Kubernetes: k8s 基础概念

控制节点的状态

[jasper.xu@ip-172-21-39-120 ~]$ kubectl get leases -n kube-system

NAME                                  HOLDER                                                                             AGE
cloud-controller-manager              ip-10-0-100-120.ap-south-1.compute.internal_d235d047-c662-490a-bba7-9930f8e15b49   42d
cloud-provider-extraction-migration   ip-10-0-100-120.ap-south-1.compute.internal_a07c8151-deae-4d3e-9616-583c073290a2   34d
cluster-autoscaler                    cluster-autoscaler-66cffcc58c-rnk94                                                55d
kube-controller-manager               ip-10-0-100-120.ap-south-1.compute.internal_a07c8151-deae-4d3e-9616-583c073290a2   594d
kube-scheduler                        ip-10-0-100-120.ap-south-1.compute.internal_73c79638-c5ea-46c8-95aa-adb511ded71f   594d

一份比较完整的yaml文件介绍

apiVersion: v1  # 必选，API的版本号
kind: Pod       # 必选，类型Pod
metadata:       # 必选，元数据
  name: nginx   # 必选，符合RFC 1035规范的Pod名称
  namespace: default # 可选，Pod所在的命名空间，不指定默认为default，可以使用-n 指定namespace 
  labels:       # 可选，标签选择器，一般用于过滤和区分Pod
    app: nginx
    role: frontend # 可以写多个
  annotations:  # 可选，注释列表，可以写多个
    app: nginx
spec:   # 必选，用于定义容器的详细信息
  initContainers: # 初始化容器，在容器启动之前执行的一些初始化操作
  - command:
    - sh
    - -c
    - echo "I am InitContainer for init some configuration"
    image: busybox
    imagePullPolicy: IfNotPresent
    name: init-container
  containers:   # 必选，容器列表
  - name: nginx # 必选，符合RFC 1035规范的容器名称
    image: nginx:latest         # 必选，容器所用的镜像的地址
    imagePullPolicy: Always     # 可选，镜像拉取策略, IfNotPresent: 如果宿主机有这个镜像，那就不需要拉取了. Always: 总是拉取, Never: 不管是否存储都不拉去
    command: # 可选，容器启动执行的命令，相当于 docker 里的 ENTRYPOINT。args 相当于 cmd
    - nginx 
    - -g
    - "daemon off;"
    workingDir: /usr/share/nginx/html       # 可选，容器的工作目录
    volumeMounts:   # 可选，存储卷配置，可以配置多个
    - name: webroot # 存储卷名称
      mountPath: /usr/share/nginx/html # 挂载目录
      readOnly: true        # 只读
    ports:  # 可选，容器需要暴露的端口号列表
    - name: http    # 端口名称
      containerPort: 80     # 端口号
      protocol: TCP # 端口协议，默认TCP
    env:    # 可选，环境变量配置列表
    - name: TZ      # 变量名
      value: Asia/Shanghai # 变量的值
    - name: LANG
      value: en_US.utf8
    resources:      # 可选，资源限制和资源请求限制
      limits:       # 最大限制设置
        cpu: 1000m
        memory: 1024Mi
      requests:     # 启动所需的资源
        cpu: 100m
        memory: 512Mi
#    startupProbe: # 可选，检测容器内进程是否完成启动。注意三种检查方式同时只能使用一种。
#      httpGet:      # httpGet检测方式，生产环境建议使用httpGet实现接口级健康检查，健康检查由应用程序提供。
#            path: /api/successStart # 检查路径
#            port: 80
    readinessProbe: # 可选，健康检查。注意三种检查方式同时只能使用一种。
      httpGet:      # httpGet检测方式，生产环境建议使用httpGet实现接口级健康检查，健康检查由应用程序提供。
            path: / # 检查路径
            port: 80        # 监控端口
    livenessProbe:  # 可选，健康检查
      #exec:        # 执行容器命令检测方式
            #command: 
            #- cat
            #- /health
    #httpGet:       # httpGet检测方式
    #   path: /_health # 检查路径
    #   port: 8080
    #   httpHeaders: # 检查的请求头
    #   - name: end-user
    #     value: Jason 
      tcpSocket:    # 端口检测方式
            port: 80
      initialDelaySeconds: 60       # 初始化时间
      timeoutSeconds: 2     # 超时时间
      periodSeconds: 5      # 检测间隔
      successThreshold: 1 # 检查成功为2次表示就绪
      failureThreshold: 2 # 检测失败1次表示未就绪
    lifecycle:
      postStart: # 容器创建完成后执行的指令, 可以是exec httpGet TCPSocket
        exec:
          command:
          - sh
          - -c
          - 'mkdir /data/ '
      preStop:
        httpGet:      
              path: /
              port: 80
      #  exec:
      #    command:
      #    - sh
      #    - -c
      #    - sleep 9
  restartPolicy: Always   # 可选，默认为Always，容器故障或者没有启动成功，那就自动该容器，Onfailure: 容器以不为0的状态终止，自动重启该容器, Never:
  #nodeSelector: # 可选，指定Node节点
  #      region: subnet7
  imagePullSecrets:     # 可选，拉取镜像使用的secret，可以配置多个
  - name: default-dockercfg-86258
  hostNetwork: false    # 可选，是否为主机模式，如是，会占用主机端口
  volumes:      # 共享存储卷列表
  - name: webroot # 名称，与上述对应
    emptyDir: {}    # 挂载目录
        #hostPath:              # 挂载本机目录
        #  path: /etc/hosts

