kubeadm init 或 join 失败 [kubelet-check] Initial timeout of 40s passed.

前言

kubeadm 初始化或 join 时，报错：

[etcd] Creating static Pod manifest for local etcd in "/etc/kubernetes/manifests"
I1122 10:50:39.224341   51720 local.go:65] [etcd] wrote Static Pod manifest for a local etcd member to "/etc/kubernetes/manifests/etcd.yaml"
I1122 10:50:39.224602   51720 waitcontrolplane.go:91] [wait-control-plane] Waiting for the API server to be healthy
[wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory "/etc/kubernetes/manifests". This can take up to 4m0s
[kubelet-check] Initial timeout of 40s passed.

	Unfortunately, an error has occurred:
		timed out waiting for the condition

	This error is likely caused by:
		- The kubelet is not running
		- The kubelet is unhealthy due to a misconfiguration of the node in some way (required cgroups disabled)

	If you are on a systemd-powered system, you can try to troubleshoot the error with the following commands:
		- 'systemctl status kubelet'
		- 'journalctl -xeu kubelet'

	Additionally, a control plane component may have crashed or exited when started by the container runtime.
	To troubleshoot, list all containers using your preferred container runtimes CLI.

	Here is one example how you may list all Kubernetes containers running in docker:
		- 'docker ps -a | grep kube | grep -v pause'
		Once you have found the failing container, you can inspect its logs with:
		- 'docker logs CONTAINERID'

couldn't initialize a Kubernetes cluster
k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases/init.runWaitControlPlanePhase
	/workspace/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases/init/waitcontrolplane.go:118
k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases/workflow.(*Runner).Run.func1
	/workspace/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases/workflow/runner.go:234
k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases/workflow.(*Runner).visitAll
	/workspace/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases/workflow/runner.go:421
k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases/workflow.(*Runner).Run

解决

新增 /etc/systemd/system/kubelet.service.d/10-kubeadm.conf文件，增加如下内容

vim /etc/systemd/system/kubelet.service.d/10-kubeadm.conf

# 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/sysconfig/kubelet
ExecStart=
ExecStart=/usr/bin/kubelet $KUBELET_KUBECONFIG_ARGS $KUBELET_CONFIG_ARGS $KUBELET_KUBEADM_ARGS $KUBELET_EXTRA_ARGS

https://raw.githubusercontent.com/kubernetes/release/v0.15.1/cmd/kubepkg/templates/latest/rpm/kubeadm/10-kubeadm.conf

重新init、join

删除初始化中断创建的文件

systemctl stop kubelet
kubeadm reset -f
rm -rf $HOME/.kube/config

rm -rf /etc/kubernetes
rm -rf /var/lib/etcd
rm -rf /var/lib/kubelet
rm -rf /var/lib/kubernetes

rm -rf /etc/systemd/system/kubelet.service.d
rm -rf /etc/systemd/system/kubelet.service
systemctl daemon-reload

rm -rf /etc/kubernetes/manifests

然后重新 init、join，就成功了

第二种解决方式

修改 /lib/systemd/system/kubelet.service文件

vim /lib/systemd/system/kubelet.service

添加 kubelet 启动参数，如下

[Service]
ExecStart=/usr/bin/kubelet --kubeconfig=/etc/kubernetes/kubelet.conf --config=/var/lib/kubelet/config.yaml

如有需要重启 kubelet，如下

systemctl daemon-reload
systemctl restat kubelet
systemctl status kubelet