k8s学习（23）：固定节点调度

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指定调度节点

1 Pod.spec.nodeName将Pod直接调度到指定的Node节点上，会跳过Scheduler的调度策略，该匹配规则是强制匹配

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apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  myweb
spec:
  replicas: 7
  template:
    metadata:
      labels:
        app: myweb
    spec:
      nodeName: k8s-node01
      containers:
      - name: myweb
        image: hub.test.com/library/myapp:v1
        ports:
        - containerPort: 80

运行一下看看效果

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[root@k8s-master node]# kubectl apply -f deploy.yaml 
deployment.extensions/myweb created
[root@k8s-master node]# kubectl get pods
NAME                     READY   STATUS              RESTARTS   AGE
myapp                    1/1     Running             0          25m
myweb-7bff67bccc-4wbpm   0/1     ContainerCreating   0          2s
myweb-7bff67bccc-5m24f   0/1     ContainerCreating   0          2s
myweb-7bff67bccc-8z6dh   0/1     ContainerCreating   0          2s
myweb-7bff67bccc-9gdlp   0/1     ContainerCreating   0          2s
myweb-7bff67bccc-9vnnz   0/1     ContainerCreating   0          2s
myweb-7bff67bccc-rzckd   0/1     ContainerCreating   0          2s
myweb-7bff67bccc-s49tp   0/1     ContainerCreating   0          2s
myweb-7bff67bccc-td6kn   0/1     ContainerCreating   0          2s
myweb-7bff67bccc-vrpsn   0/1     ContainerCreating   0          2s
myweb-7bff67bccc-w7568   0/1     ContainerCreating   0          2s
pod-taint-toleration     1/1     Running             0          13m
[root@k8s-master node]# kubectl get pods -o wide
NAME                     READY   STATUS    RESTARTS   AGE   IP             NODE         NOMINATED NODE   READINESS GATES
myapp                    1/1     Running   0          25m   10.244.1.120   k8s-node01   <none>           <none>
myweb-7bff67bccc-4wbpm   1/1     Running   0          6s    10.244.1.123   k8s-node01   <none>           <none>
myweb-7bff67bccc-5m24f   1/1     Running   0          6s    10.244.1.128   k8s-node01   <none>           <none>
myweb-7bff67bccc-8z6dh   1/1     Running   0          6s    10.244.1.130   k8s-node01   <none>           <none>
myweb-7bff67bccc-9gdlp   1/1     Running   0          6s    10.244.1.121   k8s-node01   <none>           <none>
myweb-7bff67bccc-9vnnz   1/1     Running   0          6s    10.244.1.122   k8s-node01   <none>           <none>
myweb-7bff67bccc-rzckd   1/1     Running   0          6s    10.244.1.124   k8s-node01   <none>           <none>
myweb-7bff67bccc-s49tp   1/1     Running   0          6s    10.244.1.127   k8s-node01   <none>           <none>
myweb-7bff67bccc-td6kn   1/1     Running   0          6s    10.244.1.125   k8s-node01   <none>           <none>
myweb-7bff67bccc-vrpsn   1/1     Running   0          6s    10.244.1.129   k8s-node01   <none>           <none>
myweb-7bff67bccc-w7568   1/1     Running   0          6s    10.244.1.126   k8s-node01   <none>           <none>
pod-taint-toleration     1/1     Running   0          13m   10.244.2.210   k8s-node02   <none>           <none>

可以看到，所有的Pod被调度到k8s-node01节点上

2 Pod.spec.nodeSelector：通过kubernetes的label-selector机制选择节点，由调度器调度策略匹配label，而后调度Pod到目标节点，该匹配规则属于强制约束

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apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: myweb-2
spec:
  replicas: 2
  template:
    metadata:
      labels:
        app: myweb-2
    spec:
      nodeSelector:
        disk: ssd
      containers:
      - name: myweb-2
        image: hub.test.com/library/myapp:v1
        ports:
        - containerPort: 80

运行该deploy

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[root@k8s-master node]# kubectl apply -f deploy2.yaml 
deployment.extensions/myweb created
[root@k8s-master node]# kubectl get pods
NAME                     READY   STATUS    RESTARTS   AGE
myweb-689f546447-8tftj   0/1     Pending   0          3s
myweb-689f546447-xsdz4   0/1     Pending   0          3s
myweb-689f546447-z2zp9   0/1     Pending   0          3s

设置node label为disk=ssd，可以看到pod成功被调度到node上

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[root@k8s-master node]# kubectl label node k8s-node01 disk=ssd
node/k8s-node01 labeled
[root@k8s-master node]# kubectl get pods
NAME                     READY   STATUS    RESTARTS   AGE
myweb-689f546447-8tftj   1/1     Running   0          60s
myweb-689f546447-xsdz4   1/1     Running   0          60s
myweb-689f546447-z2zp9   1/1     Running   0          60s