the kubelet or API server which is pet peeve of mine and makes me moan out loud when I found out something doesn't work because of it.

TL;DR

All these features have already been demonstrated with the HPE CSI Driver for Kubernetes, it starts about 7 minutes in, I’ve fast forwarded it for you.

At the Helm

Let’s showcase these graduated features with the newly released HPE CSI Driver for Kubernetes. Be warned, issues ahead. Helm is not quite there yet on Kubernetes 1.16, a fix to deploy Tiller on your cluster is available here. Next issue up is that the HPE CSI Driver Helm chart is not yet compatible with Kubernetes 1.16. I’m graciously and temporarily hosting a copy on my GitHub account.

Create a values.yaml file:

backend: 192.168.1.10 # This is your Nimble array username: admin password: admin servicePort: "8080" serviceName: nimble-csp-svc fsType: xfs accessProtocol: "iscsi" storageClass: create: false

Helm your way on your Kubernetes 1.16 cluster:

helm repo add hpe https://drajen.github.io/co-deployments-116 helm install --name hpe-csi hpe/hpe-csi-driver --namespace kube-system -f values.yaml

In my examples repo I’ve dumped a few declarations that I used to walk through these features. When I'm referencing a YAML file name, this is where to find it.

VolumePVCDataSource

This is a very useful capability when you’re interested in creating a clone of an existing PVC in the current state. I’m surprised to see this feature mature to beta before VolumeSnapshotDataSource which has been around for much longer.

Assuming you have an existing PVC named “my-pvc”:

apiVersion: v1 kind: PersistentVolumeClaim metadata: name: my-pvc-clone spec: accessModes: - ReadWriteOnce resources: requests: storage: 32Gi dataSource: kind: PersistentVolumeClaim name: my-pvc storageClassName: my-storageclass

Let’s cuddle:

$ kubectl create -f pvc.yaml persistentvolumeclaim/my-pvc created $ kubectl create -f pvc-clone.yaml persistentvolumeclaim/my-pvc-clone created $ kubectl get pvc NAME STATUS VOLUME CAPACITY STORAGECLASS AGE my-pvc Bound pvc-ae0075... 10Gi my-storageclass 34s my-pvc-clone Bound pvc-d5eb6f... 10Gi my-storageclass 14s

On the Nimble array, we can indeed observe we have a clone of the dataSource.

ExpandCSIVolumes and ExpandInUsePersistentVolumes

This is indeed a very welcome addition to be promoted. Among the top complaints from users. This is stupid easy to use. Simply edit or patch your existing PVC to expand your PV.

$ kubectl patch pvc/my-pvc-clone -p '{"spec": {"resources": {"requests": {"storage": "32Gi"}}}}' persistentvolumeclaim/my-pvc-clone patched $ kubectl get pv NAME CAPACITY CLAIM STORAGECLASS AGE pvc-d5eb6... 32Gi default/my-pvc-clone my-storageclass 9m25s

Yes, you can expand clones, no problem.

CSIInlineVolume

On of my favorite features of our legacy FlexVolume is the ability to create Inline Ephemeral Clones for CI/CD pipelines. Creating a point in time copy of a volume, do some work and/or tests on it and dispose of it. Leave no trace behind.

If this is something you’d like to walk through, there’s a few prerequisite steps here. The Helm chart does not create the CSIDriver custom resource definition (CRD). It need to be applied first:

apiVersion: storage.k8s.io/v1beta1 kind: CSIDriver metadata: name: csi.hpe.com spec: podInfoOnMount: true volumeLifecycleModes: - Persistent - Ephemeral

Next, the current behavior (subject to change) is that you need a secret for the CSI driver in the namespace you’re deploying to. This is a oneliner to copy from “kube-system” to your current namespace.

$ kubectl get -nkube-system secret/nimble-secret -o yaml | \ sed -e 's/namespace: kube-system//' | \ kubectl create -f-

Now, assuming we have deployed a MariaDB and have that running elsewhere. This example clones the actual Nimble volume. In essence, the volume may reside on a different Kubernetes cluster or hosted on a bare-metal server or virtual machine.

For clarity, the Deployment I’m cloning this volume from is using a secret, I’m using that same secret hosted in dep.yaml.

apiVersion: v1 kind: Pod metadata: name: mariadb-ephemeral spec: spec: containers: - image: mariadb:latest name: mariadb env: - name: MYSQL_ROOT_PASSWORD valueFrom: secretKeyRef: name: mariadb key: password ports: - containerPort: 3306 name: mariadb volumeMounts: - name: mariadb-persistent-storage mountPath: /var/lib/mysql volumes: - name: mariadb-persistent-storage csi: driver: csi.hpe.com nodePublishSecretRef: name: nimble-secret volumeAttributes: cloneOf: pvc-ae007531-e315-4b81-b708-99778fa1ba87

The magic sauce here is of course the .volumes.csi stanza where you specify the driver and your volumeAttributes. Any Nimble StorageClass parameter is supported in volumeAttributes.

