CSI 驱动开发

CSI 概述

CSI（Container Storage Interface）是 K8s 与存储插件之间的标准接口，允许第三方存储厂商开发插件而无需修改 K8s 核心代码。

CSI 架构

kubelet
  │ gRPC (CSI)
  ▼
CSI Node Plugin（每个节点运行）
  ├── NodeStageVolume：挂载到节点
  └── NodePublishVolume：挂载到 Pod

CSI Controller Plugin（集中运行）
  ├── CreateVolume：创建存储卷
  ├── DeleteVolume：删除存储卷
  ├── ControllerPublishVolume：将卷附加到节点
  └── CreateSnapshot：创建快照

CSI 接口

// CSI 控制器接口
type ControllerServer interface {
    CreateVolume(ctx context.Context, req *csi.CreateVolumeRequest) (*csi.CreateVolumeResponse, error)
    DeleteVolume(ctx context.Context, req *csi.DeleteVolumeRequest) (*csi.DeleteVolumeResponse, error)
    ControllerPublishVolume(ctx context.Context, req *csi.ControllerPublishVolumeRequest) (*csi.ControllerPublishVolumeResponse, error)
    ControllerUnpublishVolume(ctx context.Context, req *csi.ControllerUnpublishVolumeRequest) (*csi.ControllerUnpublishVolumeResponse, error)
    CreateSnapshot(ctx context.Context, req *csi.CreateSnapshotRequest) (*csi.CreateSnapshotResponse, error)
    DeleteSnapshot(ctx context.Context, req *csi.DeleteSnapshotRequest) (*csi.DeleteSnapshotResponse, error)
    ListVolumes(ctx context.Context, req *csi.ListVolumesRequest) (*csi.ListVolumesResponse, error)
    GetCapacity(ctx context.Context, req *csi.GetCapacityRequest) (*csi.GetCapacityResponse, error)
    ControllerGetCapabilities(ctx context.Context, req *csi.ControllerGetCapabilitiesRequest) (*csi.ControllerGetCapabilitiesResponse, error)
    ValidateVolumeCapabilities(ctx context.Context, req *csi.ValidateVolumeCapabilitiesRequest) (*csi.ValidateVolumeCapabilitiesResponse, error)
}

// CSI 节点接口
type NodeServer interface {
    NodeStageVolume(ctx context.Context, req *csi.NodeStageVolumeRequest) (*csi.NodeStageVolumeResponse, error)
    NodeUnstageVolume(ctx context.Context, req *csi.NodeUnstageVolumeRequest) (*csi.NodeUnstageVolumeResponse, error)
    NodePublishVolume(ctx context.Context, req *csi.NodePublishVolumeRequest) (*csi.NodePublishVolumeResponse, error)
    NodeUnpublishVolume(ctx context.Context, req *csi.NodeUnpublishVolumeRequest) (*csi.NodeUnpublishVolumeResponse, error)
    NodeGetInfo(ctx context.Context, req *csi.NodeGetInfoRequest) (*csi.NodeGetInfoResponse, error)
    NodeGetCapabilities(ctx context.Context, req *csi.NodeGetCapabilitiesRequest) (*csi.NodeGetCapabilitiesResponse, error)
}

主流 CSI 驱动

# AWS EBS CSI
helm repo add aws-ebs-csi-driver https://kubernetes-sigs.github.io/aws-ebs-csi-driver
helm install aws-ebs-csi-driver aws-ebs-csi-driver/aws-ebs-csi-driver \
  --namespace kube-system

# NFS CSI
helm repo add csi-driver-nfs https://raw.githubusercontent.com/kubernetes-csi/csi-driver-nfs/master/charts
helm install csi-driver-nfs csi-driver-nfs/csi-driver-nfs \
  --namespace kube-system

# Local Path Provisioner（开发环境）
kubectl apply -f https://raw.githubusercontent.com/rancher/local-path-provisioner/master/deploy/local-path-storage.yaml

StorageClass 配置

# AWS EBS gp3
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: ebs-gp3
provisioner: ebs.csi.aws.com
parameters:
  type: gp3
  iops: "3000"
  throughput: "125"
  encrypted: "true"
  kmsKeyId: arn:aws:kms:us-east-1:123456789:key/xxx
reclaimPolicy: Delete
allowVolumeExpansion: true
volumeBindingMode: WaitForFirstConsumer