Kubernetes 在Master节点上运行DaemonSet

电玩女神 2023-02-28 04:06 6阅读 0赞

> 通常Kubernetes Master节点上会有污点Taints，如果希望DaemonSet运行在Kubernetes所有节点上则需要在Pod Spec层级添加对应tolerations。

### 1. 查看Master节点Tolerations ###

可以通过kuberctl describe nodes 查看指定Master Taints

[root@k8s~]# kubectl describe nodes kubernetes-master01
    Name:               kubernetes-master01
    Roles:              controlplane,etcd
    Labels:             beta.kubernetes.io/arch=amd64
                        beta.kubernetes.io/os=linux
                        kubernetes.io/arch=amd64
                        kubernetes.io/hostname=kubernetes-master01
                        kubernetes.io/os=linux
                        node-role.kubernetes.io/controlplane=true
                        node-role.kubernetes.io/etcd=true
    Annotations:        flannel.alpha.coreos.com/backend-data: {"VtepMAC":"ca:89:74:c4:d1:5d"}
                        flannel.alpha.coreos.com/backend-type: vxlan
                        flannel.alpha.coreos.com/kube-subnet-manager: true
                        flannel.alpha.coreos.com/public-ip: 10.10.10.1
                        node.alpha.kubernetes.io/ttl: 0
                        projectcalico.org/IPv4IPIPTunnelAddr: 10.42.1.1
                        rke.cattle.io/external-ip: 10.10.10.1
                        rke.cattle.io/internal-ip: 10.10.10.1
                        volumes.kubernetes.io/controller-managed-attach-detach: true
    CreationTimestamp:  Sat, 27 Jun 2020 19:06:44 +0800
    Taints:             node-role.kubernetes.io/etcd=true:NoExecute
                        node-role.kubernetes.io/controlplane=true:NoSchedule
    Unschedulable:      false
    Lease:
      HolderIdentity:  kubernetes-master01
      AcquireTime:     <unset>
      RenewTime:       Sun, 19 Jul 2020 17:30:00 +0800

### 2. 在DaemonSet YAML中配置Tolerations ###

在pod spec层级下添加tolerations对应Master节点上的Taints。

---
    apiVersion: apps/v1
    kind: DaemonSet
    metadata:
      name: daemonset-test
      namespace: demo
    spec:
      selector:
        matchLabels:
          app: nginx
      template:
        metadata:
          labels:
            app: nginx
        spec:
          tolerations:
            - key: node-role.kubernetes.io/controlplane
              operator: Exists
              effect: NoSchedule
            - key: node-role.kubernetes.io/etcd
              operator: Exists
              effect: NoExecute
          containers:
            - name: nginx
              image: nginx:latest
              imagePullPolicy: IfNotPresent

### 3. 查看效果 ###

可以看到DaemonSet在Kubernetes所有节点上都运行了一个Pod。

[root@k8s ~]# kubectl get pod -n demo -o wide
    NAME                   READY   STATUS    RESTARTS   AGE   IP            NODE                  NOMINATED NODE   READINESS GATES
    daemonset-test-9tq2n   1/1     Running   0          26m   10.42.2.2     kubernetes-master03   <none>           <none>
    daemonset-test-pxqdf   1/1     Running   0          26m   10.42.0.2     kubernetes-master02   <none>           <none>
    daemonset-test-gxc8j   1/1     Running   0          26m   10.42.1.3     kubernetes-master01   <none>           <none>
    daemonset-test-2vd94   1/1     Running   0          26m   10.42.5.93    kubernetes-node01     <none>           <none>
    daemonset-test-wnsdc   1/1     Running   0          26m   10.42.4.145   kubernetes-node03     <none>           <none>
    daemonset-test-zz9wp   1/1     Running   0          26m   10.42.3.22    kubernetes-node02     <none>           <none>