Once, cuddled, you can observe the volume on the Nimble array.

CSIBlockVolume

I’ve visited this feature before in my Frankenstein post where I cobbled together a corosync and pacemaker cluster running as a workload on Kubernetes backed by a ReadWriteMany block device.

A tad bit more mellow example is the same example we used for the OpenShift demos in the CSI driver beta video (fast forwarded).

Creating a block volume is very simple (if the driver supports it). By default volumes are created with the attribue volumeMode: Filesystem. Simply switch this to Block:

apiVersion: v1 kind: PersistentVolumeClaim metadata: name: my-pvc-block spec: accessModes: - ReadWriteOnce resources: requests: storage: 32Gi volumeMode: Block storageClassName: my-storageclass

Once cuddled, you may reference the PVC as any other PVC, but pay attention to the .spec.containers stanza:

apiVersion: v1 kind: Pod metadata: name: my-pod spec: containers: - name: ioping image: hpestorage/ioping command: [ "ioping" ] args: [ "/dev/xvda" ] volumeDevices: - name: data devicePath: /dev/xvda volumes: - name: data persistentVolumeClaim: claimName: my-pvc-block

Normally you would specify volumeMounts and mountPath for a PVC created with volumeMode: Filesystem.

Running this particular Pod using ioping would indeed indicate that we connected a block device:

kubectl logs my-pod -f 4 KiB <<< /dev/xvda (block device 32 GiB): request=1 time=3.71 ms (warmup) 4 KiB <<< /dev/xvda (block device 32 GiB): request=2 time=1.73 ms 4 KiB <<< /dev/xvda (block device 32 GiB): request=3 time=1.32 ms 4 KiB <<< /dev/xvda (block device 32 GiB): request=4 time=1.06 ms ^C

For competitors who landed on this blog in awe looking for Nimble weaknesses, the response time you see above is a Nimble Virtual Array running on my five year old laptop.

So, that was “it” for our graduated storage features! I'm looking forward to Kubernetes 1.17 already.

Release mascot!

I’m a sucker for logos and mascots. Congrats to the Kubernetes 1.16 release team.

[datamattsson]

I'm co-presenting another talk next week at HPE Aspire covering our persistent storage integration with Red Hat OpenShift on the Reference Architecture with HPE Synergy.

Learn how HPE delivers an end-to-end turnkey solution. Full abstract:

Enterprise customers are increasingly adopting container technology as part of their application and infrastructure modernization plans, and as a critical component of their DevOps environment. Many of these customers are looking at Red Hat OpenShift as the underlying PaaS and container ecosystem to host their next generation applications. On this session, you will hear how you can leverage the joint solution we are building with Red Hat to effectively target this market. Learn about the OpenShift dev to ops solution on HPE Synergy and Composable Cloud for Proliant DLs. And how we can target small configurations for low cost POCs and DevOps teams, and large scalable configurations for production deployment. Some of these solution also includes a choice of 3PAR or Nimble for persistent storage support, and all the enterprise level data protection they can provide for containers. You will also learn about the types of PointNext services we can offer to help customers transition to containers and OpenShift.

Thursday 8am sharp! Sign up!

[datamattsson]

Besides chasing alligators next week in Orlando at HPE Aspire, I'll also present the HPE storage portfolio from a container integration perspectivce.

Full abstract: "As containers are making their way into the Enterprise they’ve moved from the stateless edge webservers into stateful transactional databases. Being able to provide high performance and highly available persistent storage with advanced data services is essential for any modern deployment of container technology. Learn how Nimble, 3PAR and Cloud Volumes integrate into upstream container ecosystems with end-to-end HPE solutions, including Docker, Kubernetes, Mesos and vendor-specific distributions of Kubernetes such as Red Hat OpenShift. Both for Hybrid and Public Cloud. Understand how HPE Storage differentiated portfolio contributes to important DevOps use cases such as CI/CD pipelines, CaaS, Lift & Transform and many more."

Should be fun. Are you going? Grab a datamattsson.io sticker!

[datamattsson]

Fun project last weekend. Added a battery pack to my genuine #HPENimbleStorage bezel. Might add a battery eliminator option to it as well. It looks pretty damn nice lit up on my desk. Don’t mind my neighbor Totoro.

[datamattsson]

I just passed my three year mark at #HPENimbleStorage. I was pleasantly surprised to find this plaque on my desk this morning. Here's for the future at #HPE 🥂

[datamattsson]

Great fun at the ribbon-cutting event! #HPEDiscover #HPENimbleStorage #dHCI