1. 绑定 Pod

未命名隐藏字段nodeName的 pod 将作为候选进行调度

spec:
  nodeName: node02

但对于已创建的 pod，pod-definition.yaml中的nodeName字段不允许修改，因此将Node分配给 pod 的另一种方法是创建一个绑定对象，并向 pod 绑定 API 发送 post 请求：

Pod-bind-definition.yaml

apiVersion: v1
kind: Binding
metadata:
  name: nginx
target:
  apiVersion: v1
  kind: Node
  name: node02

把 yaml 文件转换成 Json 格式

curl --header "Content-Type:application/json" --request POST --data '{"apiVersion":"v1", "kind": "Binding", ...}' http://$SERVER/api/v1/namespaces/default/pods/$PODNAME/binding

2. Labels

kubectl get all

kubectl get pods -l env=dev | wc -l : 列出env=dev的pod个数（包含header），-l short for --selector

kubectl get pods -l env=dev --no-headers | wc -l : 列出env=dev的pod个数（不包含header）

kubectl label node node01 color=blue : 添加Label

3. Taints - Node

kubectl taint nodes node-name key=value:taint-effect

taint-effect : NoSchedule | PreferNoSchedule | NoExecute

NoExecute : 新Pod不会部署，已存在的节点也会终止

4. Tolerations - Pods

pod-definition.yml

spec:
  tolerations:
  - key: app
    operator: Equal
    value: blue
    effect: NoSchedule

kubectl describe node kubemaster | grep Taint : 查看master node的Taint

kubectl taint node node-name key=value:NoSchedule- : 清除taint

5. Node Selectors

pod-definition.yml

spec:
  nodeSelector:
    size: Large  ##生效前需要先标记 node

kubectl label nodes <node-name> <label-key>=<label-value> : 标记node

6. Node Affinity

pod-definition.yml

spec:
  affinity:
    nodeAffinity:
      requiredDuringSchedulingIgnoredDuringExecution:
        nodeSelectorTerms:
        - matchExpressions:
          - key: size
            operator: NotIn | In | Exists ## Exists运算符甚至不需要下面的values
            values:
            - Large
            - Medium

Available ：

• requiredDuringSchedulingIgnoredDuringExecution
• preferredDuringSchedulingIgnoredDuringExecution

Planned :

• requiredDuringSchedulingrequiredDuringExecution

DuringScheduling：Pod 不存在且是首次创建

7. Multiple Schedulers

kube-scheduler.service

ExecStart=/usr/local/bin/kube-scheduler \\
  --config=/etc/kubernetes/config/kube-scheduler.yaml \\
  --scheduler-name= default-scheduler

/etc/kubernetes/manifests/kube-scheduler.yaml

apiVersion: v1
kind: Pod
metadata:
  name: my-custom-scheduler
  namespace: kube-system
spec:
  containers:
  - command:  ##包含用于启动调度程序的命令和相关选项
    - kube-scheduler
    - --address=127.0.0.1
    - --kubeconfig=/etc/kubernetes/scheduler.conf
    - --leader-elect=true  ##没有多个主节点运行scheduler就设置为false
    - --scheduler-name=my-custom-scheduler  ##设置调度程序的自定义名称
    - --lock-object-name=my-custom-scheduler  ##用于区分自定义调度程序和默认调度程序
    image: k8s.gcr.io/kube-scheduler-amd64:v1.11.3
    name: kube-scheduler

pod-definition.yaml

apiVersion: v1
kind: Pod
metadata:
  name: nginx
spec:
  containers:
  - image: nginx
    name: nginx
  schedulerName: my-custom-scheduler

kubectl get events：查看哪个 scheduler 调用

kubectl logs my-custom-scheduler --name-space=kube-system：查看日志

kubectl create configmap my-scheduler-config --from-file=/root/my-scheduler-config.yaml -n kube-system：创建 configmap