K8s - 解決主機重啟后kubelet無法自動啟動問題 錯誤：The connection to the server 192.168.60.128:6443 was refused - did you specify the right host or port?

1，問題描述

（1）在安裝配置好 Kubernetes 后，正常情況下服務器關機重啟，kubelet 也會自動啟動的。但最近配置的一台服務器重啟后，輸入命令 kubectl get nodes 查看節點報如下錯誤：

The connection to the server 192.168.60.128:6443 was refused - did you specify the right host or port?

（2）輸入 systemctl status kubelet 命令查看 kubelet 的情況，發現 kubelet 確實沒有啟動：

ube-apiserver.service - Kubernetes API Server
   Loaded: loaded (/usr/lib/systemd/system/kube-apiserver.service; enabled; vendor preset: disabled)
   Active: failed (Result: start-limit) since Mon 2019-03-18 14:55:11 CST; 9min ago
     Docs: https://github.com/kubernetes/kubernetes
  Process: 6446 ExecStart=/opt/kubernetes/bin/kube-apiserver $KUBE_APISERVER_OPTS (code=exited, status=1/FAILURE)
 Main PID: 6446 (code=exited, status=1/FAILURE)

Mar 18 14:55:11 localhost.localdomain kube-apiserver[6446]: --vmodule moduleSpec                                      comma-separated list of pattern=N settings for file-filtered logging
Mar 18 14:55:11 localhost.localdomain kube-apiserver[6446]: --watch-cache                                             Enable watch caching in the apiserver (default true)
Mar 18 14:55:11 localhost.localdomain kube-apiserver[6446]: --watch-cache-sizes strings                               List of watch cache sizes for every resource (pods, nodes, etc.), comma sepa...ber. It take
Mar 18 14:55:11 localhost.localdomain kube-apiserver[6446]: error: failed to create listener: failed to listen on 192.168.60.128:6443: listen tcp 192.168.247.211:6443: bind: cannot assign requested address
Mar 18 14:55:11 master systemd[1]: kube-apiserver.service holdoff time over, scheduling restart.
Mar 18 14:55:11 master systemd[1]: Stopped Kubernetes API Server.
Mar 18 14:55:11 master systemd[1]: start request repeated too quickly for kube-apiserver.service
Mar 18 14:55:11 master systemd[1]: Failed to start Kubernetes API Server.
Mar 18 14:55:11 master systemd[1]: Unit kube-apiserver.service entered failed state.
Mar 18 14:55:11 master systemd[1]: kube-apiserver.service failed.
Hint: Some lines were ellipsized, use -l to show in full.

2，問題原因

    由於 K8s 必須保持全程關閉交換內存，之前我安裝是只是使用 swapoff -a 命令暫時關閉 swap。而機器重啟后，swap 還是會自動啟用，從而導致 kubelet 無法啟動。

3，解決辦法

（1）首先執行如下命令關閉 swap。

swapoff -a

（2）接着編輯 /etc/fstab 文件。

vi /etc/fstab

(3）將 /dev/mapper/centos-swap swap swap default 0 0 這一行前面加個 # 號將其注釋掉。

(4)  編輯完畢后保存退出。這樣機器重啟后 kubelet 也可以正常自動啟動了。

 

轉載：https://www.hangge.com/blog/cache/detail_2419.html