创建一个容器（maser01上）

[root@k8s-master01 ~]# cat > pod.yaml << EOF  
apiVersion: v1 # 必选，API的版本号
kind: Pod       # 必选，类型Pod
metadata:       # 必选，元数据
  name: nginx   # 必选，符合RFC 1035规范的Pod名称
  # namespace: default # 可选，Pod所在的命名空间，不指定默认为default，可以使用-n 指定namespace 
  labels:       # 可选，标签选择器，一般用于过滤和区分Pod
    app: nginx
    role: frontend # 可以写多个
  annotations:  # 可选，注释列表，可以写多个
    app: nginx
spec:   # 必选，用于定义容器的详细信息
  containers:   # 必选，容器列表
  - name: nginx # 必选，符合RFC 1035规范的容器名称
    image: nginx:1.15.2    # 必选，容器所用的镜像的地址
    imagePullPolicy: IfNotPresent     # 可选，镜像拉取策略, IfNotPresent: 如果宿主机有这个镜像，那就不需要拉取了. Always: 总是拉取, Never: 不管是否存储都不拉去
    command: # 可选，容器启动执行的命令 ENTRYPOINT, args --> cmd
    - nginx 
    - -g
    - "daemon off;"
    workingDir: /usr/share/nginx/html       # 可选，容器的工作目录
    ports:  # 可选，容器需要暴露的端口号列表
    - name: http    # 端口名称
      containerPort: 80     # 端口号
      protocol: TCP # 端口协议，默认TCP
    env:    # 可选，环境变量配置列表
    - name: TZ      # 变量名
      value: Asia/Shanghai # 变量的值
    - name: LANG
      value: en_US.utf8
  restartPolicy: Always   # 可选，默认为Always，容器故障或者没有启动成功，那就自动该容器，Onfailure: 容器以不为0的状态终止，自动重启该容器, Never:
EOF

# 创建一个pod
[root@k8s-master01 ~]# kubectl create -f pod.yaml 
pod/nginx created

# 查看刚刚创建的Pod
[root@k8s-master01 ~]# kubectl  get po
NAME      READY   STATUS    RESTARTS   AGE
busybox   1/1     Running   4          17h
nginx     1/1     Running   0          5m24s

[root@k8s-master01 ~]# kubectl  get po --show-labels
NAME      READY   STATUS              RESTARTS   AGE   LABELS
busybox   1/1     Running             4          16h   <none>
nginx     0/1     Running             0          90s   app=nginx,role=frontend

# 删除一个po
[root@k8s-master01 ~]# kubectl delete po nginx
pod "nginx" deleted

# 创建到指定的命名空间
[root@k8s-master01 ~]# kubectl create -f pod.yaml  -n kube-public

# 创建命名空间
kubectl create ns ns_name

Pod 三种探针

• Pod探针的4种实现方式
  

  https://kubernetes.io/fr/docs/concepts/workloads/pods/pod-lifecycle/#sondes-du-conteneur
  

  • ExecAction：在容器内执行一个命令，如果返回值为0，则认为容器健康
    
  • TCPSocketAction：通过TCP连接检查容器内的端口是否是通的，如果是通的就认为容器健康
    
  • HTTPGetAction：对指定的 URL 进行 Get 请求，如果 [状态码](https://en.wikipedia.org/wiki/List_of_HTTP_status_codes) 在 `[200,400)` 之间则认为容器健康。生产推荐
    

