kubernets 部署 Deployment 控制pod的数量

[root@dock01 ~]# cat nginx-deployment.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
spec:
  selector:
    matchLabels:
      app: nginx_20210106
  replicas: 3
  template:
    metadata:
      labels:
        app: nginx_20210106
    spec:
      containers:
      - name: nginx
        image: nginx:1.8
        ports:
        - containerPort: 80
        volumeMounts:
        - mountPath: "/usr/share/nginx/html"
          name: nginx-vol
      volumes:
      - name: nginx-vol
        hostPath:           
         path:  "/var/data"
         
kubectl get pods -l app=nginx_20210106

kubectl create -f nginx-deployment.yaml

[root@dock01 ~]# kubectl get pods -l app=nginx_20210106
NAME                                        READY   STATUS    RESTARTS   AGE
nginx-deployment-20210106-87b5c4dbd-hmvvr   1/1     Running   0          8s
nginx-deployment-20210106-87b5c4dbd-lzzpj   1/1     Running   0          8s
nginx-deployment-20210106-87b5c4dbd-ww77z   1/1     Running   0          8s