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k8s部署新版本NFS Provisioner

 ·   ·  ☕ 5 分钟  ·  ✍ ayunw

背景

NFS在k8s中作为volume存储已经没有什么新奇的了,这个是最简单也是最容易上手的一种文件存储。最近有一个需求需要在k8s中使用NFS存储,于是记录如下,并且还存在一些骚操作和过程中遇到的坑点,同时记录如下。

访问nfs provisioner的GitHub仓库会发现他提示你该仓库已经被个人归档并且状态已经是只读了。

老的NFS仓库地址

https://github.com/kubernetes-retired/external-storage/tree/master/nfs-client

下面Deprecated表示仓库已经移动到了另外一个GitHub地址了,也就是说他这个仓库已经不在更新了,持续更新的仓库是Moved to 后面指定的仓库了。

新仓库地址:

https://github.com/lorenzofaresin/nfs-subdir-external-provisioner

发现更新的仓库中相比老仓库多了一个功能:添加了一个参数pathPattern,实际上也就是通过设置这个参数可以配置PV的子目录。

nfs-client-provisioner部署

带着好奇心我们来部署一下新的NFS,以下yaml配置文件可以在项目中的deploy目录中找到。我这里的配置根据我的环境稍微做了更改,比如NFS的服务的IP地址。你们根据实际情况修改成自己的nfs服务器地址和path路径。

本次实践在k8s 1.19.0上

class.yaml

$ cat class.yaml
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: managed-nfs-storage
provisioner: k8s-sigs.io/nfs-subdir-external-provisioner # or choose another name, must match deployment's env PROVISIONER_NAME'
parameters:
  archiveOnDelete: "false"

deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nfs-client-provisioner
  labels:
    app: nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: kube-system
spec:
  replicas: 1
  strategy:
    type: Recreate
  selector:
    matchLabels:
      app: nfs-client-provisioner
  template:
    metadata:
      labels:
        app: nfs-client-provisioner
    spec:
      serviceAccountName: nfs-client-provisioner
      containers:
        - name: nfs-client-provisioner
          image: k8s.gcr.io/sig-storage/nfs-subdir-external-provisioner:v4.0.2
          volumeMounts:
            - name: nfs-client-root
              mountPath: /persistentvolumes
          env:
            - name: PROVISIONER_NAME
              value: k8s-sigs.io/nfs-subdir-external-provisioner
            - name: NFS_SERVER
              value: 172.16.33.4
            - name: NFS_PATH
              value: /
      volumes:
        - name: nfs-client-root
          nfs:
            server: 172.16.33.4
            path: /

rbac.yaml

apiVersion: v1
kind: ServiceAccount
metadata:
  name: nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: kube-system
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: nfs-client-provisioner-runner
rules:
  - apiGroups: [""]
    resources: ["nodes"]
    verbs: ["get", "list", "watch"]
  - apiGroups: [""]
    resources: ["persistentvolumes"]
    verbs: ["get", "list", "watch", "create", "delete"]
  - apiGroups: [""]
    resources: ["persistentvolumeclaims"]
    verbs: ["get", "list", "watch", "update"]
  - apiGroups: ["storage.k8s.io"]
    resources: ["storageclasses"]
    verbs: ["get", "list", "watch"]
  - apiGroups: [""]
    resources: ["events"]
    verbs: ["create", "update", "patch"]
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: run-nfs-client-provisioner
subjects:
  - kind: ServiceAccount
    name: nfs-client-provisioner
    # replace with namespace where provisioner is deployed
    namespace: kube-system
roleRef:
  kind: ClusterRole
  name: nfs-client-provisioner-runner
  apiGroup: rbac.authorization.k8s.io
---
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: leader-locking-nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: kube-system
rules:
  - apiGroups: [""]
    resources: ["endpoints"]
    verbs: ["get", "list", "watch", "create", "update", "patch"]
---
kind: RoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: leader-locking-nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: kube-system
subjects:
  - kind: ServiceAccount
    name: nfs-client-provisioner
    # replace with namespace where provisioner is deployed
    namespace: kube-system
roleRef:
  kind: Role
  name: leader-locking-nfs-client-provisioner
  apiGroup: rbac.authorization.k8s.io

注意:

  • 镜像无法拉取的话可以从国外机器拉取镜像然后再导入
  • rbac基本无需更改,配置子目录的时候需要更改class.yaml文件,后面会说

创建所有资源文件

kubectl apply -f class.yaml -f deployment.yaml -f rbac.yaml

通过一个简单的例子来创建pvc

$ cat test-pvc-2.yaml
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: test-pvc-2
  namespace: nacos
spec:
  storageClassName: "managed-nfs-storage"
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 10Gi