  1.24 有 grpc 探测
  https://kubernetes.io/fr/docs/concepts/workloads/pods/pod-lifecycle/#sondes-du-conteneur
  

livenessProbe 和 readinessProbe

cat <<\EOF |kubectl create -f -
apiVersion: v1
kind: Pod
metadata:
  name: nginx
spec:
  restartPolicy: Never
  containers:
  - name: nginx
    image: nginx:1.15.12
    imagePullPolicy: IfNotPresent
    command:
    - sh
    - -c
    - sleep 10; nginx -g "daemon off;"
    ports:
    - containerPort: 80
EOF

cat <<\EOF |kubectl create -f -
apiVersion: v1
kind: Pod
metadata:
  name: nginx
spec:
  restartPolicy: Always
  containers:
  - name: nginx
    image: nginx:1.15.12
    imagePullPolicy: IfNotPresent
    command:
    - sh
    - -c
    - sleep 30; nginx -g "daemon off;"
    ports:
    - containerPort: 80
    readinessProbe:  # 可选，健康检查。注意 4 种探测方式只能同时用一种
      failureThreshold: 3  # 检查失败 3 次 表示未就绪
      httpGet:  # 接口检测方式
        path: /index.html  # 检查路径
        port: 80
        scheme: HTTP  # HTTP or HTTPS
        #httpHeaders: # 可选，检查的请求头
        #- name: end-uer
        #  value: Jason
      initialDelaySeconds: 10 # 初始化时间，健康检查延迟执行时间
      periodSeconds: 5  # 检测间隔
      successThreshold: 1  # 检查成功为 1 次表示就绪
      timeoutSeconds: 2 # 超时时间
    livenessProbe:
      failureThreshold: 3  # 检查失败 3 次 表示未就绪
      tcpSocket:  # 端口检测方式
        port: 80
      initialDelaySeconds: 10 # 初始化时间，健康检查延迟执行时间
      periodSeconds: 5  # 检测间隔
      successThreshold: 1  # 检查成功为 1 次表示就绪
      timeoutSeconds: 2 # 超时时间
EOF

配置 startupProbe

ports:
- name: liveness-port
  containerPort: 8080
  hostPort: 8080

livenessProbe:
  httpGet:
    path: /healthz
    port: liveness-port
  failureThreshold: 1
  periodSeconds: 10

startupProbe:
  httpGet:
    path: /healthz
    port: liveness-port
  failureThreshold: 30
  periodSeconds: 10

• 探针检查参数配置
  

  initialDelaySeconds: 60 # 初始化时间。容器启动后要等待多少秒后存活和就绪探测器才被初始化，默认是 0 秒，最小值是 0。
  timeoutSeconds: 2 # 超时时间。默认值是 1 秒。最小值是 1。
  periodSeconds: 5 # 检测间隔。默认是 10 秒。最小值是 1。
  successThreshold: 1 # 检查成功为1次表示就绪。默认值是 1。 存活和启动探测的这个值必须是 1。最小值是 1。
  failureThreshold: 5 # 检测失败5次表示未存活重启容器或未就绪。默认值是 3。最小值是 1。
  

  # 查看已有的配置
  [root@k8s-master01 ~]# kubectl get deployment -n kube-system
  NAME                      READY   UP-TO-DATE   AVAILABLE   AGE
  calico-kube-controllers   1/1     1            1           16h
  coredns                   1/1     1            1           16h
  metrics-server            1/1     1            1           16h
  [root@k8s-master01 ~]#
  [root@k8s-master01 ~]# kubectl edit deploy coredns -n kube-system
  
  

  livenessProbe 定义了容器重启间隔：
  

  每次检查的间隔是10秒，最长超时时间是5秒，也就是单次检查应该是10 + 5 = 15秒（periodSeconds + timeoutSeconds），并不是10 * 5，所以最长的重启时间为（10 + 5）* 5 = 75秒（periodSeconds + timeoutSeconds） * failureThreshold
  

  此时又分为了两种情况：
  1.首次启动时：最长重启时间需要加上initialDelaySeconds，因为需要等待initialDelaySeconds秒后才会执行健康检查。最长重启时间：（periodSeconds + timeoutSeconds） * failureThreshold + initialDelaySeconds
  2.程序启动完成后：此时不需要计入initialDelaySeconds，最长重启时间：（periodSeconds + timeoutSeconds） * failureThreshold
  

  startupProbe 启动探针没有 initialDelaySeconds 初始化时间。
  

preStop 和 preStart

• pod 启动过程
  

  
  

