在看《k8s权威指南》实战过程中遇到了一个问题：
我打算发布一个mysql-rc.yaml到集群中，我的mysql-rc.yaml文件是这样的
apiVersion: v1
kind: ReplicationController
metadata:
name: mysql
spec:
replicas: 1
#定义RC标签选择
selector:
app: mysql
#定义Pod模板
template:
metadata:
labels:
app: mysql
spec:
#Pod内容器定义
containers:
- name: mysql
image: mysql
ports:
- containerPort: 3306
env:
- name: MYSQL_ROOT_PASSWORD
value: "123456"
发布到集群出现问题：
[root@kubecon ~]# kubectl create -f mysql-rc.yaml
replicationcontroller "mysql" created
[root@kubecon ~]# kubectl get rc
NAME DESIRED CURRENT READY AGE
mysql 1 1 0 1m
[root@kubecon ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
mysql-bwnlk 0/1 ContainerCreating 0 1m
pod服务一直处于 ContainerCreating状态
Solution
查看相关日志
[root@kubecon ~]# kubectl describe po mysql-bwnlk
Name: mysql-bwnlk
Namespace: default
Node: 127.0.0.1/127.0.0.1
Start Time: Thu, 04 Jan 2018 10:20:45 +0800
Labels: app=mysql
Status: Pending
IP:
Controllers: ReplicationController/mysql
Containers:
mysql:
Container ID:
Image: daocloud.io/library/mysql
Image ID:
Port: 3306/TCP
State: Waiting
Reason: ContainerCreating
Ready: False
Restart Count: 0
Volume Mounts: <none>
Environment Variables:
MYSQL_ROOT_PASSWORD: 123456
Conditions:
Type Status
Initialized True
Ready False
PodScheduled True
No volumes.
QoS Class: BestEffort
Tolerations: <none>
Events:
FirstSeen LastSeen Count From SubObjectPath Type Reason Message
--------- -------- ----- ---- ------------- -------- ------ -------
3m 3m 1 {default-scheduler } Normal Scheduled Successfully assigned mysql-bwnlk to 127.0.0.1
3m 20s 5 {kubelet 127.0.0.1} Warning FailedSync Error syncing pod, skipping: failed to "StartContainer" for "POD" with ErrImagePull: "image pull failed for registry.access.redhat.com/rhel7/pod-infrastructure: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)"
2m 8s 10 {kubelet 127.0.0.1} Warning FailedSync Error syncing pod, skipping: failed to "StartContainer" for "POD" with ImagePullBackOff: "Back-off pulling image \"registry.access.redhat.com/rhel7/pod-infrastructure:latest\""
关键问题出现
Error syncing pod, skipping: failed to "StartContainer" for "POD" with ErrImagePull: "image pull failed for registry.access.redhat.com/rhel7/pod-infrastructure: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)"
看到registry.access.redhat.com/rhel7/pod-infrastructure:latest我感觉很怪，我之前已经设置好仓库为grc.io，为什么去拉取这个镜像，怀疑是不是什么没有安装好。
尝试运行docker pull registry.access.redhat.com/rhel7/pod-infrastructure:latest，提示redhat-ca.crt: no such file or directory。
[root@kubecon ~]# 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
ls查看该文件是个软连接，链接目标是/etc/rhsm
[root@kubecon ~]# ls -l /etc/docker/certs.d/registry.access.redhat.com/redhat-ca.crt
lrwxrwxrwx 1 root root 27 1月 3 21:06 /etc/docker/certs.d/registry.access.redhat.com/redhat-ca.crt -> /etc/rhsm/ca/redhat-uep.pem
查看没有rhsm
[root@kubecon ~]# ls /etc/rhsm
ls: 无法访问/etc/rhsm: 没有那个文件或目录
尝试安装yum install rhsm
yum install rhsm -y
#如果上一步没有源的话，请试试
#yum -y install python-rhsm
#如果上一步还不能安装rhsm的话请下载rpm包安装
#https://www.rpmfind.net/linux/rpm2html/search.php?query=python-rhsm
#wget https://www.rpmfind.net/linux/centos/7.4.1708/os/x86_64/Packages/python-rhsm-1.19.9-1.el7.x86_64.rpm
#rpm -ivh python-rhsm-*.rpm
安装之后查看产生了/etc/rhsm文件夹,再次运行kubectl get pods
问题解决～
[root@kubecon ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
mysql-bwnlk 1/1 Running 0 52m