$ cat test-nacos-pod-2.yaml
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: nacos-c1-sit-tmp-1
  labels:
    appEnv: sit
    appName: nacos-c1-sit-tmp-1
  namespace: nacos
spec:
  serviceName: nacos-c1-sit-tmp-1
  replicas: 3
  selector:
    matchLabels:
      appEnv: sit
      appName: nacos-c1-sit-tmp-1
  template:
    metadata:
      labels:
        appEnv: sit
        appName: nacos-c1-sit-tmp-1
    spec:
      dnsPolicy: ClusterFirst
      containers:
      - name: nacos
        image: www.ayunw.cn/library/nacos/nacos-server:1.4.1
        ports:
        - containerPort: 8848
        env:
        - name: NACOS_REPLICAS
          value: "1"
        - name: MYSQL_SERVICE_HOST
          value: mysql.ayunw.cn
        - name: MYSQL_SERVICE_DB_NAME
          value: nacos_c1_sit
        - name: MYSQL_SERVICE_PORT
          value: "3306"
        - name: MYSQL_SERVICE_USER
          value: nacos
        - name: MYSQL_SERVICE_PASSWORD
          value: xxxxxxxxx
        - name: MODE
          value: cluster
        - name: NACOS_SERVER_PORT
          value: "8848"
        - name: PREFER_HOST_MODE
          value: hostname
        - name: SPRING_DATASOURCE_PLATFORM
          value: mysql
        - name: TOMCAT_ACCESSLOG_ENABLED
          value: "true"
        - name: NACOS_AUTH_ENABLE
          value: "true"
        - name: NACOS_SERVERS
          value: nacos-c1-sit-0.nacos-c1-sit-tmp-1.nacos.svc.cluster.local:8848 nacos-c1-sit-1.nacos-c1-sit-tmp-1.nacos.svc.cluster.local:8848 nacos-c1-sit-2.nacos-c1-sit-tmp-1.nacos.svc.cluster.local:8848
        imagePullPolicy: IfNotPresent
        resources:
          limits:
            cpu: 500m
            memory: 5Gi
          requests:
            cpu: 100m
            memory: 512Mi
        volumeMounts:
        - name: data
          mountPath: /home/nacos/plugins/peer-finder
          subPath: peer-finder
        - name: data
          mountPath: /home/nacos/data
          subPath: data
  volumeClaimTemplates:
    - metadata:
        name: data
      spec:
        storageClassName: "managed-nfs-storage"
        accessModes:
          - "ReadWriteMany"
        resources:
          requests:
            storage: 10Gi

查看pvc以及nfs存储中的数据

# ll
total 12
drwxr-xr-x 4 root root 4096 Aug  3 13:30 nacos-data-nacos-c1-sit-tmp-1-0-pvc-90d74547-0c71-4799-9b1c-58d80da51973
drwxr-xr-x 4 root root 4096 Aug  3 13:30 nacos-data-nacos-c1-sit-tmp-1-1-pvc-18b3e220-d7e5-4129-89c4-159d9d9f243b
drwxr-xr-x 4 root root 4096 Aug  3 13:31 nacos-data-nacos-c1-sit-tmp-1-2-pvc-26737f88-35cd-42dc-87b6-3b3c78d823da

# ll nacos-data-nacos-c1-sit-tmp-1-0-pvc-90d74547-0c71-4799-9b1c-58d80da51973
total 8
drwxr-xr-x 2 root root 4096 Aug  3 13:30 data
drwxr-xr-x 2 root root 4096 Aug  3 13:30 peer-finder

可以发现手动创建了一个PVC,并且创建一个nacos的deployment使用这个PVC后已经自动创建出相应的PV并且与之绑定,且挂载了数据。

配置子目录

删除之前创建的class.yaml,添加pathPattern参数,然后重新生成sc

$ kubectl delete -f class.yaml

$ vi class.yaml
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: managed-nfs-storage
provisioner: k8s-sigs.io/nfs-subdir-external-provisioner # or choose another name, must match deployment's env PROVISIONER_NAME'
parameters:
  archiveOnDelete: "false"
  # 添加以下参数
  pathPattern: "${.PVC.namespace}/${.PVC.annotations.nfs.io/storage-path}"

创建pvc来测试生成的PV目录是否生成了子目录

$ cat test-pvc.yaml
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: test-pvc-2
  namespace: nacos
  annotations:
    nfs.io/storage-path: "test-path-two" # not required, depending on whether this annotation was shown in the storage class description
spec:
  storageClassName: "managed-nfs-storage"
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 100Mi

创建资源

kubectl apply -f class.yaml -f test-pvc.yaml

查看结果

# pwd
/data/nfs# ll nacos/
total 4
drwxr-xr-x 2 root root 4096 Aug  3 10:21 nacos-pvc-c1-pro

# tree -L 2 .
.
└── nacos
    └── nacos-pvc-c1-pro
2 directories, 0 files

在mount了nfs的机器上查看生成的目录,发现子目录的确已经生成,并且子目录的层级是以"命名空间/注解名称"为规则的。刚好符合了上面StorageClass中定义的pathPattern规则。

provisioner高可用

生产环境中应该尽可能的避免单点故障,因此此处考虑provisioner的高可用架构
更新后的provisioner配置如下:

