Node Selector

2023-06-02 02:01| 来源: 网络整理| 查看: 265

k8s本身就会根据资源等信息将pod分配到合适的node上，但有些场景下，我们需要更强的控制，比如云平台的租户只能使用购买的节点。有3种方式可以实现：node selector，affinity和node name。

Node Selector

Node Selector是指定pod分配到指定node上最简单的方法，使用Pod中的nodeSelector属性来实现。Node Selector会指定key-value pairs，pod会被分配到特定node上，该node具有所有指定key-value pairs对应labels。通常只有一对key-value。

下面命令为node设置label和查看node上label。

kubectl label nodes = kubectl get nodes --show-labels kubectl describe node "nodename"

下面创建pod并指定node selector。但通常会使用Deployment等方式创建pod，同样也可以设置node selector. kubectl label node k8s-n2 disktype=ssd #给k8s-n2节点增加标签

apiVersion: v1 kind: Pod metadata: name: nginx labels: env: test spec: containers: - name: nginx image: nginx imagePullPolicy: IfNotPresent nodeSelector: disktype: ssd

实际使用 kubectl label node cn-shenzhen.10.0.21.33 apptype=dwgtodfx-service kubectl label node cn-shenzhen.10.0.21.33 apptype- #减去标签 nodeSelector: apptype: @NODE_LABEL@

注意：当集群中不存在NodeSelector指定的Node，即使集群中还有其他可供使用的Node，这个Pod也不会被成功调度。

NodeSelector将会被继续使用，但最终会被废弃。

Affinity

相对于node selector，affinity更加灵活。除了node selector提供的label强制匹配外， affinity具有3个优势：1. 可以反向指定anti-affinity；2. 可以指定弱匹配，prefer，即使不匹配，也可能被分配； 3.可提供node中pod之间的限制，不仅仅是node层级。

Affinity分为Node Affinity和Inter-pod Affinity.前者在使用node label进行选择，后者根据相同node上的pod label进行选择。

-Node Affinity

Node Affinity类似于Node Selector，但包括2种类型：requiredDuringSchedulingIgnoredDuringExecution和preferredDuringSchedulingIgnoredDuringExecution。前者表示强匹配，后者表示弱匹配。这2种类型都是pod schedule时起作用，运行时忽略。即pod分配之后，修改label不会影响已经分配的pod。后面计划提供requiredDuringSchedulingRequiredDuringExecution功能。

下面是node affinity示例。node必须具有label,其key为http://kubernetes.io/e2e-az-name，其value为e2e-az1或e2e-az2，同时，更倾向于具有label，其key为another-node-label-key，其value为another-node-label-value。

kubectl label node cn-shenzhen.10.0.21.33 percona80-master.devops=true pods: affinity: rules: nodeAffinity: requiredDuringSchedulingIgnoredDuringExecution: nodeSelectorTerms: - matchExpressions: - key: percona80-master.devops operator: In values: - "true"

