前言

本次的目的是通過使用k8s搭建一個(gè)三節(jié)點(diǎn)的zookeeper集群，因?yàn)?code>zookeeper集群需要用到存儲(chǔ)，所以我們需要準(zhǔn)備三個(gè)持久卷(Persistent Volume) 簡(jiǎn)稱就是PV。

創(chuàng)建zk-pv

首先通過nfs創(chuàng)建三個(gè)共享目錄

mkdir -p /data/share/pv/{zk01,zk02,zk03}

分別對(duì)應(yīng)三節(jié)點(diǎn)zk集群中的三個(gè)pod的持久化目錄，創(chuàng)建好目錄之后編寫yaml創(chuàng)建zk-pv.yaml

apiVersion: v1
kind: PersistentVolume
metadata:
  name: k8s-pv-zk01
  namespace: tools
  labels:
    app: zk
  annotations:
    volume.beta.kubernetes.io/storage-class: "anything"
spec:
  capacity:
    storage: 5Gi
  accessModes:
  - ReadWriteOnce
  hostPath:
    path: /data/share/pv/zk01
  persistentVolumeReclaimPolicy: Recycle
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: k8s-pv-zk02
  namespace: tools
  labels:
    app: zk
  annotations:
    volume.beta.kubernetes.io/storage-class: "anything"
spec:
  capacity:
    storage: 5Gi
  accessModes:
  - ReadWriteOnce
  hostPath:
    path: /data/share/pv/zk02
  persistentVolumeReclaimPolicy: Recycle
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: k8s-pv-zk03
  namespace: tools
  labels:
    app: zk
  annotations:
    volume.beta.kubernetes.io/storage-class: "anything"
spec:
  capacity:
    storage: 5Gi
  accessModes:
  - ReadWriteOnce
  hostPath:
    path: /data/share/pv/zk03
  persistentVolumeReclaimPolicy: Recycle
---

使用如下命令創(chuàng)建zk-pk

kubectl create -f zk-pv.yaml

出現(xiàn)如下提示就代表創(chuàng)建成功

image-20200726131146771

這是我們可以通過如下命令去查看創(chuàng)建成功的pv

kubectl get pv -o wide

image-20200726131248218

創(chuàng)建ZK集群

我們選擇使用statefulset去部署zk集群的三節(jié)點(diǎn),并且使用剛剛創(chuàng)建的pv作為存儲(chǔ)設(shè)備。

zk.yaml

apiVersion: v1
kind: Service
metadata:
  name: zk-hs
  namespace: tools
  labels:
    app: zk
spec:
  selector:
    app: zk
  clusterIP: None
  ports:
  - name: server
    port: 2888
  - name: leader-election
    port: 3888
--- 
apiVersion: v1
kind: Service
metadata:
  name: zk-cs
  namespace: tools
  labels:
    app: zk
spec:
  selector:
    app: zk
  type: NodePort
  ports:
  - name: client
    port: 2181
    nodePort: 21811
---
apiVersion: policy/v1beta1
kind: PodDisruptionBudget
metadata:
  name: zk-pdb
  namespace: tools
spec:
  selector:
    matchLabels:
      app: zk
  maxUnavailable: 1
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: zk
  namespace: tools
spec:
  selector:
    matchLabels:
      app: zk # has to match .spec.template.metadata.labels
  serviceName: "zk-hs"
  replicas: 3 # by default is 1
  updateStrategy:
    type: RollingUpdate
  podManagementPolicy: Parallel
  template:
    metadata:
      labels:
        app: zk # has to match .spec.selector.matchLabels
    spec:
      containers:
      - name: zk
        imagePullPolicy: Always
        image: leolee32/kubernetes-library:kubernetes-zookeeper1.0-3.4.10
        resources:
          requests:
            memory: "500Mi"
            cpu: "0.5"
        ports:
        - containerPort: 2181
          name: client
        - containerPort: 2888
          name: server
        - containerPort: 3888
          name: leader-election
        command:
        - sh
        - -c
        - "start-zookeeper \
        --servers=3 \
        --data_dir=/var/lib/zookeeper/data \
        --data_log_dir=/var/lib/zookeeper/data/log \
        --conf_dir=/opt/zookeeper/conf \
        --client_port=2181 \
        --election_port=3888 \
        --server_port=2888 \
        --tick_time=2000 \
        --init_limit=10 \
        --sync_limit=5 \
        --heap=512M \
        --max_client_cnxns=60 \
        --snap_retain_count=3 \
        --purge_interval=12 \
        --max_session_timeout=40000 \
        --min_session_timeout=4000 \
        --log_level=INFO"
        readinessProbe:
          exec:
            command:
            - sh
            - -c
            - "zookeeper-ready 2181"
          initialDelaySeconds: 10
          timeoutSeconds: 5
        livenessProbe:
          exec:
            command:
            - sh
            - -c
            - "zookeeper-ready 2181"
          initialDelaySeconds: 10
          timeoutSeconds: 5
        volumeMounts:
        - name: datadir
          mountPath: /var/lib/zookeeper
  volumeClaimTemplates:
  - metadata:
      name: datadir
      annotations:
        volume.beta.kubernetes.io/storage-class: "anything"
    spec:
      accessModes: [ "ReadWriteOnce" ]
      resources:
        requests:
          storage: 1Gi

使用kubectl apply -f zk.yaml部署

image-20200726131900366

可以通過kubect get pods -n tool

image-20200726132035822

可以查看到三個(gè)pod都是running狀態(tài)了，我們?cè)倏磗ervice狀態(tài) 可以通過kubect get svc -n tool

image-20200726132141885

可以看到我們將2181端口通過nodePort映射給了21811暴露出去了。

驗(yàn)證Zk集群是否啟動(dòng)成功

我們可以通過kubectl exec -it zk-1 -n tools /bin/sh 進(jìn)入容器

image-20200726132515135

說明當(dāng)前節(jié)點(diǎn)的ZK是一個(gè)follower節(jié)點(diǎn)

也可以通過以下命令直接查看所有zk節(jié)點(diǎn)的狀態(tài) for i in 0 1 2; do kubectl exec zk-$i -n tools zkServer.sh status; done

image-20200726132634789

兩個(gè)follower節(jié)點(diǎn)一個(gè)leader 代表我們zk集群部署成功！??！