通过kubectl describe命令查看具体信息（或查看日志/var/log/message）
[root@MyCentos7 k8s]# kubectl describe pod kubernetes-dashboard-2094756401-kzhnx --namespace=kube-system
Name: kubernetes-dashboard-2094756401-kzhnx
Namespace: kube-system
Node: mycentos7-1/192.168.126.131
Start Time: Tue, 05 Jun 2018 19:28:25 +0800
Labels: app=kubernetes-dashboard
pod-template-hash=2094756401
Status: Pending
IP:
Controllers: ReplicaSet/kubernetes-dashboard-2094756401
Containers:
kubernetes-dashboard:
Container ID:
Image: daocloud.io/megvii/kubernetes-dashboard-amd64:v1.8.0
Image ID:
Port: 9090/TCP
Args:
--apiserver-host=http://192.168.126.130:8080
State: Waiting
Reason: ContainerCreating
Ready: False
Restart Count: 0
Liveness: http-get http://:9090/ delay=30s timeout=30s period=10s #success=1 #failure=3
Volume Mounts:
Environment Variables:
Conditions:
Type Status
Initialized True
Ready False
PodScheduled True
No volumes.
QoS Class: BestEffort
Tolerations:
Events:
FirstSeen LastSeen Count From SubObjectPath Type Reason Message
11m 11m 1 {default-scheduler } Normal Scheduled Successfully assigned kubernetes-dashboard-2094756401-kzhnx to mycentos7-1
11m 49s 7 {kubelet mycentos7-1} Warning FailedSync Error syncing pod, skipping: failed to "StartContainer" for "POD" with ErrImagePull: "image pull failede:latest, this may be because there are no credentials on this request. details: (open /etc/docker/certs.d/registry.access.redhat.com/redhat-ca.crt: no such file or directory)"
11m 11s 47 {kubelet mycentos7-1} Warning FailedSync Error syncing pod, skipping: failed to "StartContainer" for "POD" with ImagePullBackOff: "Back-off pulling image "registry.access.redh
在工作节点（node）上执行
发现此时会pull一个镜像registry.access.redhat.com/rhel7/pod-infrastructure:latest，当我手动pull时，提示如下错误：
[root@MyCentos7-1 k8s]# docker pull registry.access.redhat.com/rhel7/pod-infrastructure:latest
Trying to pull repository registry.access.redhat.com/rhel7/pod-infrastructure ...
open /etc/docker/certs.d/registry.access.redhat.com/redhat-ca.crt: no such file or directory
通过提示的路径查找该文件，是个软连接，链接目标是/etc/rhsm，查看没有rhsm
正常可以这样解决
yum install rhsm
安装完成后，执行一下docker pull registry.access.redhat.com/rhel7/pod-infrastructure:latest
如果依然报错，可参考下面的方案：
wget http://mirror.centos.org/centos/7/os/x86_64/Packages/python-rhsm-certificates-1.19.10-1.el7_4.x86_64.rpm
rpm2cpio python-rhsm-certificates-1.19.10-1.el7_4.x86_64.rpm | cpio -iv --to-stdout ./etc/rhsm/ca/redhat-uep.pem | tee /etc/rhsm/ca/redhat-uep.pem
这两个命令会生成/etc/rhsm/ca/redhat-uep.pem文件.
此时再进行docker pull registry.access.redhat.com/rhel7/pod-infrastructure:latest
就正常了