前言

本次的目的是通过使用k8s搭建一个三节点的zookeeper集群，因为zookeeper集群需要用到存储，所以我们需要准备三个持久卷(Persistent Volume) 简称就是PV。

创建zk-pv

首先通过nfs创建三个共享目录

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

分别对应三节点zk集群中的三个pod的持久化目录，创建好目录之后编写yaml创建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

---

使用如下命令创建zk-pk

kubectl create -f zk-pv.yaml

出现如下提示就代表创建成功

image-20200726131146771

这是我们可以通过如下命令去查看创建成功的pv

kubectl get pv -o wide

image-20200726131248218

创建ZK集群

我们选择使用statefulset去部署zk集群的三节点,并且使用刚刚创建的pv作为存储设备。

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

可以通过kubect get pods -n tool

image-20200726132035822

可以查看到三个pod都是running状态了，我们再看service状态 可以通过kubect get svc -n tool

image-20200726132141885

可以看到我们将2181端口通过nodePort映射给了21811暴露出去了。

验证Zk集群是否启动成功

我们可以通过kubectl exec -it zk-1 -n tools /bin/sh 进入容器

image-20200726132515135

说明当前节点的ZK是一个follower节点

也可以通过以下命令直接查看所有zk节点的状态 for i in 0 1 2; do kubectl exec zk-$i -n tools zkServer.sh status; done

image-20200726132634789

两个follower节点一个leader 代表我们zk集群部署成功！！！