技術標籤：k8s selector

前言

最近在工作上調研k8s部署kafka叢集的方案，順帶調研部署zookeeper方案。以下配置和部署方案都是親測可用，有問題可以評論或私我解決。

kafka需要依賴zookeeper

kafka的生產者與消費者需要在zookeeper中註冊，不然消費者怎麼知道生產者是否存活之類的哈哈。廢話不多說，直接上乾貨！

本文用的是statefulset和動態儲存部署zookeeper和kafka叢集。

部署zookeeper

apiVersion: v1
kind: Service
metadata:
  name: zk-headless
  namespace: liulei
  labels:
    app: zk
spec:
  ports:
  - port: 2888
    name: server
  - port: 3888
    name: leader-election
  clusterIP: None   #指定無頭服務，需要對外暴露自行建立一個service
  selector:
    app: zk
---
apiVersion: policy/v1beta1
kind: PodDisruptionBudget
metadata:
  name: zk-pdb
  namespace: liulei
spec:
  selector:
    matchLabels:
      app: zk
  minAvailable: 2
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: zk     #指定的zookeeper名稱會在kafka.yaml裡面用來配置和kafka連線，會建立pod為zk-0,zk-1,zk-2......這裡只建立了三個
  namespace: liulei
spec:
  selector:
    matchLabels:
      app: zk
  serviceName: zk-headless
  replicas: 3
  updateStrategy:
    type: RollingUpdate # K8s 會將 StatefulSet 管理的 pod 分批次逐步替換掉
  podManagementPolicy: OrderedReady # 設定為Parallel這樣Pod的建立就不必等待，而是會同時建立、同時刪除
  template:
    metadata:
      labels:
        app: zk
    spec:
      containers:
      - name: k8s-zk
        image: k8szk:1.0-3.4.10   #需要指定自己的映象，可去阿里雲上下載zookeeper映象
        imagePullPolicy: Always
        resources:
          requests:
            memory: "1Gi"
            cpu: "1000m"
          limits:
            memory: "1Gi"
            cpu: "1000m"
        ports:
        - containerPort: 2181
          name: client
        - containerPort: 2888
          name: server
        - containerPort: 3888
          name: leader-election
        command:
        - sh
        - -c
        - "start-zookeeper 
          --servers=5 
          --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"
        - "zkGenConfig.sh && exec zkServer.sh start-foreground"
        readinessProbe:
          exec:
            command:
            - sh
            - -c
            - "zookeeper-ready 2181"
          initialDelaySeconds: 10
          timeoutSeconds: 5
        livenessProbe:
          exec:
            command:
            - sh
            - -c
            - "zookeeper-ready 2181"
          initialDelaySeconds: 10
          timeoutSeconds: 5
        imagePullPolicy: IfNotPresent
        volumeMounts:
        - name: zookeeper-pvc
          mountPath: /var/lib/zookeeper
      securityContext:
        runAsUser: 1000
        fsGroup: 1000
  volumeClaimTemplates:
  - metadata:
      name: zookeeper-pvc
      labels:
        type: stateful
    spec:
      accessModes: [ "ReadWriteMany" ]
      storageClassName: storageclass-default   #需要指定你自己的動態儲存類名
      resources:
        requests:
          storage: 1Gi
 

驗證部署zookeeper

待zookeeper叢集建立成功後驗證zookeeper叢集（注意修改自己的名稱空間 -n後面引數）：

[[email protected] liulei]# for i in 0 1 2; do kubectl exec zk-$i -n liulei -- hostname; done

zk-0

zk-1

zk-2

[[email protected] liulei]# for i in 0 1 2; do echo "myid zk-$i";kubectl exec zk-$i -nliulei -- cat /var/lib/zookeeper/data/myid; done
 

myid zk-0

1

myid zk-1

2

myid zk-2

3

[[email protected] liulei]# for i in 0 1 2; do kubectl exec zk-$i -nliulei -- hostname -f; done