• Pod 平滑退出
  

  
  

  Prestop：先去请求eureka接口，把自己的IP地址和端口号，进行下线，eureka从注册表中删除该应用的IP地址。然后容器进行sleep 90；kill `pgrep java`
  

  这个时间不一定是90s
  

  官方参考：为容器的生命周期事件设置处理函数 https://kubernetes.io/docs/tasks/configure-pod-container/attach-handler-lifecycle-event/
  

  
  

• preStop 和 preStart 使用
  

  cat <<\EOF |kubectl create -f -
  apiVersion: v1
  kind: Pod
  metadata:
    name: nginx
  spec:
    restartPolicy: Always
    containers:
    - name: nginx
      image: nginx:1.15.12
      imagePullPolicy: IfNotPresent
      ports:
      - containerPort: 80
      lifecycle:
        postStart: # 容器创建完成后执行的指令, 可以是 exec httpGet TCPSocket
          exec:
            command:
            - sh
            - -c 
            - 'mkdir /data/'
        preStop:
          exec:
            command:
            - sh
            - -c 
            - sleep 10
  EOF
  

  其它配置
  

  $ cat conf/app-config.yaml
  apiVersion: v1
  data:
    TZ: Asia/Calcutta
    APP_NAMESPACE: ludo-prd
    APP_ENV: prod
    APP_JVM_CONFIG: |-
      -Dfile.encoding=utf-8
      -server
      -XX:+UseG1GC
      -XX:+ExitOnOutOfMemoryError
      -XX:InitialRAMPercentage=75.0
      -XX:MinRAMPercentage=75.0
      -XX:MaxRAMPercentage=75.0
      -XX:+HeapDumpOnOutOfMemoryError
      -XX:HeapDumpPath=/opt/logs/
    PreStop.sh: |-
      #! /bin/bash
      sleep 5
      curl --connect-timeout 5 --max-time 5 -s -i "http://localhost:8080/admin/maintain"
      sleep 40
      curl  --connect-timeout 5 --max-time 5 -s -i -H "Content-Type: application/json" -X POST  http://localhost:8099/actuator/shutdown
      sleep 60
    PreStop_task.sh: |-
      #! /bin/bash
      sleep 5
      curl --connect-timeout 5 --max-time 5 -s -i "http://localhost:8080/admin/maintain"
      sleep 40
      curl --connect-timeout 5 --max-time 5 -s -i "http://localhost:8080/xxljob/shutdown"
      sleep 20
      curl --connect-timeout 5 --max-time 5 -s -i -H "Content-Type: application/json" -X POST  http://localhost:8099/actuator/shutdown
      sleep 40
    app-config.yml: |-
      - type: log
        scan_frequency: 10s
        paths:
          - "/data/logs/dc*.log"
        fields:
          service: ${SERVICE_NAME}
          kafka_topic: ${KAFKA_TOPIC_NAME}
          LOG_TYPE: 'dc'
          POD_IP: '${POD_IP}'
          POD_NAME: '${POD_NAME}'
          NODE_NAME: '${NODE_NAME}'
          POD_NAMESPACE: '${POD_NAMESPACE}'
        json.overwrite_keys: true
        json.keys_under_root: true
        force_close_files: true
        fields_under_root: true
        ignore_older: 24h  # 忽略1天前的日志
        clean_inactive: 25h
        close_inactive: 20m
        #exclude_lines: ['DEBUG']
        #exclude_files: ['.gz$', 'gc.log']
        tags: ['ludo']
        #multiline.pattern: '^([0-9]{4}-[0-9]{2}-[0-9]{2}[[:space:]]*[0-9]{2}:[0-9]{2}:[0-9]{2}\.[0-9]{3}[[:space:]]*\[)'
        #multiline.negate: true
        #multiline.match: after
      - type: log
        scan_frequency: 10s
        paths:
          - "/data/logs/*.error.log"
        fields:
          service: ${SERVICE_NAME}
          kafka_topic: ${KAFKA_TOPIC_NAME}
          LOG_TYPE: 'error'
          POD_IP: '${POD_IP}'
          POD_NAME: '${POD_NAME}'
          NODE_NAME: '${NODE_NAME}'
          POD_NAMESPACE: '${POD_NAMESPACE}'
        #json.overwrite_keys: true
        #json.keys_under_root: true
        force_close_files: true
        fields_under_root: true
        ignore_older: 24h  # 忽略1天前的日志
        clean_inactive: 25h
        close_inactive: 20m
        #exclude_lines: ['DEBUG']
        #exclude_files: ['.gz$', 'gc.log']
        tags: ['ludo']
        multiline.pattern: '^([0-9]{4}-[0-9]{2}-[0-9]{2}[[:space:]][0-9]{2}:[0-9]{2}:[0-9]{2}\.[0-9]{3}[[:space:]]\[)'
        multiline.negate: true
        multiline.match: after
    filebeat.yml: |-
      filebeat.config.inputs:
        path: ${path.config}/conf.d/app-config.yml
        enable: true
        reload.enabled: true
        reload.period: 10s
        max_bytes: 20480  # 单条日志限制20kb
      # ============================== Filebeat modules ==============================
      filebeat.config.modules:
        path: ${path.config}/modules.d/*.yml
        reload.enabled: false
        reload.period: 10s
      # =================================== Filebeat output ===================================
      output.kafka:
        enabled: true
        hosts: ["pfgc-ops-prod-kafka.gamepind.com:9094"]
        topic: '%{[kafka_topic]}'
        partition.round_robin:
          reachable_only: false
        required_acks: 1
        compression: gzip
        max_message_bytes: 1000000
      # =================================== Queue ===================================
      max_procs: 1
      queue.mem:
        events: 2048
        flush.min_events: 1024
        flush.timeout: 2s
  kind: ConfigMap
  metadata:
    name: app-config
    namespace: ludo
  
