在 Kubernetes 集群中获取节点时出错连接被拒绝错误

问题描述

我在从 master 获取我的 kubernetes 集群的节点时收到连接被拒绝的错误。我已经尝试了互联网上所有可用的调试方法，但似乎没有一个有效。我的集群中有 1 个主节点和 2 个工作节点。

kubectl 获取节点

master@master-vm:~$ kubectl get nodes
The connection to the server X.X.X.X:6443 was refused - did you specify the right host or port?
master@master-vm:~$

Kubelet 状态

master@master-vm:~/.kube$ systemctl status kubelet
Active: active (running) since Tue 2021-03-16 19:53:33 IST; 20s ago
kubelet.go:2263] node "master-vm" not found

Docker 状态

master@master-vm:~$ systemctl status docker
 ● docker.service - Docker Application Container Engine
Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
Active: active (running) since Tue 2021-03-16 19:37:59 IST;

netstat 中的 6443 端口详细信息

master@master-vm:~$ sudo netstat -pnlt | grep 6443
[sudo] password for master:
tcp6      76      0 :::6443                 :::*                    LISTEN      1107/kube-apiserver
master@master-vm:~$

交换已关闭

master@master-vm:~$ sudo swapoff -a
master@master-vm:~$ free -m
              total        used        free      shared  buff/cache   available
Mem:           3936        1159        1468          11        1307        2545
Swap:             0           0           0
master@master-vm:~$

Kubectl 版本

master@master-vm:~$ kubectl version
Client Version: version.Info{Major:"1",Minor:"17",GitVersion:"v1.17.4",GitCommit:"8d8aa39598534325ad77120c120a22b3a990b5ea",GitTreeState:"clean",BuildDate:"2020-03-12T21:03:42Z",GoVersion:"go1.13.8",Compiler:"gc",Platform:"linux/amd64"}

The connection to the server X.X.X.X:6443 was refused - did you specify the right host or port?
master@master-vm:~$

防火墙状态

master@master-vm:~$ sudo ufw status verbose #ubuntu
Status: inactive
master@master-vm:~$ sudo ufw disable #ubuntu
Firewall stopped and disabled on system startup
master@master-vm:~$

/etc/hosts

127.0.0.1       localhost
127.0.1.1       master-vm

Kubeadm 版本

 master@master-vm:~$ kubeadm version
 kubeadm version: &version.Info{Major:"1",BuildDate:"2020-03-12T21:01:11Z",Platform:"linux/amd64"}
 master@master-vm:~$

Kubectl 配置视图

 master@master-vm:~/.kube$ kubectl config view
 apiVersion: v1
 clusters:
   cluster:
     certificate-authority-data: DATA+OMITTED
     server: https://X.X.X.X:6443
   name: kubernetes
 contexts:
   context:
     cluster: kubernetes
     user: kubernetes-admin
   name: kubernetes-admin@kubernetes
 current-context: kubernetes-admin@kubernetes
 kind: Config
 preferences: {}
 users:
   name: kubernetes-admin
   user:
     client-certificate-data: REDACTED
     client-key-data: REDACTED
 master@master-vm:~/

关于如何纠正上述错误的任何建议？

解决方法

在我看来，api 服务器运行在 ipv6 上（注意 netstat 输出中的 tcp6）。

尝试使用

启动您的 k8s

kubeadm init --apiserver-advertise-address=<private-ipv4 of master host>

--apiserver-advertise-address - API 服务器将通告它正在侦听的 IP 地址。如果未设置，将使用默认网络接口。

如果这没有帮助，您可能需要查看 api-server 日志。使用 docker logs 获取日志或：

cat /var/log/pods/kube-system_kube-apiserver-master-vm_xxxxxxx/kube-apiserver/0.log

尝试在主节点上执行以下代码行。

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

接下来尝试在同一个主节点上执行 kubectl get nodes，它应该可以正常工作。

docker docker kubeadm kubectl kubernetes