Kubernetes中分布式存储Rook-Ceph部署快速演练

最近在项目中有涉及到Kubernetes的分布式存储部分的内容,也抽空多了解了一些。项目主要基于Rook-Ceph运行,考虑到Rook-Ceph部署也不那么简单,官方文档的步骤起点也不算低,因此,在整合官方文档的某些步骤的基础上,写篇文章简单总结一下。

Rook-Ceph是Kubernetes中分布式存储的一种解决方案,Rook作为一种开源的、云原生的存储编排器,为各种存储服务在云原生的环境中实现无缝整合,提供了所必须的平台、框架和服务;而Ceph则是Rook所支持的众多存储方案的一种,在Kubernetes环境里,Ceph基于Rook能够为应用程序提供块存储(Block Storage),对象存储(Object Storage)以及共享文件系统(SFS)服务。此处就不对Rook Ceph进行太多的介绍,直接步入正题,一步一步地演练Rook-Ceph从安装部署到使用的整个过程。

注意:本文所有的yaml文件都是为了配合整个演练过程而设计的,理论上不能直接用在生产环境。如有需要,在用在生产环境之前,请确保所需的参数都已正确配置。

安装Kubernetes

安装Kubernetes。安装方法有很多,不怕麻烦可以徒手安装,也可以直接使用云供应商的托管服务,比如Azure AKS,也可以使用Rancher RKE,在此就不赘述了。

安装Rook Ceph Operator

这里我们基于Ceph来讨论。事实上Rook支持Ceph、Cassandra、CockroachDB、EdgeFS、NFS以及YugabyteDB等多种存储供应商(Storage Provider),针对不同的存储供应商,Rook提供不同的Operator来进行资源的部署和管理。使用下面的命令来安装Rook Ceph Operator:

helm repo add rook-release https://charts.rook.io/release
kubectl create namespace rook-ceph
helm install --namespace rook-ceph rook-ceph rook-release/rook-ceph

安装Ceph集群(Ceph Cluster)

可以使用下面的yaml文件:

# ceph-cluster-deploy.yaml
apiVersion: ceph.rook.io/v1
kind: CephCluster
metadata:
  name: rook-ceph
  namespace: rook-ceph
spec:
  cephVersion:
    image: ceph/ceph:v15.2.7
    allowUnsupported: false
  dataDirHostPath: /var/lib/rook
  skipUpgradeChecks: false
  continueUpgradeAfterChecksEvenIfNotHealthy: false
  mon:
    count: 3
    allowMultiplePerNode: false
  mgr:
    modules:
    - name: pg_autoscaler
      enabled: true
  dashboard:
    enabled: true
    ssl: true
  monitoring:
    enabled: false
    rulesNamespace: rook-ceph
  network:
  crashCollector:
    disable: false
  cleanupPolicy:
    confirmation: ""
    sanitizeDisks:
      method: quick
      dataSource: zero
      iteration: 1
    allowUninstallWithVolumes: false
  annotations:
  labels:
  resources:
  removeOSDsIfOutAndSafeToRemove: false
    useAllNodes: true
    useAllDevices: false
    deviceFilter: nvme1n1
    config:
      osdsPerDevice: "1"
  disruptionManagement:
    managePodBudgets: false
    osdMaintenanceTimeout: 30
    pgHealthCheckTimeout: 0
    manageMachineDisruptionBudgets: false
    machineDisruptionBudgetNamespace: openshift-machine-api
  healthCheck:
    daemonHealth:
      mon:
        disabled: false
        interval: 45s
      osd:
        disabled: false
        interval: 60s
      status:
        disabled: false
        interval: 60s
    livenessProbe:
      mon:
        disabled: false
      mgr:
        disabled: false
      osd:
        disabled: false

然后使用以下命令创建Ceph集群:

kubectl create -f ceph-cluster-deploy.yaml

命令执行成功之后,需要等待几分钟,以便OSD能够成功启动。执行下面的命令可以查看所有容器的状态:

kubectl -n rook-ceph get pod

正常情况下,应该可以看到类似以下的结果:

NAME                                                 READY   STATUS      RESTARTS   AGE
csi-cephfsplugin-provisioner-d77bb49c6-n5tgs         5/5     Running     0          140s
csi-cephfsplugin-provisioner-d77bb49c6-v9rvn         5/5     Running     0          140s
csi-cephfsplugin-rthrp                               3/3     Running     0          140s
csi-rbdplugin-hbsm7                                  3/3     Running     0          140s
csi-rbdplugin-provisioner-5b5cd64fd-nvk6c            6/6     Running     0          140s
csi-rbdplugin-provisioner-5b5cd64fd-q7bxl            6/6     Running     0          140s
rook-ceph-crashcollector-minikube-5b57b7c5d4-hfldl   1/1     Running     0          105s
rook-ceph-mgr-a-64cd7cdf54-j8b5p                     1/1     Running     0          77s
rook-ceph-mon-a-694bb7987d-fp9w7                     1/1     Running     0          105s
rook-ceph-mon-b-856fdd5cb9-5h2qk                     1/1     Running     0          94s
rook-ceph-mon-c-57545897fc-j576h                     1/1     Running     0          85s
rook-ceph-operator-85f5b946bd-s8grz                  1/1     Running     0          92m
rook-ceph-osd-0-6bb747b6c5-lnvb6                     1/1     Running     0          23s
rook-ceph-osd-1-7f67f9646d-44p7v                     1/1     Running     0          24s
rook-ceph-osd-2-6cd4b776ff-v4d68                     1/1     Running     0          25s
rook-ceph-osd-prepare-node1-vx2rz                    0/2     Completed   0          60s
rook-ceph-osd-prepare-node2-ab3fd                    0/2     Completed   0          60s
rook-ceph-osd-prepare-node3-w4xyz                    0/2     Completed   0          60s

需要注意几点:

  • ceph-cluster-deploy.yaml并没有包括所有的Ceph集群创建的参数,可以参考https://rook.io/docs/rook/v1.5/ceph-cluster-crd.html 来了解所有的配置信息
  • 这里的deviceFilter: nvme1n1是用来指定在每个Kubernetes节点上应该使用的卷(Volume)的名称。这个Volume不能格式化成任何文件系统,否则Ceph将不会使用它作为存储卷。我在AWS上创建了独立的EBS卷,然后直接Attach到Kubernetes节点的机器上,通过lsblk命令即可获得卷的名称,将这个名称填入deviceFilter设置即可

安装Rook Toolbox

Rook Toolbox是一个运行在rook-ceph命名空间下的容器,通过它可以执行一些Ceph的管理任务,建议安装,还是挺实用的。创建一个yaml文件:

# rook-toolbox.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: rook-ceph-tools
  namespace: rook-ceph
  labels:
    app: rook-ceph-tools
spec:
  replicas: 1
  selector:
    matchLabels:
      app: rook-ceph-tools
  template:
    metadata:
      labels:
        app: rook-ceph-tools
    spec:
      dnsPolicy: ClusterFirstWithHostNet
      containers:
      - name: rook-ceph-tools
        image: rook/ceph:v1.5.3
        command: ["/tini"]
        args: ["-g", "--", "/usr/local/bin/toolbox.sh"]
        imagePullPolicy: IfNotPresent
        env:
          - name: ROOK_CEPH_USERNAME
            valueFrom:
              secretKeyRef:
                name: rook-ceph-mon
                key: ceph-username
          - name: ROOK_CEPH_SECRET
            valueFrom:
              secretKeyRef:
                name: rook-ceph-mon
                key: ceph-secret
        volumeMounts:
          - mountPath: /etc/ceph
            name: ceph-config
          - name: mon-endpoint-volume
            mountPath: /etc/rook
      volumes:
        - name: mon-endpoint-volume
          configMap:
            name: rook-ceph-mon-endpoints
            items:
            - key: data
              path: mon-endpoints
        - name: ceph-config
          emptyDir: {}
      tolerations:
        - key: "node.kubernetes.io/unreachable"
          operator: "Exists"
          effect: "NoExecute"
          tolerationSeconds: 5