  
  $ cat ludo-user/deployment.yaml
  apiVersion: apps/v1
  kind: Deployment
  metadata:
    labels:
      app: ludo-user
    name: ludo-user
    namespace: ludo
  spec:
    replicas: 2
    selector:
      matchLabels:
        app: ludo-user
    strategy:
      rollingUpdate:
        maxSurge: 25%
        maxUnavailable: 25%
      type: RollingUpdate
    template:
      metadata:
        annotations:
          prometheus.io/path: /prometheus
          prometheus.io/pathjvm: /actuator/prometheus
          prometheus.io/port: "8080"
          prometheus.io/portjvm: "8099"
          prometheus.io/scrape: "true"
          prometheus.io/scrapejvm: "true"
        labels:
          app: ludo-user
          department: ludo
      spec:
        nodeSelector:
          type: pfgc-ludo-prod-app
        terminationGracePeriodSeconds: 150
        affinity:
          podAntiAffinity:
            preferredDuringSchedulingIgnoredDuringExecution:
            - podAffinityTerm:
                labelSelector:
                  matchLabels:
                    app: ludo-user
                namespaces:
                - ludo
                topologyKey: kubernetes.io/hostname
              weight: 1
        initContainers:
        - image: pfgc-ops-harbor.gamepind.com/devops/skywalking-agent:v8.7.0
          name: skywalking-sidecar
          imagePullPolicy: Always
          command: ['sh']
          args: ['-c', 'mkdir -p /skywalking && /bin/cp -rf /opt/skywalking/gateway-agent /skywalking']
          volumeMounts:
          - mountPath: /skywalking
            name: skywalking
        containers:
        - args:
          - -javaagent:/opt/skywalking/gateway-agent/skywalking-agent.jar
          - -Dfile.encoding=utf-8
          - -server
          - -XX:+UseG1GC
          - -XX:+ExitOnOutOfMemoryError
          - -XX:InitialRAMPercentage=75.0
          - -XX:MinRAMPercentage=75.0
          - -XX:MaxRAMPercentage=75.0
          - -XX:+HeapDumpOnOutOfMemoryError
          - -XX:HeapDumpPath=/opt/logs/
          - -Dspring.profiles.active=prod
          - -jar
          - ludo-user.jar
          command:
          - java
          env:
          - name: POD_IP
            valueFrom:
              fieldRef:
                apiVersion: v1
                fieldPath: status.podIP
          - name: POD_NAME
            valueFrom:
              fieldRef:
                apiVersion: v1
                fieldPath: metadata.name
          - name: SW_AGENT_NAMESPACE
            valueFrom:
              configMapKeyRef:
                name: app-config
                key: APP_NAMESPACE
          - name: SW_AGENT_NAME
            value: "ludo-prd-ludo-user"
          - name: SW_LOGGING_DIR
            value: "/opt/skywalking/logs"
          - name: SW_AGENT_COLLECTOR_BACKEND_SERVICES
            value: "ops-public-skywalking:11800"
          image: ops-harbor.xxx.com/ludo/ludo-user:rc_20220818_150237
          imagePullPolicy: IfNotPresent
          name: ludo-user
          ports:
          - containerPort: 8080
            name: http
            protocol: TCP
          lifecycle:
            preStop:
              exec:
                command:
                - bash
                - -c
                - /opt/PreStop.sh
          readinessProbe:
            httpGet:
              port: 8099
              path: /actuator/health
            periodSeconds: 5
            successThreshold: 1
            failureThreshold: 3
            timeoutSeconds: 5
            initialDelaySeconds: 15
          livenessProbe:
            failureThreshold: 3
            httpGet:
              path: /health
              port: 8080
              scheme: HTTP
