kubeadm装单机版kubernetes后，执行的操作

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kubernetes环境

系统环境：centos7.3

版本信息：kubernetes1.10

安装方法：kubeadm

安装完成后如下所示：

[root@worker3 k8s]# kubectl get pods --all-namespaces
NAMESPACE     NAME                              READY     STATUS    RESTARTS   AGE
kube-system   etcd-worker3                      1/1       Running   0          1h
kube-system   kube-apiserver-worker3            1/1       Running   0          1h
kube-system   kube-controller-manager-worker3   1/1       Running   0          1h
kube-system   kube-dns-86f4d74b45-8ptd5         3/3       Running   0          1h
kube-system   kube-flannel-ds-kstl8             1/1       Running   0          38m
kube-system   kube-proxy-txfj4                  1/1       Running   0          1h
kube-system   kube-scheduler-worker3            1/1       Running   0          1h

[root@worker3 shell]# kubectl get node 
NAME      STATUS    ROLES     AGE       VERSION
worker3   Ready     master    1h        v1.10.0

根据创建的mysql-rc.yaml文件

 kubectl create -f  mysql-rc.yaml 

问题如下：

[root@worker3 k8s]# kubectl get pods --all-namespaces
NAMESPACE     NAME                              READY     STATUS    RESTARTS   AGE
default       mysql-b2wgs                       0/1       Pending   0          3s
kube-system   etcd-worker3                      1/1       Running   0          1h
kube-system   kube-apiserver-worker3            1/1       Running   0          1h
kube-system   kube-controller-manager-worker3   1/1       Running   0          1h
kube-system   kube-dns-86f4d74b45-8ptd5         3/3       Running   0          1h
kube-system   kube-flannel-ds-kstl8             1/1       Running   0          34m
kube-system   kube-proxy-txfj4                  1/1       Running   0          1h
kube-system   kube-scheduler-worker3            1/1       Running   0          1h

查看具体信息：

[root@worker3 k8s]# kubectl describe pod  mysql-b2wgs
Name:           mysql-b2wgs
Namespace:      default
Node:           <none>
Labels:         app=mysql
Annotations:    <none>
Status:         Pending
IP:             
Controlled By:  ReplicationController/mysql
Containers:
  mysql:
    Image:      hub.c.163.com/library/mysql
    Port:       3306/TCP
    Host Port:  0/TCP
    Environment:
      MYSQL_ROOT_PASSWORD:  123456
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-kmm7p (ro)
Conditions:
  Type           Status
  PodScheduled   False 
Volumes:
  default-token-kmm7p:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-kmm7p
    Optional:    false
QoS Class:       BestEffort
Node-Selectors:  <none>
Tolerations:     node.kubernetes.io/not-ready:NoExecute for 300s
                 node.kubernetes.io/unreachable:NoExecute for 300s
Events:
  Type     Reason            Age                From               Message
  ----     ------            ----               ----               -------
  Warning  FailedScheduling  19s (x7 over 50s)  default-scheduler  0/1 nodes are available: 1 node(s) had taints that the pod didn't tolerate.

最后出现的错误如下：

 Warning  FailedScheduling  19s (x7 over 50s)  default-scheduler  0/1 nodes are available: 1 node(s) had taints that the pod didn't tolerate.

解决办法：

默认情况下kubernetes中的master并不能运行用户的Pod. 因此需要删除 Train，允许master执行Pod

执行命令如下:

kubectl taint nodes --all node-role.kubernetes.io/master-

参考文档：

https://github.com/kubernetes-incubator/kubespray/issues/2798