# 为了方面演示，增加到三个节点，效果更加明显
[root@centos-7-51 ~]# kubectl get node 
NAME          STATUS   ROLES    AGE     VERSION
centos-7-51   Ready    master   10d     v1.18.12
centos-7-52   Ready    master   10d     v1.18.12
centos-7-53   Ready    master   10d     v1.18.12
centos-7-54   Ready    worker   10d     v1.18.12
centos-7-55   Ready    worker   10d     v1.18.12
centos-7-56   Ready    worker   7m58s   v1.18.12
[root@centos-7-51 ~]# kubectl label node centos-7-54 ssd=true  # 打上标签方便区分
[root@centos-7-51 ~]# kubectl label node centos-7-55 ssd=true
[root@centos-7-51 ~]# kubectl label node centos-7-54 cpu=high
[root@centos-7-51 ~]# kubectl label node centos-7-56 cpu=high

节点选择器有两种，一种时直接指定nodeName，另一种是通过 nodeSelector 来根据标签选择：
● 指定nodeName

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deploy
spec:
  replicas: 5
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx-demo
        image: linuxduduniao/nginx:v1.0.0
      nodeName: centos-7-56

[root@centos-7-51 ~]# kubectl get pod -o wide # 全部调度到 centos-7-56 节点
NAME                           READY   STATUS    RESTARTS   AGE     IP            NODE          NOMINATED NODE   READINESS GATES
nginx-deploy-5648cd896-64ktx   1/1     Running   0          5m54s   172.16.5.11   centos-7-56   <none>           <none>
nginx-deploy-5648cd896-fgx75   1/1     Running   0          5m54s   172.16.5.13   centos-7-56   <none>           <none>
nginx-deploy-5648cd896-fvrlq   1/1     Running   0          5m54s   172.16.5.12   centos-7-56   <none>           <none>
nginx-deploy-5648cd896-hzljl   1/1     Running   0          5m54s   172.16.5.15   centos-7-56   <none>           <none>
nginx-deploy-5648cd896-qwrb5   1/1     Running   0          5m54s   172.16.5.14   centos-7-56   <none>           <none>

使用nodeSelector

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deploy
spec:
  replicas: 5
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx-demo
        image: linuxduduniao/nginx:v1.0.0
      nodeSelector:
        ssd: "true"
        cpu: high

[root@centos-7-51 ~]# kubectl get pod -o wide # nodeSelector多个选项之间是 and 关系
NAME                            READY   STATUS    RESTARTS   AGE   IP             NODE          NOMINATED NODE   READINESS GATES
nginx-deploy-6d5b594bf5-b7s68   1/1     Running   0          14s   172.16.3.134   centos-7-54   <none>           <none>
nginx-deploy-6d5b594bf5-kv5kn   1/1     Running   0          14s   172.16.3.132   centos-7-54   <none>           <none>
nginx-deploy-6d5b594bf5-sxsgv   1/1     Running   0          11s   172.16.3.135   centos-7-54   <none>           <none>
nginx-deploy-6d5b594bf5-t2p8n   1/1     Running   0          11s   172.16.3.136   centos-7-54   <none>           <none>
nginx-deploy-6d5b594bf5-xrrhp   1/1     Running   0          14s   172.16.3.133   centos-7-54   <none>           <none>