            initialDelaySeconds: 60
            periodSeconds: 10
            successThreshold: 1
            timeoutSeconds: 2
          startupProbe:
            failureThreshold: 3
            httpGet:
              path: /actuator/health
              port: 8099
              scheme: HTTP
            periodSeconds: 60
            successThreshold: 1
            timeoutSeconds: 3
          resources:
            limits:
              cpu: "3"
              memory: 6Gi
            requests:
              cpu: "2"
              memory: 6Gi
          volumeMounts:
          - mountPath: /etc/localtime
            name: time
          - mountPath: /opt/logs
            name: logs
          - mountPath: /opt/PreStop.sh
            name: app-config
            subPath: PreStop.sh
          - mountPath: /opt/skywalking
            name: skywalking
        - env:
          - name: TZ
            valueFrom:
              configMapKeyRef:
                name: app-config
                key: TZ
          - name: NODE_NAME
            valueFrom:
              fieldRef:
                apiVersion: v1
                fieldPath: spec.nodeName
          - name: POD_NAMESPACE
            valueFrom:
              fieldRef:
                apiVersion: v1
                fieldPath: metadata.namespace
          - name: POD_NAME
            valueFrom:
              fieldRef:
                apiVersion: v1
                fieldPath: metadata.name
          - name: POD_IP
            valueFrom:
              fieldRef:
                apiVersion: v1
                fieldPath: status.podIP
          - name: KAFKA_TOPIC_NAME
            valueFrom:
              configMapKeyRef:
                name: app-config
                key: APP_NAMESPACE
          - name: SERVICE_NAME
            value: "ludo-user"
          image: docker.elastic.co/beats/filebeat:7.10.2
          imagePullPolicy: IfNotPresent
          name: filebeat-sidecar
          resources:
            limits:
              cpu: 100m
              memory: 200Mi
            requests:
              cpu: 10m
              memory: 10Mi
          volumeMounts:
          - mountPath: /data/logs
            name: logs
          - mountPath: /usr/share/filebeat/filebeat.yml
            name: filebeat-config
            subPath: filebeat.yml
          - mountPath: /usr/share/filebeat/conf.d/
            name: filebeat-config
        imagePullSecrets:
        - name: docker-secret
        securityContext:
          runAsUser: 0
        volumes:
        - configMap:
            defaultMode: 511
            name: app-config
          name: app-config
        - configMap:
            defaultMode: 420
            items:
            - key: filebeat.yml
              path: filebeat.yml
            - key: app-config.yml
              path: app-config.yml
            name: app-config
          name: filebeat-config
        - hostPath:
            path: /usr/share/zoneinfo/Asia/Calcutta
          name: time
        - emptyDir: {}
          name: logs
        - emptyDir: {}
          name: skywalking
  
  

gRPC 探测（1.24默认开启）

cat <<\EOF |kubectl create -f -
apiVersion: v1
kind: Pod
metadata:
  name: etcd
spec:
  restartPolicy: Always
  containers:
  - name: etcd
    image: registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.5.1-0
    imagePullPolicy: IfNotPresent
    command: [ "/usr/local/bin/etcd", "--data-dir", "/var/lib/etcd", "--listen-client-urls", "http://0.0.0.0:2379", "--advertise-client-urls", "http://127.0.0.1:2379", "--log-level", "debug"]
    ports:
    - containerPort: 2379
    livenessProbe:
      grpc:
        port: 2379
      initialDelaySeconds: 10
EOF