$ cat nfs-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nfs-client-provisioner
  labels:
    app: nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: kube-system
spec:
  # 因为要实现高可用,所以配置3个pod副本
  replicas: 3
  strategy:
    type: Recreate
  selector:
    matchLabels:
      app: nfs-client-provisioner
  template:
    metadata:
      labels:
        app: nfs-client-provisioner
    spec:
      serviceAccountName: nfs-client-provisioner
      imagePullSecrets:
        - name: registry-auth-paas
      containers:
        - name: nfs-client-provisioner
          image: www.ayunw.cn/nfs-subdir-external-provisioner:v4.0.2-31-gcb203b4
          imagePullPolicy: IfNotPresent
          volumeMounts:
            - name: nfs-client-root
              mountPath: /persistentvolumes
          env:
            - name: PROVISIONER_NAME
              value: k8s-sigs.io/nfs-subdir-external-provisioner
              # 设置高可用允许选举
            - name: ENABLE_LEADER_ELECTION
              value: "True"
            - name: NFS_SERVER
              value: 172.16.33.4
            - name: NFS_PATH
              value: /
      volumes:
        - name: nfs-client-root
          nfs:
            server: 172.16.33.4
            path: /

重建资源

kubectl delete -f nfs-class.yaml -f nfs-deployment.yaml
kubectl apply -f nfs-class.yaml -f nfs-deployment.yaml

查看provisioner高可用是否生效

# kubectl get po -n kube-system | grep nfs
nfs-client-provisioner-666df4d979-fdl8l    1/1     Running   0          20s
nfs-client-provisioner-666df4d979-n54ps    1/1     Running   0          20s
nfs-client-provisioner-666df4d979-s4cql    1/1     Running   0          20s
# kubectl logs -f --tail=20 nfs-client-provisioner-666df4d979-fdl8l -n kube-system
I0803 06:04:41.406441       1 leaderelection.go:242] attempting to acquire leader lease  kube-system/nfs-provisioner-baiducfs...
^C
# kubectl logs -f --tail=20  -n kube-system nfs-client-provisioner-666df4d979-n54ps
I0803 06:04:41.961617       1 leaderelection.go:242] attempting to acquire leader lease  kube-system/nfs-provisioner-baiducfs...
^C
[root@qing-core-kube-master-srv1 nfs-storage]# kubectl logs -f --tail=20  -n kube-system nfs-client-provisioner-666df4d979-s4cql
I0803 06:04:39.574258       1 leaderelection.go:242] attempting to acquire leader lease  kube-system/nfs-provisioner-baiducfs...
I0803 06:04:39.593388       1 leaderelection.go:252] successfully acquired lease kube-system/nfs-provisioner-baiducfs
I0803 06:04:39.593519       1 event.go:278] Event(v1.ObjectReference{Kind:"Endpoints", Namespace:"kube-system", Name:"nfs-provisioner-baiducfs", UID:"3d5cdef6-57da-445e-bcd4-b82d0181fee4", APIVersion:"v1", ResourceVersion:"1471379708", FieldPath:""}): type: 'Normal' reason: 'LeaderElection' nfs-client-provisioner-666df4d979-s4cql_590ac6eb-ccfd-4653-9de5-57015f820b84 became leader
I0803 06:04:39.593559       1 controller.go:820] Starting provisioner controller nfs-provisioner-baiducfs_nfs-client-provisioner-666df4d979-s4cql_590ac6eb-ccfd-4653-9de5-57015f820b84!
I0803 06:04:39.694505       1 controller.go:869] Started provisioner controller nfs-provisioner-baiducfs_nfs-client-provisioner-666df4d979-s4cql_590ac6eb-ccfd-4653-9de5-57015f820b84!

通过successfully acquired lease kube-system/nfs-provisioner-baiducfs可以看到第三个pod成功被选举为leader节点了,高可用生效。

报错

在操作过程中遇到describe pod发现报错如下

Mounting arguments: --description=Kubernetes transient mount for /data/kubernetes/kubelet/pods/2ca70aa9-433c-4d10-8f87-154ec9569504/volumes/kubernetes.io~nfs/nfs-client-root --scope -- mount -t nfs 172.16.41.7:/data/nfs_storage /data/kubernetes/kubelet/pods/2ca70aa9-433c-4d10-8f87-154ec9569504/volumes/kubernetes.io~nfs/nfs-client-root
Output: Running scope as unit: run-rdcc7cfa6560845969628fc551606e69d.scope
mount: /data/kubernetes/kubelet/pods/2ca70aa9-433c-4d10-8f87-154ec9569504/volumes/kubernetes.io~nfs/nfs-client-root: bad option; for several filesystems (e.g. nfs, cifs) you might need a /sbin/mount.<type> helper program.
  Warning  FailedMount  10s  kubelet, node1.ayunw.cn  MountVolume.SetUp failed for volume "nfs-client-root" : mount failed: exit status 32
Mounting command: systemd-run

解决方式:
经排查原因是pod被调度到的节点上没有安装nfs客户端,只需要安装一下nfs客户端nfs-utils即可。

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ayunw
尼古丁的绑架没有救赎,我们皆是上瘾的囚徒


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