k8s-高级调度方式-二十一

[root@master ~]# kubectl explain pods.spec.nodeSelector

[root@master schedule]# pwd
/root/manifests/schedule

[root@master schedule]# vim pod-demo.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: pod-demo
  namespace: default
  labels:
    app: myapp
    tier: frontend
  annotations:
    mageedu.com/created-by: "cluster admin"
spec:
  containers:
  - name: myapp
    image: ikubernetes/myapp:v1
  nodeSelector:    #节点选择器
    disktype: ssd    #该pod运行在有disktype=ssd标签的node节点上

[root@master schedule]# kubectl apply -f pod-demo.yaml 
pod/pod-demo created

[root@master schedule]# kubectl get pods -o wide
NAME       READY   STATUS    RESTARTS   AGE     IP           NODE     NOMINATED NODE   READINESS GATES
pod-demo   1/1     Running   0          8m13s   10.244.1.6   node01   <none>           <none>

[root@master schedule]# kubectl get nodes --show-labels |grep node01
node01   Ready    <none>   76d   v1.13.1   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,disktype=ssd,kubernetes.io/hostname=node01

#可见新创建的pod已经运行在node01上了，因为node01上有disktype=ssd标签；

[root@master schedule]# kubectl delete -f pod-demo.yaml

[root@master ~]# kubectl label nodes node02 disktype=harddisk
node/node02 labeled

[root@master schedule]# vim pod-demo.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: pod-demo
  namespace: default
  labels:
    app: myapp
    tier: frontend
  annotations:
    mageedu.com/created-by: "cluster admin"
spec:
  containers:
  - name: myapp
    image: ikubernetes/myapp:v1
  nodeSelector:
    disktype: harddisk        

[root@master schedule]# kubectl get nodes --show-labels |grep node02
node02   Ready    <none>   76d   v1.13.1   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,disktype=harddisk,kubernetes.io/hostname=node02

[root@master schedule]# kubectl get pods -o wide
NAME       READY   STATUS    RESTARTS   AGE    IP           NODE     NOMINATED NODE   READINESS GATES
pod-demo   1/1     Running   0          104s   10.244.2.5   node02   <none>           <none>

[root@master scheduler]# kubectl explain pods.spec.affinity
[root@master scheduler]# kubectl explain pods.spec.affinity.nodeAffinity
preferredDuringSchedulingIgnoredDuringExecution:软亲和，
requiredDuringSchedulingIgnoredDuringExecution:硬亲和，表示必须满足
[root@master ~]# kubectl explain pods.spec.affinity.nodeAffinity.requiredDuringSchedulingIgnoredDuringExecution.nodeSelectorTerms.matchExpressions

#硬亲和性
[root@master schedule]# vim pod-nodeaffinity-demo.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: pod-node-affinity-demo
  namespace: default
  labels:
    app: myapp
    tier: frontend
spec:
  containers:
  - name: myapp
    image: ikubernetes/myapp:v1
  affinity:
    nodeAffinity:
      requiredDuringSchedulingIgnoredDuringExecution:
        nodeSelectorTerms:
        - matchExpressions:
          - key: zone
            operator: In
            values:
            - foo
            - bar

[root@master schedule]# kubectl apply -f pod-nodeaffinity-demo.yaml 
pod/pod-node-affinity-demo created

[root@master schedule]# kubectl get pods    
NAME                     READY   STATUS    RESTARTS   AGE
pod-node-affinity-demo   0/1     Pending   0          76s
 #此时pod是Pending, 是因为没有节点满足条件；

#软亲和性，就算没有符合条件的节点，也会找一个勉强运行；

[root@master schedule]# kubectl delete -f pod-nodeaffinity-demo.yaml 
pod "pod-node-affinity-demo" deleted

[root@master schedule]# vim pod-nodeaffinity-demo2.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: pod-node-affinity-demo2
  namespace: default
  labels:
    app: myapp
    tier: frontend
spec:
  containers:
  - name: myapp
    image: ikubernetes/myapp:v1
  affinity:
    nodeAffinity:
      preferredDuringSchedulingIgnoredDuringExecution:
      - preference:
          matchExpressions:
          - key: zone
            operator: In
            values:
            - foo
            - bar
        weight: 60

[root@master schedule]# kubectl apply -f pod-nodeaffinity-demo2.yaml 
pod/pod-node-affinity-demo2 created

[root@master schedule]# kubectl get pods    #可见pod已经运行了
NAME                      READY   STATUS    RESTARTS   AGE
pod-node-affinity-demo2   1/1     Running   0          74s

pod-node-affinity-demo-2 运行起来了，因为这个pod我们是定义的软亲和性，即使没有符合条件的及诶单，也会找个节点让Pod运行起来