执行kubeadm init报错

报错内容，如：

[kubelet-check] The HTTP call equal to ‘curl -sSL http://localhost:10248/healthz’ failed with error: Get “http://localhost:10248/healthz”: dial tcp [::1]:10248: connect: connection refused.

错误分析：journalctl -xeu kubelet，查看fail内容

journalctl -xeu kubelet | grep fail

原因分析：
1、swap分区未关闭
2、缺少/etc/systemd/system/kubelet.service.d/10-kubeadm.conf

# Environment="KUBELET_SYSTEM_PODS_ARGS=--pod-manifest-path=/etc/kubernetes/manifests --allow-privileged=true --fail-swap-on=false"
# Note: This dropin only works with kubeadm and kubelet v1.11+
[Service]
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、从节点上是否有docker镜像运行，可以在node节点上添加一个镜像并运行，如下：

docker pull redis && docker run -d -p 6379 --name myredis redis

4、在/etc/kubernetes下有manifests文件夹，需删除
rm -rf manifests/

以上执行后需要重新启动kubelet

systemctl daemon-reload && systemctl restart kubelet

报错[ERROR Swap]

解决：swapoff -a && sed -ri ‘s/.swap./#&/’ /etc/fstab

报错[ERROR FileContent–proc-sys-net-bridge-bridge-nf-call-iptables]

解决：

echo "1" >/proc/sys/net/bridge/bridge-nf-call-iptables

默认token有效期为24小时，当过期之后，该token就不可用了。这时就需要重新创建token，操作如下：

$ kubeadm token create
$ kubeadm token list
$ openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed 's/^.* //'
63bca849e0e01691ae14eab449570284f0c3ddeea590f8da988c07fe2729e924

$ kubeadm join 192.168.31.61:6443 --token nuja6n.o3jrhsffiqs9swnu --discovery-token-ca-cert-hash sha256:63bca849e0e01691ae14eab449570284f0c3ddeea590f8da988c07fe2729e924

或者直接命令快捷生成：kubeadm token create --print-join-command

附言

在实际工作中，看到有许多人，有的甚至是工作好多年的技术人员，处理问题时，都是盲目听信网上建议。在此，建议大家在出现问题时，应尽量阅读报错信息及查阅返回状态码，还有后面的处理建议。在此基础上锁定问题，再寻找解决方法，切勿根据只言片语，从网上盲目找方法去执行代码，解决问题。以免造成更大的生产问题，或隐藏的遗留问题。一定要树立正确的处理问题的方法。