zk-0.zk-headless.liulei.svc.cluster.local

zk-1.zk-headless.liulei.svc.cluster.local

zk-2.zk-headless.liulei.svc.cluster.local

部署kafka

apiVersion: v1
kind: Service
metadata:
  name: kafka-svc
  namespace: liulei
  labels:
    app: kafka
spec:
  ports:
  - port: 9093
    name: server
  clusterIP: None   #建立無頭服務，如果需要對外暴露埠可自行建立service
  selector:
    app: kafka
---
apiVersion: policy/v1beta1
kind: PodDisruptionBudget
metadata:
  name: kafka-pdb
  namespace: liulei
spec:
  selector:
    matchLabels:
      app: kafka
  minAvailable: 2
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: kafka
  namespace: liulei
spec:
  selector:
    matchLabels:
      app: kafka
  serviceName: kafka-svc
  replicas: 3
  template:
    metadata:
      labels:
        app: kafka
    spec:
      affinity:
        podAntiAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            - labelSelector:
                matchExpressions:
                  - key: "app"
                    operator: In
                    values: 
                    - kafka
              topologyKey: "kubernetes.io/hostname"
        podAffinity:
          preferredDuringSchedulingIgnoredDuringExecution:
             - weight: 1
               podAffinityTerm:
                 labelSelector:
                    matchExpressions:
                      - key: "app"
                        operator: In
                        values: 
                        - zk
                 topologyKey: "kubernetes.io/hostname"
      terminationGracePeriodSeconds: 300
      containers:
      - name: k8skafka
        imagePullPolicy: Always
        image: registry.cn-hangzhou.aliyuncs.com/ccgg/k8skafka:v1  #可自行去阿里雲拉去對應映象
        resources:
          requests:
            memory: "1Gi"
            cpu: "1000m"
          limits:
            memory: "1Gi"
            cpu: "1000m"
        ports:
        - containerPort: 9093
          name: server
        command:
        - sh
        - -c
        - "exec kafka-server-start.sh /opt/kafka/config/server.properties --override broker.id=${HOSTNAME##*-}    
          --override listeners=PLAINTEXT://:9093 
          --override zookeeper.connect=zk-0.zk-headless.liulei.svc.cluster.local:2181,zk-1.zk-headless.liulei.svc.cluster.local:2181,zk-2.zk-headless.liulei.svc.cluster.local:2181    #這裡配置了與zookeeper進行連線，非常重要。格式為：pod名.zookeeper的service名.名稱空間.svc.cluster.local:2181
          --override log.dir=/var/lib/kafka "
        env:
        - name: KAFKA_HEAP_OPTS
          value : "-Xmx512M -Xms512M"
        - name: KAFKA_OPTS
          value: "-Dlogging.level=INFO"
        volumeMounts:
        - name: kafka-data
          mountPath: /var/lib/kafka
        readinessProbe:
          exec:
           command: 
            - sh 
            - -c 
            - "/opt/kafka/bin/kafka-broker-api-versions.sh --bootstrap-server=localhost:9093"
      securityContext:
        runAsUser: 1000
        fsGroup: 1000
  volumeClaimTemplates:
  - metadata:
      name: kafka-data
    spec:
      accessModes: [ "ReadWriteMany" ]
      storageClassName: storageclass-default   #需指定自己的動態儲存類名
      resources:
        requests:
          storage: 1Gi
 

部署成功後檢視pod情況：

驗證kafka是否可用：

1、進入kafka-0命令: kubectl exec -it kafka-0 -nliulei bash
進入容器目錄：cd /opt/kafka/config

2、建立一個名為aaa的topc命令：kafka-topics.sh --create --topic aaa --zookeeper zk-0.zk-headless.liulei.svc.cluster.local:2181,zk-1.zk-headless.liulei.svc.cluster.local:2181,zk-2.zk-headless.liulei.svc.cluster.local:2181 --partitions 3 --replication-factor 2
結果為：
Created topic “aaa”.

3、進入topic為aaa的生產者訊息中心：kafka-console-consumer.sh --topic aaa --bootstrap-server localhost:9093

4、複製新的會話，進入另一個容器kafka-1：kubectl exec -it kafka-1 -nliulei bash

進入消費者，輸入命令：kafka-console-producer.sh --topic aaa --broker-list localhost:9093

輸入:

hello

i lovle you

回車後，可在生產者訊息中心看到訊息

總結

以上步驟和內容都是我一個一個坑踩過來的，親測可用，如果本文對你有幫助的話可以給我點個贊支援一下嗎，比心❤。

歡迎訪問我的部落格，裡面或許會有你感興趣的文章哦