然后:

kubectl create -f rook-toolbox.yaml

接着可以执行下面的命令,进入Rook Toolbox容器:

kubectl -n rook-ceph exec -it deploy/rook-ceph-tools -- bash

然后使用ceph status命令来查看集群的状态。正常的话应该可以看到类似下面的结果:

$ ceph status
  cluster:
    id:     a0452c76-30d9-4c1a-a948-5d8405f19a7c
    health: HEALTH_OK

  services:
    mon: 3 daemons, quorum a,b,c (age 3m)
    mgr: a(active, since 2m)
    osd: 3 osds: 3 up (since 1m), 3 in (since 1m)

一定要确保health的状态为HEALTH_OK,如果不是HEALTH_OK,则需要排查原因并解决。问题排查指南:https://rook.io/docs/rook/v1.5/ceph-common-issues.html。

部署块存储(Provisioning Block Storage)

使用下面的yaml:

# ceph-block-deploy.yaml
apiVersion: ceph.rook.io/v1
kind: CephBlockPool
metadata:
  name: replicapool
  namespace: rook-ceph
spec:
  failureDomain: host
  replicated:
    size: 3

---
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: rook-ceph-block
  annotations:
    storageclass.kubernetes.io/is-default-class: "true"
provisioner: rook-ceph.rbd.csi.ceph.com
parameters:
  clusterID: rook-ceph
  pool: replicapool
  imageFormat: "2"
  imageFeatures: layering
  csi.storage.k8s.io/provisioner-secret-name: rook-csi-rbd-provisioner
  csi.storage.k8s.io/provisioner-secret-namespace: rook-ceph
  csi.storage.k8s.io/controller-expand-secret-name: rook-csi-rbd-provisioner
  csi.storage.k8s.io/controller-expand-secret-namespace: rook-ceph
  csi.storage.k8s.io/node-stage-secret-name: rook-csi-rbd-node
  csi.storage.k8s.io/node-stage-secret-namespace: rook-ceph
  csi.storage.k8s.io/fstype: ext4
reclaimPolicy: Retain

然后:

Kubectl create -f ceph-block-deploy.yaml

在这个yaml中,同时定义了名为rook-ceph-blockStorageClass,用以在pods启动的时候能够动态创建基于Ceph的块存储(通过pool: replicapool的设置指定)。此外,在这个StorageClass中,设定了storageclass.kubernetes.io/is-default-class: "true"。因此,在PersistentVolumeClaim中即使没有指定storageClassName,Kubernetes也会默认使用Ceph块存储来保存app的数据。

部署块存储的详细内容可以参考:https://rook.io/docs/rook/v1.5/ceph-block.html。

部署对象存储(Provisioning Object Storage)

使用下面的yaml:

# ceph-s3-deploy.yaml
apiVersion: ceph.rook.io/v1
kind: CephObjectStore
metadata:
  name: my-store
  namespace: rook-ceph
spec:
  metadataPool:
    failureDomain: host
    replicated:
      size: 3
  dataPool:
    failureDomain: host
    erasureCoded:
      dataChunks: 2
      codingChunks: 1
  preservePoolsOnDelete: true
  gateway:
    type: s3
    sslCertificateRef:
    port: 80
    # securePort: 443
    instances: 3
  healthCheck:
    bucket:
      disabled: false
      interval: 60s

然后:

kubectl create -f ceph-s3-deploy.yaml

等待几分钟后,执行下面的命令:

kubectl -n rook-ceph get pod -l app=rook-ceph-rgw

此时应该可以在pod的列表中看到名字包含有rgw的pod处于Running状态。
接下来就是要在对象存储上创建Bucket。官方提供了基于StorageClass的创建方式。这里介绍另一种方式,就是借用MINIO的管理工具来创建。使用下面的shell脚本:

