K8s Master节点初始化失败求助：连接拒绝与Kubelet异常

问题根源分析 #

从日志可见两个核心问题：

1. kubelet启动失败，报错unable to load bootstrap kubeconfig: stat /etc/kubernetes/bootstrap-kubelet.conf: no such file or directory——该文件由kubeadm init生成，但kubelet提前启动时无法找到它，同时你的10-kubeadm.conf存在配置语法错误和重复参数问题。
2. apiserver 6443端口连接拒绝——依赖kubelet的核心组件（如apiserver、etcd）未正常启动，根源是kubelet异常。

解决步骤 #

1. 清理初始化残留

彻底清理未完成的初始化环境，避免残留文件干扰：

kubeadm reset -f
rm -rf /etc/kubernetes/
rm -rf /var/lib/kubelet/
systemctl stop kubelet containerd

2. 修正kubelet配置文件

编辑/etc/systemd/system/kubelet.service.d/10-kubeadm.conf，修正以下问题：

• 取消注释KUBELET_CONFIG_ARGS行，移除重复的容器运行时参数（避免和KUBELET_CGROUP_ARGS冲突）
• 修复KUBELET_KUBECONFIG_ARGS行的语法错误（原行末尾直接拼接注释，导致环境变量解析失败）

修正后的完整配置：

# Note: This dropin only works with kubeadm and kubelet v1.11+
[Service]
Environment="KUBELET_CGROUP_ARGS=--cgroup-driver=systemd --container-runtime=remote --container-runtime-endpoint=unix:///run/containerd/containerd.sock"
Environment="KUBELET_KUBECONFIG_ARGS=--bootstrap-kubeconfig=/etc/kubernetes/bootstrap-kubelet.conf --kubeconfig=/etc/kubernetes/kubelet.conf"
Environment="KUBELET_CONFIG_ARGS=--config=/var/lib/kubelet/config.yaml"
# This is a file that "kubeadm init" and "kubeadm join" generates at runtime, populating the KUBELET_KUBEADM_ARGS variable dynamically
EnvironmentFile=-/var/lib/kubelet/kubeadm-flags.env
# This is a file that the user can use for overrides of the kubelet args as a last resort. Preferably, the user should use
# the .NodeRegistration.KubeletExtraArgs object in the configuration files instead. KUBELET_EXTRA_ARGS should be sourced from this file.
EnvironmentFile=-/etc/default/kubelet
ExecStart=
ExecStart=/usr/bin/kubelet $KUBELET_KUBECONFIG_ARGS $KUBELET_CONFIG_ARGS $KUBELET_KUBEADM_ARGS $KUBELET_EXTRA_ARGS

3. 重启相关服务并重载配置

systemctl daemon-reload
systemctl restart containerd
systemctl enable containerd
systemctl enable kubelet --now

4. 重新执行kubeadm初始化

kubeadm init --apiserver-advertise-address 172.21.103.8 --pod-network-cidr 10.244.0.0/16 --image-repository registry.cn-hangzhou.aliyuncs.com/google_containers --v=9

5. 配置kubectl客户端

初始化成功后，执行以下命令配置本地kubectl：

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

验证检查 #

• 确认containerd的cgroup驱动设置：

  containerd config dump | grep SystemdCgroup
  

  输出应为SystemdCgroup = true
• 检查kubelet状态：

  systemctl status kubelet
  

  确保服务处于active(running)状态
• 检查核心组件容器运行状态：

  crictl ps
  

  确认kube-apiserver、kube-controller-manager、kube-scheduler、etcd容器正常运行

内容的提问来源于stack exchange，提问作者Yinfei