k8s常见问题

1. 驱逐节点pod

kubectl drain hostname --force --ignore-daemonsets --delete-local-data

2.删除节点

kubectl delete node hostname

3. 节点删除后重新加入

kubeadm join 10.111.3.6:6443 --token ahzyvb.uz0k2j039zh4zuxf
--discovery-token-ca-cert-hash sha256:edce9b33fc11c5b33c8a2d8efb1891c2f41a20922581cdd678044cd69d650723

4.重新加入报错

出现如上问题的主要原因是之前 kubeadm init 初始化过，所以一些配置文件及服务均已存在，重新执行 kubeadm join 时必然
会导致冲突，解决方法如下：
   1.先执行 kubeadm reset，重新初始化节点配置

   2.然后执行 kubeadm join 添加节点到集群（如果 token 失效，到主节点执行：kubeadm token create 重新生成）kubeadm token create --print-join-command

   3.  删除node1容器    docker ps -qa | xargs docker rm -f

   4. 删除node1旧的配置文件   rm -f /etc/kubernetes/kubelet.conf        systemctl restart docker kubelet       rm -f /etc/kubernetes/pki/ca.crt  

   5. kubeadm join 10.111.3.6:6443 --token ahzyvb.uz0k2j039zh4zuxf
--discovery-token-ca-cert-hash sha256:edce9b33fc11c5b33c8a2d8efb1891c2f41a20922581cdd678044cd69d650723

5. 

  

[root@k8s-master manifests]# kubectl get cs
NAME                 STATUS      MESSAGE                                                                                     ERROR
scheduler            Unhealthy   Get http://127.0.0.1:10251/healthz: dial tcp 127.0.0.1:10251: connect: connection refused
controller-manager   Unhealthy   Get http://127.0.0.1:10252/healthz: dial tcp 127.0.0.1:10252: connect: connection refused
etcd-0               Healthy     {"health":"true"}

解决方法：

出现这种情况，是/etc/kubernetes/manifests下的kube-controller-manager.yaml和kube-scheduler.yaml设置的默认端口是0，在文件中注释掉就可以了

kube-controller-manager.yaml文件修改：注释掉27行

 1 apiVersion: v1
  2 kind: Pod
  3 metadata:
  4   creationTimestamp: null
  5   labels:
  6     component: kube-controller-manager
  7     tier: control-plane
  8   name: kube-controller-manager
  9   namespace: kube-system
 10 spec:
 11   containers:
 12   - command:
 13     - kube-controller-manager
 14     - --allocate-node-cidrs=true
 15     - --authentication-kubeconfig=/etc/kubernetes/controller-manager.conf
 16     - --authorization-kubeconfig=/etc/kubernetes/controller-manager.conf
 17     - --bind-address=127.0.0.1
 18     - --client-ca-file=/etc/kubernetes/pki/ca.crt
 19     - --cluster-cidr=10.244.0.0/16
 20     - --cluster-name=kubernetes
 21     - --cluster-signing-cert-file=/etc/kubernetes/pki/ca.crt
 22     - --cluster-signing-key-file=/etc/kubernetes/pki/ca.key
 23     - --controllers=*,bootstrapsigner,tokencleaner
 24     - --kubeconfig=/etc/kubernetes/controller-manager.conf
 25     - --leader-elect=true
 26     - --node-cidr-mask-size=24
 27   #  - --port=0
 28     - --requestheader-client-ca-file=/etc/kubernetes/pki/front-proxy-ca.crt
 29     - --root-ca-file=/etc/kubernetes/pki/ca.crt
 30     - --service-account-private-key-file=/etc/kubernetes/pki/sa.key
 31     - --service-cluster-ip-range=10.1.0.0/16
 32     - --use-service-account-credentials=true

kube-scheduler.yaml配置修改：注释掉19行

   

 1 apiVersion: v1
  2 kind: Pod
  3 metadata:
  4   creationTimestamp: null
  5   labels:
  6     component: kube-scheduler
  7     tier: control-plane
  8   name: kube-scheduler
  9   namespace: kube-system
 10 spec:
 11   containers:
 12   - command:
 13     - kube-scheduler
 14     - --authentication-kubeconfig=/etc/kubernetes/scheduler.conf
 15     - --authorization-kubeconfig=/etc/kubernetes/scheduler.conf
 16     - --bind-address=127.0.0.1
 17     - --kubeconfig=/etc/kubernetes/scheduler.conf
 18     - --leader-elect=true
 19   #  - --port=0

然后三台机器均重启kubelet     systemctl restart kubelet.service

再次查看 kubectl get cs

6. k8s集群拉取镜像仓库报错  

 Failed to pull image "registry-vpc.cn-beijing.aliyuncs.com/sjwd/wenduedu:platform-center-latest": rpc error: code = Unknown desc = Error response from daemon: pull access denied for registry-vpc.cn-beijing.aliyuncs.com/sjwd/wenduedu, repository does not exist

解决办法 （1）创建secret  

                    kubectl create secret docker-registry wenduedu --docker-server=registry-vpc.cn-beijing.aliyuncs.com/sjwd/wenduedu --docker-username=liruixin@wendu --docker-password=Wendu@2020 --docker-email=liruixin@wendu.com

                (2) yaml文件添加  

                    

    spec:
      imagePullSecrets:
        - name: wenduedu
      containers:
      - name: java-center
        image: registry-vpc.cn-beijing.aliyuncs.com/sjwd/wenduedu:platform-center-latest