# setup-s3-storage.sh
#! /bin/bash
echo "Creating Ceph User"
CREATE_USER_OUTPUT=`kubectl -n rook-ceph exec -it $(kubectl -n rook-ceph get pod -l "app=rook-ceph-tools" -o jsonpath='{.items[0].metadata.name}') -- radosgw-admin user create --uid=system-user --display-name=system-user --system`
ACCESS_KEY=$(echo $CREATE_USER_OUTPUT | jq -r ".keys[0].access_key")
SECRET_KEY=$(echo $CREATE_USER_OUTPUT | jq -r ".keys[0].secret_key")
echo "User was created successfully"
echo "S3 ACCESS KEY = $ACCESS_KEY"
echo "S3 SECRET KEY = $SECRET_KEY"

echo "Creating Ceph S3 Bucket"
kubectl -n rook-ceph exec -it $(kubectl -n rook-ceph get pod -l "app=rook-ceph-tools" -o jsonpath='{.items[0].metadata.name}') -- curl https://dl.min.io/client/mc/release/linux-amd64/mc --output mc
kubectl -n rook-ceph exec -it $(kubectl -n rook-ceph get pod -l "app=rook-ceph-tools" -o jsonpath='{.items[0].metadata.name}') -- chmod +x mc
kubectl -n rook-ceph exec -it $(kubectl -n rook-ceph get pod -l "app=rook-ceph-tools" -o jsonpath='{.items[0].metadata.name}') -- ./mc config host add mys3 http://rook-ceph-rgw-signals-store/ "$ACCESS_KEY" "$SECRET_KEY"
kubectl -n rook-ceph exec -it $(kubectl -n rook-ceph get pod -l "app=rook-ceph-tools" -o jsonpath='{.items[0].metadata.name}') -- ./mc mb mys3/data
echo "Ceph S3 Bucket created successfully"
echo "S3 ACCESS KEY = $ACCESS_KEY"
echo "S3 SECRET KEY = $SECRET_KEY"

在确保了当前机器上安装了jq后,执行:

chmod +x setup-s3-storage.sh
./setup-s3-storage.sh

此时会输出S3的Access Key和Secret Key。创建的Bucket名为data。
验证Object Storage是否部署成功,首先执行下面的命令进入Rook Toolbox:

kubectl -n rook-ceph exec -it deploy/rook-ceph-tools -- bash

然后执行:

export AWS_HOST=<host>
export AWS_ENDPOINT=<endpoint>
export AWS_ACCESS_KEY_ID=<accessKey>
export AWS_SECRET_ACCESS_KEY=<secretKey>
  • 为rgw Service的DNS主机名。如果你的Object Storage名为my-store,那么主机名就是rook-ceph-rgw-my-store.rook-ceph
  • 为rgw Service的端点。执行kubectl -n rook-ceph get svc rook-ceph-rgw-my-store,然后将ClusterIP和端口号拼接起来作为endpoint的值
  • accessKey:上一步获得的Access Key
  • secretKey:上一步获得的Secret Key
    以下是一个例子:
export AWS_HOST=rook-ceph-rgw-my-store.rook-ceph
export AWS_ENDPOINT=10.104.35.31:80
export AWS_ACCESS_KEY_ID=XEZDB3UJ6X7HVBE7X7MA
export AWS_SECRET_ACCESS_KEY=7yGIZON7EhFORz0I40BFniML36D2rl8CQQ5kXU6l

接下来,安装一个s3cmd的工具:

yum --assumeyes install s3cmd

然后随便写一些内容到rookObj文件:

echo "Hello Rook" > /tmp/rookObj

然后通过s3cmd,将这个文件保存到S3:

s3cmd put /tmp/rookObj --no-ssl --host=${AWS_HOST} --host-bucket=  s3://data

注意--host-bucket=后的空格。
然后,使用s3cmd从Bucket将文件下载并另存为另一个文件:

s3cmd get s3://data/rookObj /tmp/rookObj-download --no-ssl --host=${AWS_HOST} --host-bucket=

最后,通过cat命令,查看下载下来的文件的内容是否正确:

cat /tmp/rookObj-download

如果能够看到Hello Rook的输出字样,表示一切正常。接下来就可以在app中使用Ceph Block Storage和Ceph Object Storage了。

部署对象存储的详细内容可以参考:https://rook.io/docs/rook/v1.5/ceph-object.html

下一步

之后我会使用Microsoft .NET 5,编写一个Web API应用程序并部署到Kubernetes环境,演示如何在app中使用本文所部署的Ceph Block Storage和Ceph Object Storage。

posted @ 2021-02-25 20:59  dax.net  阅读(259)  评论(0编辑  收藏