kubernetes 中遇见的一些坑(持续更新)

一、官网镜像无法下载

解决方法：需要翻墙

配置docker翻墙机：

cat /usr/lib/systemd/system/docker.service

[Service]

Environment="HTTP_PROXY=http://10.53.16.201:1080/"

重启docker服务

二、pause k8s镜像下载失败

pod启动失败，查看pod详情(kubectl describe pods podname)

    Events:
      FirstSeen LastSeen    Count   From            SubobjectPath   Type        Reason      Message
      --------- --------    -----   ----            -------------   --------    ------      -------
      56s       56s     1   {default-scheduler }            Normal      Scheduled   Successfully assigned nfs-rc-fc2w8 to duni-node1
      11s       11s     1   {kubelet duni-node1}            Warning     FailedSync  Error syncing pod, skipping: failed to "StartContainer" for "POD" with ErrImagePull: "image pull failed for gcr.io/google_containers/pause-amd64:3.0, this may be because there are no credentials on this request.  details: (Get https://gcr.io/v1/_ping: dial tcp 74.125.203.82:443: i/o timeout)"

解决：

找到翻墙机器下载镜像，上传到自己的私有仓库:xxx.xxxx.xxxx/pause-amd64:3.0

gcr.io/google_containers/pause-amd64:3.0

修改kubelet 配置：

--pod-infra-container-image=xxx.xxxx.xxxx/pause-amd64:3.0

重启: kubelet

三、权限问题

通过rc配置文件起pod，rc中配置了privileged为true，发现pod状态一直Running不起来，查看pod详情发现

    [root@docker tmp]# kubectl describe pods nfs-rc-acbo1
    Name:       nfs-rc-acbo1
    Namespace:  default
    Node:       duni-node2
    Labels:     role=nfs-server
    Status:     Pending
    IP:     
    Controllers:    ReplicationController/nfs-rc
    Containers:
      nfs-server:
        Image:          192.168.100.90:5000/nfs-data
        Port:           2049/TCP
        Volume Mounts:      <none>
        Environment Variables:  <none>
    Conditions:
      Type      Status
      PodScheduled  True 
    No volumes.
    QoS Class:  BestEffort
    Tolerations:    <none>
    Events:
      FirstSeen LastSeen    Count   From            SubobjectPath   Type        Reason          Message
      --------- --------    -----   ----            -------------   --------    ------          -------
      27s       27s     1   {default-scheduler }            Normal      Scheduled       Successfully assigned nfs-rc-acbo1 to duni-node2
      27s       27s     1   {kubelet duni-node2}            Warning     FailedValidation    Error validating pod nfs-rc-acbo1.default from api, ignoring: spec.containers[0].securityContext.privileged: Forbidden: disallowed by policy

解决：

修改所有node以及master节点的k8s配置文件 vim /etc/kubernetes/config

$ KUBE_ALLOW_PRIV="--allow-privileged=true"
$ systemctl restart kube-apiserver

四、getsockopt: connection timed out’问题

如果安装的docker版本为1.13及以上，并且网络畅通，flannel、etcd都正常，但还是会出现getsockopt: connection timed out'的错误，则可能是iptables配置问题。具体问题：

Error: 'dial tcp 10.233.50.3:8443: getsockopt: connection timed out

docker从1.13版本开始，可能将iptables FORWARD chain的默认策略设置为DROP，从而导致ping其他Node上的Pod IP失败，遇到这种问题时，需要手动设置策略为ACCEPT：

sudo iptables -P FORWARD ACCEPT

使用iptables -nL命令查看，发现Forward的策略还是drop，可是我们明明执行了iptables -P FORWARD ACCEPT。原来，docker是在这句话执行之后启动的，需要每次在docker之后再执行这句话。。。这么做有点太麻烦了，所以我们修改下docker的启动脚本：

vi /usr/lib/systemd/system/docker.service

[Service] Type=notify # the default is not to use systemd for cgroups because the delegate issues still # exists and systemd currently does not support the cgroup feature set required # for containers run by docker

ExecStart=/usr/bin/dockerd $DOCKER_NETWORK_OPTIONS $DOCKER_OPTS $DOCKER_DNS_OPTIONS # 添加这行操作，在每次重启docker之前都会设置iptables策略为ACCEPT

ExecStartPost=/sbin/iptables -I FORWARD -s 0.0.0.0/0 -j ACCEPT

ExecReload=/bin/kill -s HUP $MAINPID

五、部署 Ingress Controller 的问题

部署完了后端就得把最重要的组件 Nginx+Ingres Controller(官方统一称为 Ingress Controller) 部署上

➜ ~ kubectl create -f nginx-ingress-controller.yaml daemonset "nginx-ingress-lb" created

注意：官方的 Ingress Controller 有个坑，至少我看了 DaemonSet 方式部署的有这个问题：没有绑定到宿主机 80 端口，也就是说前端 Nginx 没有监听宿主机 80 端口(这还玩个卵啊)；所以需要把配置搞下来自己加一下 hostNetwork，截图如下

hostNetwork: true ##这行

containers:

- name: nginx-ingress-controller

image: quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.9.0

六、问题6

kube-proxy: E0103 18:30:04.060770 40611 proxier.go:977] conntrack return with error: error looking for path of conntrack: exec: "conntrack": executable file not found in $PATH

yum install conntrack-tools -y

七、api-server 多台api

uthentication.go:58] Unable to authenticate the request due to an error: [invalid bearer token, [invalid bearer token, [invalid bearer token, crypto/rsa: verification error, invalid bearer token

update-ca-trust

八、容器状态为Terminating

强制删除状态STATUS为Terminating：

kubectl delete pod kubernetes-dashboard-5c7d5fc568-gq7lj --grace-period=0 --force -n kube-system



九、访问dashboard的问题

Unauthorized问题

{ "kind": "Status",

"apiVersion": "v1",

"metadata": { },

"status": "Failure",

"message": "Unauthorized",

"reason": "Unauthorized",

"code": 401 }

解决方法：

新建basic_auth_file文件，并在其中添加：

admin,admin,1002

文件内容格式：password,username,uid

然后在api-server配置文件（即上面的配置文件）中添加--=/etc/kubernetes/basic_auth_file

保存重启kube-apiserver：