开源软件名称：

disk-snapshot

开源软件地址：

https://gitee.com/AliyunContainerService/disk-snapshot

开源软件介绍：

Alibaba Cloud Disk Snapshot Plugin

Overview

An Disk snapshot plugin is available to help simplify storage management.Once user creates VolumeSnapshot with the reference to a snapshot class, snapshot andcorresponding VolumeSnapshotContent object gets dynamically created and becomes ready to be used byworkloads.

This implementation does not depend on CSI feature, but use the csi-snapshot designs which will be used as Alpha feature in k8s 1.13.

Disk Snapshot Plugin will create 3 crds as below.

volumesnapshotclasses.snapshot.storage.k8s.io:  define details to create volumesnapshotcontents, like: storageclass;volumesnapshotcontents.snapshot.storage.k8s.io: define one disk snapshot with the backend, like: pv;volumesnapshots.snapshot.storage.k8s.io:        the claim of one snapshot, like: pvc;

Requirements

Disk Snapshot plugin depends on external-snapshotter (registry.cn-hangzhou.aliyuncs.com/plugins/external-snapshotter:snapshot).
PVC Datasource feature depends on lastest Disk-Controller (registry-vpc.cn-shenzhen.aliyuncs.com/acs/alicloud-disk-controller:v1.11.2.8-ffc6b5b-aliyun).
Secret object with the authentication key for Disk
Service Accounts with required RBAC permissions

Feature Status

Alpha

Compiling and Package

disk-snapshot can be compiled in a form of a container.

To build a container:

$ cd build && sh build.sh

Deploy

Get Kubernetes cluster

You can create a Kubernetes Cluster on Alibaba cloud Container Service

Kubernetes should be 1.12 or after.

Config api-server、controller manager、scheduler compnents

Edit files as below:

/etc/kubernetes/manifests/kube-apiserver.yaml/etc/kubernetes/manifests/kube-controller-manager.yaml/etc/kubernetes/manifests/kube-scheduler.yamlAdd: - --feature-gates=CSINodeInfo=true,CSIDriverRegistry=true,VolumeSnapshotDataSource=true

Notes：
cp /etc/kubernetes/manifests/kube-apiserver.yaml /tmp/kube-apiserver.yaml
edit /tmp/kube-apiserver.yaml
cp /tmp/kube-apiserver.yaml /etc/kubernetes/manifests/kube-apiserver.yaml

Config Kubelet

# vi /etc/systemd/system/kubelet.service.d/10-kubeadm.confAdd:Environment="KUBELET_FEATURE_GATES_ARGS=--feature-gates=CSINodeInfo=true,CSIDriverRegistry=true,VolumeSnapshotDataSource=true"

restart kubelet:

systemctl daemon-reload && service kubelet restart

Deploy Snapshot Controller

If the cluster not in STS mode, you need to config AK info to plugin; Set ACCESS_KEY_ID, ACCESS_KEY_SECRET to environment;

# kubectl create -f ./deploy/snapshot-controller.yaml# kubectl get pod -n kube-system | grep alicloud-disk-snapshotalicloud-disk-snapshot-89c88c7f7-6z95j                       2/2     Running   0          42s

Deploy SnapshotClass

# kubectl create -f ./deploy/snapshotclass.yaml# kubectl get volumesnapshotclasses.snapshot.storage.k8s.ioNAME                AGEdefault-snapclass   15s

3 CRDs be created：

# kubectl get crd | grep snapvolumesnapshotclasses.snapshot.storage.k8s.io    2019-01-16T12:00:46Zvolumesnapshotcontents.snapshot.storage.k8s.io   2019-01-16T12:00:46Zvolumesnapshots.snapshot.storage.k8s.io          2019-01-16T12:00:46Z

Usage

Create Pod with Disk

Create a deployment and pvc, using disk volume.

# kubectl create -f ./deploy/deploy-origin.yaml# kubectl get podNAME                              READY   STATUS    RESTARTS   AGEdynamic-create-7fbf55b58f-qnrgm   1/1     Running   0          21s# kubectl get pvcNAME       STATUS   VOLUME                   CAPACITY   ACCESS MODES   STORAGECLASS        AGEpvc-disk   Bound    d-wz9hhnhxu66zs6r6yyyq   20Gi       RWO            alicloud-disk-ssd   25s# kubectl exec -ti dynamic-create-7fbf55b58f-qnrgm touch /data/snapshot123

Step 4: Create Snapshot with Pvc

# kubectl create -f snapshot.yamlvolumesnapshot.snapshot.storage.k8s.io/snapshot-test created# kubectl get volumesnapshots.snapshot.storage.k8s.ioNAME            AGEsnapshot-test   2m# kubectl get volumesnapshotcontents.snapshot.storage.k8s.ioNAME                                               AGEsnapcontent-77a75b63-1987-11e9-a520-00163e024341   2m

snapshot.yaml define the data source pvc name, and snapshotClass name.

Create Pvc with Snapshot

# kubectl create -f deploy-datasource.yaml# kubectl get podNAME                               READY   STATUS    RESTARTS   AGEdynamic-create-7fbf55b58f-qnrgm    1/1     Running   0          10mdynamic-snapshot-fdc86b6d8-bl6h5   1/1     Running   0          13s# kubectl get pvcNAME            STATUS   VOLUME                   CAPACITY   ACCESS MODES   STORAGECLASS        AGEdisk-snapshot   Bound    d-wz98cj3vphycosrm6joa   20Gi       RWO            alicloud-disk-ssd   4spvc-disk        Bound    d-wz9hhnhxu66zs6r6yyyq   20Gi       RWO            alicloud-disk-ssd   10m# kubectl exec -ti dynamic-snapshot-fdc86b6d8-bl6h5 ls /datalost+found  snapshot123

New pvc create a new disk, which using the snapshot. And the new disk contains old disk file(snapshot123).