kubernetes调度之NodeSelector

http://blog.csdn.net/tiger435/article/details/73650147

本文主要介绍kubernetes调度框架中的NodeName和NodeSelector。

1 NodeName

Pod.spec.nodeName用于强制约束将Pod调度到指定的Node节点上，这里说是“调度”，但其实指定了nodeName的Pod会直接跳过Scheduler的调度逻辑，直接写入PodList列表，该匹配规则是强制匹配。

例子：

apiVersion: extensions/v1beta1kind: Deploymentmetadata:  name: tomcat-deployspec:  replicas: 1  template:    metadata:      labels:        app: tomcat-app    spec:      nodeName: k8s.node1 #指定调度节点为k8s.node1      containers:      - name: tomcat        image: tomcat:8.0        ports:        - containerPort: 8080
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2 NodeSelector

Pod.spec.nodeSelector是通过kubernetes的label-selector机制进行节点选择，由scheduler调度策略MatchNodeSelector进行label匹配，调度pod到目标节点，该匹配规则是强制约束。启用节点选择器的步骤为：

• Node添加label标记

#标记规则：kubectl label nodes <node-name> <label-key>=<label-value>kubectl label nodes k8s.node1 cloudnil.com/role=dev#确认标记[e-mail]1:~# kubectl get nodes k8s.node1 --show-labelsNAME        STATUS    AGE       LABELSk8s.node1   Ready     29d       beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,cloudnil.com/role=dev,kubernetes.io/hostname=k8s.node1
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• Pod定义中添加nodeSelector

apiVersion: extensions/v1beta1kind: Deploymentmetadata:  name: tomcat-deployspec:  replicas: 1  template:    metadata:      labels:        app: tomcat-app    spec:      nodeSelector:        cloudnil.com/role: dev #指定调度节点为带有label标记为：cloudnil.com/role=dev的node节点      containers:      - name: tomcat        image: tomcat:8.0        ports:        - containerPort: 8080