物业sass模板

apiVersion: apps/v1 kind: Deployment metadata: name: ${service} labels: app.kubernetes.io/name: ${service} app.kubernetes.io/version: 0.0.0 app.kubernetes.io/instance: ${service} environment: ${env} #环境变量 spec: replicas: ${replicas} #副本数 revisionHistoryLimit: 3 selector: matchLabels: app.kubernetes.io/name: ${service} strategy: rollingUpdate: maxSurge: 25% maxUnavailable: 25% type: RollingUpdate template: metadata: labels: app.kubernetes.io/name: ${service} app.kubernetes.io/version: 0.0.0 app.kubernetes.io/instance: ${service} micrometer-registry-prometheus: "true" logging: "false" spec: serviceAccountName: default dnsPolicy: Default imagePullSecrets: - name: gemdale-registry.cn-shenzhen.cr.aliyuncs.com-secret containers: - name: ${service} image: ${image} imagePullPolicy: IfNotPresent command: - java args: - -Duser.timezone=Asia/Shanghai - -XX:+UseContainerSupport - -XX:InitialRAMPercentage=80.0 - -XX:MaxRAMPercentage=80.0 - -jar - /data/var/www/service/${service}/${jar_name}.jar env: - name: HOST_IP valueFrom: fieldRef: fieldPath: status.hostIP - name: WFWAPP value: wfw-applog volumeMounts: - mountPath: /data/appdata/ name: appdata - mountPath: /data/config-repo/ name: config-repo - mountPath: /data/logs/ name: logs - mountPath: /mnt/hgfs/ name: mnt-hgfs readinessProbe: tcpSocket: port: ${port} initialDelaySeconds: 30 periodSeconds: 15 ports: - containerPort: ${port} name: http resources: requests: memory: ${requests_memory} #内存资源下限比如：500Mi、1Gi cpu: ${requests_cpu} #CPU资源下限，比如：0.1、0.25 limits: memory: ${limit_memory} #内存资源上限比如：800Mi、2Gi cpu: ${limit_cpu} #CPU资源上限，比如：0.5、1、2 affinity: nodeAffinity: requiredDuringSchedulingIgnoredDuringExecution: nodeSelectorTerms: - matchExpressions: - key: microservice operator: In values: - "true" volumes: - hostPath: path: /data/appdata/ type: DirectoryOrCreate name: appdata - hostPath: path: /data/config-repo/ type: DirectoryOrCreate name: config-repo - hostPath: path: /data/logs/ type: DirectoryOrCreate name: logs - hostPath: path: /mnt/hgfs/ type: DirectoryOrCreate name: mnt-hgfs --- apiVersion: v1 kind: Service metadata: name: ${service} labels: app.kubernetes.io/name: ${service} app.kubernetes.io/version: 0.0.0 app.kubernetes.io/instance: ${service} environment: ${env} spec: type: ClusterIP ports: - name: http port: 80 protocol: TCP targetPort: ${port} - name: https port: 443 protocol: TCP targetPort: ${port} selector: app.kubernetes.io/name: ${service} app.kubernetes.io/instance: ${service}

智能审图模板

apiVersion: apps/v1 kind: Deployment metadata: name: @APP_NAME@ labels: app: @APP_NAME@ spec: replicas: @REPLICAS@ revisionHistoryLimit: 10 selector: matchLabels: app: @APP_NAME@ template: metadata: labels: app: @APP_NAME@ spec: containers: - name: @APP_NAME@ image: ${IMAGE} ports: - containerPort: @targetPort@ protocol: TCP imagePullPolicy: IfNotPresent env: - name: protocol value: "http" - name: domainPrefix value: "://10.0.21.21" - name: app_env value: ":" - name: domainDelimiter value: "300" - name: domain value: "48" - name: nacos_namespace value: "c357bb7a-36a8-4880-a5ae-9778119688a5" - name: user_name value: "nacos" - name: password value: "Nacos@qaz" livenessProbe: failureThreshold: 3 httpGet: path: /actuator port: @targetPort@ scheme: HTTP initialDelaySeconds: 37 periodSeconds: 10 successThreshold: 1 timeoutSeconds: 1 readinessProbe: failureThreshold: 3 httpGet: path: /actuator port: @targetPort@ scheme: HTTP initialDelaySeconds: 3 periodSeconds: 10 successThreshold: 1 timeoutSeconds: 1 resources: limits: cpu: @LIMIT_CPU@ memory: @LIMIT_MEMORY@ requests: cpu: @REQUEST_CPU@ memory: @REQUEST_MEMORY@ startupProbe: failureThreshold: 3 httpGet: path: /actuator port: @targetPort@ scheme: HTTP initialDelaySeconds: 17 periodSeconds: 10 successThreshold: 1 timeoutSeconds: 1 ######### 配置volume mount ########### volumeMounts: - name: volumn-logging-springboot mountPath: /gemdale/logs affinity: nodeAffinity: requiredDuringSchedulingIgnoredDuringExecution: nodeSelectorTerms: - matchExpressions: - key: dwgtodfx-service operator: In values: - "true" volumes: - name: volumn-logging-springboot hostPath: type: DirectoryOrCreate path: /data/logs/@APP_NAME@ ############################### --- apiVersion: v1 kind: Service metadata: name: @APP_NAME@ namespace: default labels: app: @APP_NAME@ spec: ports: - port: @port@ targetPort: @targetPort@ @NodePort@ selector: app: @APP_NAME@ type: @PORT_TYPE@

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