連續(xù)花了兩天時間在搭建Zookeeper集群這件事上了宛瞄，碰到了N多坑，終于是搭建成功了。

準(zhǔn)備工作

1. Zookeeper鏡像苛坚，經(jīng)過我的測試，在Kubernetes上搭建Zookeeper需要用Kubernetes-Zookeeper這個鏡像色难，而不是用官方的Zookeeper鏡像（后面有時間再試一試）泼舱，Kubernetes-Zookeeper這個鏡像在國內(nèi)不好拿，我是采用docker hub構(gòu)建出來的枷莉，Dockerfile如下：

FROM k8s.gcr.io/kubernetes-zookeeper:1.0-3.4.10
MAINTAINER leo.lee <lis85@163.com>

當(dāng)然你也可以直接拉取我構(gòu)建成功的鏡像

docker pull leolee32/kubernetes-library:kubernetes-zookeeper1.0-3.4.10

2. Zookeeper集群需要用到存儲娇昙，這里需要準(zhǔn)備持久卷（PersistentVolume，簡稱PV）笤妙，我這里以yaml文件創(chuàng)建3個PV冒掌，供待會兒3個Zookeeper節(jié)點創(chuàng)建出來的持久卷聲明（PersistentVolumeClaim，簡稱PVC）綁定蹲盘。

persistent-volume.yaml

kind: PersistentVolume
apiVersion: v1
metadata:
  name: k8s-pv-zk1
  annotations:
    volume.beta.kubernetes.io/storage-class: "anything"
  labels:
    type: local
spec:
  capacity:
    storage: 3Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/var/lib/zookeeper"
  persistentVolumeReclaimPolicy: Recycle
---
kind: PersistentVolume
apiVersion: v1
metadata:
  name: k8s-pv-zk2
  annotations:
    volume.beta.kubernetes.io/storage-class: "anything"
  labels:
    type: local
spec:
  capacity:
    storage: 3Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/var/lib/zookeeper"
  persistentVolumeReclaimPolicy: Recycle
---
kind: PersistentVolume
apiVersion: v1
metadata:
  name: k8s-pv-zk3
  annotations:
    volume.beta.kubernetes.io/storage-class: "anything"
  labels:
    type: local
spec:
  capacity:
    storage: 3Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/var/lib/zookeeper"
  persistentVolumeReclaimPolicy: Recycle

使用如下命令創(chuàng)建

kubectl create -f persistent-volume.yaml

create PV

查看PV

kubectl get pv -o wide

查看PV

部署Zookeeper集群

zookeeper.yaml

apiVersion: v1
kind: Service
metadata:
  name: zk-hs
  labels:
    app: zk
spec:
  ports:
  - port: 2888
    name: server
  - port: 3888
    name: leader-election
  clusterIP: None
  selector:
    app: zk
---
apiVersion: v1
kind: Service
metadata:
  name: zk-cs
  labels:
    app: zk
spec:
  ports:
  - port: 2181
    name: client
  selector:
    app: zk
---
apiVersion: policy/v1beta1
kind: PodDisruptionBudget
metadata:
  name: zk-pdb
spec:
  selector:
    matchLabels:
      app: zk
  maxUnavailable: 1
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: zk
spec:
  selector:
    matchLabels:
      app: zk
  serviceName: zk-hs
  replicas: 3
  updateStrategy:
    type: RollingUpdate
  podManagementPolicy: Parallel
  template:
    metadata:
      labels:
        app: zk
    spec:
      affinity:
        podAntiAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            - labelSelector:
                matchExpressions:
                  - key: "app"
                    operator: In
                    values:
                    - zk
              topologyKey: "kubernetes.io/hostname"
      containers:
      - name: kubernetes-zookeeper
        imagePullPolicy: Always
        image: "192.168.242.132/library/kubernetes-zookeeper:1.0-3.4.10"
        resources:
          requests:
            memory: "1Gi"
            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
      securityContext:
        runAsUser: 1000
        fsGroup: 1000
  volumeClaimTemplates:
  - metadata:
      name: datadir
      annotations:
        volume.beta.kubernetes.io/storage-class: "anything"
    spec:
      accessModes: [ "ReadWriteOnce" ]
      resources:
        requests:
          storage: 3Gi

使用如下命令創(chuàng)建

kubectl create -f zookeeper.yaml

創(chuàng)建Zookeeper集群

創(chuàng)建完后會出現(xiàn)一個問題股毫，就是所有的Zookeeper pod都啟動不起來，查看日志發(fā)現(xiàn)是用戶對文件夾【/var/lib/zookeeper】沒有權(quán)限引起的召衔，文件夾的權(quán)限是root用戶铃诬。

image.png

這里如何通過安裝解決還有待研究，目前可以先手動把文件夾【/var/lib/zookeeper】的權(quán)限修改為普通用戶苍凛，Zookeeper pod就可以正常啟動了趣席。
通過命令查看pod

kubectl get pod -o wide

pods

查看PV，發(fā)現(xiàn)持久卷聲明已經(jīng)綁定上了醇蝴。

kubectl get pv -o wide

PV

查看PVC

kubectl get pvc -o wide

pvc

最后來驗證Zookeeper集群是否正常宣肚，查看集群節(jié)點狀態(tài)

for i in 0 1 2; do kubectl exec zk-$i zkServer.sh status; done

zookeeper status

一個leader，兩個follower悠栓，成功Ｃ拐恰！闸迷！