kubernetes 每个node上只能运行一个副本DaemonSet

每个node上只能运行一个副本:

apiVersion: extensions/v1beta1
kind: DaemonSet  #使用DaemonSet的方式运行
metadata:
    name: kube-flannel
    namespace: kube-system
    labels:
       tier: node
       app: flannel
spec:
   template:
      metadata:
          labels:
            tier: node
            app: flannel
      spec:
         hostNetwork: true #指定pod直接使用的node网络，相当于docker run --network=host
         nodeSelector:
            beta.kubernetes.io/arch: amd64
         containers:   #以下定义了两个运行的容器
         - name: kube-flannel
           image: quay.io/coreos/flannel:v0.8.0-amd64
           command: [ "/opt/bin/flanneld", "--ip-masq", "--kube-subnet-mgr" ]
         - name: install-cni
           image: quay.io/coreos/flannel:v0.8.0-amd64
           command: [ "/bin/sh", "-c", "set -e -x;cp -f /etc/kube-flannel/cni-conf.json" ]

docker命令转换成yaml文件：

#docker运行命令
docker run -d \
-v "/proc:/host/proc" \
-v "/sys:/host/sys" \
-v "/:/rootfs" \
--net=host \
prom/node-exporter \
--path.procfs /host/proc \
--path.sysfs /host/sys \
--collector.filesystem.ignored-mount-points "^/(sys|proc|dev|host|etc)($|/)"
#转换成DaemonSet的YAML配置文件
apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
  name: node-exporter
spec:
  template:
    metadata:
      labels:
        app: prometheus
    spec:
      hostNetwork: true  #直接使用host网络
      containers:
      - name: node-exporter
        image: prom/node-exporter
        imagePullPolicy: IfNotPresent
        command:   #设置容器启动命令
        - /bin/node_exporter
        - --path.procfs
        - /host/proc
        - --path.sysfs
        - /host/sys
        - ^(sys|proc|dev|host|etc)($|/)
        volumeMounts:  #通过vloume将host路径/proc、/sys、/映射到容器中
        - name: proc
          mountPath: /host/proc
        - name: sys
          mountPath: /host/sys
        - name: root
          mountPath: /rootfs
      volumes:
      - name: proc
        hostPath: 
          path: /proc
      - name: sys
        hostPath: 
          path: /sys
      - name: root
        hostPath: 
          path: /