1. 全部node节点出现 Unable to read config path "/etc/kubernetes/manifests": path does not exist, ignoring

报错原因：未知

解决办法：创建一个空manifests

$ mkdir /etc/kubernetes/manifests

2. 所有的node节点不停的报“Scope libcontainer-12708-systemd-test-default-dependencies.scope has no PIDs. Refusing.”

报错原因：https://github.com/kubernetes/kubernetes/issues/76531

解决办法：根据github上大家的回答，初步判定是bug，将docker版本升级到18.09，k8s版本升级到1.16.3，该问题已被修复

3. kubectl get cs显示scheduler Unhealthy，controller-manager Unhealthy

通过kubeadm安装的k8s集群获取kube-scheduler和kube-controller-manager组件状态异常

$ kubectl get cs
NAME                 STATUS      MESSAGE                                                                                     ERROR
controller-manager   Unhealthy   Get http://127.0.0.1:10252/healthz: dial tcp 127.0.0.1:10252: connect: connection refused
scheduler            Unhealthy   Get http://127.0.0.1:10251/healthz: dial tcp 127.0.0.1:10251: connect: connection refused
etcd-0               Healthy     {"health":"true"}

kubernetes版本：v1.18.6

镜像信息

$ sudo docker images
REPOSITORY                           TAG                 IMAGE ID            CREATED             SIZE
nginx                                latest              8cf1bfb43ff5        4 hours ago         132MB
k8s.gcr.io/kube-proxy                v1.18.6             c3d62d6fe412        6 days ago          117MB
k8s.gcr.io/kube-apiserver            v1.18.6             56acd67ea15a        6 days ago          173MB
k8s.gcr.io/kube-controller-manager   v1.18.6             ffce5e64d915        6 days ago          162MB
k8s.gcr.io/kube-scheduler            v1.18.6             0e0972b2b5d1        6 days ago          95.3MB
quay.io/coreos/flannel               v0.12.0-amd64       4e9f801d2217        4 months ago        52.8MB
k8s.gcr.io/pause                     3.2                 80d28bedfe5d        5 months ago        683kB
k8s.gcr.io/coredns                   1.6.7               67da37a9a360        5 months ago        43.8MB
k8s.gcr.io/etcd                      3.4.3-0             303ce5db0e90        9 months ago        288MB

k8s组件pod状态

$ kubectl get pods -A
NAMESPACE     NAME                              READY   STATUS    RESTARTS   AGE
kube-system   coredns-66bff467f8-22hgp          1/1     Running   0          45m
kube-system   coredns-66bff467f8-ck6qq          1/1     Running   0          45m
kube-system   etcd-node-14                      1/1     Running   0          46m
kube-system   kube-apiserver-node-14            1/1     Running   0          46m
kube-system   kube-controller-manager-node-14   1/1     Running   0          17m
kube-system   kube-flannel-ds-amd64-lm7lt       1/1     Running   0          44m
kube-system   kube-proxy-5hghv                  1/1     Running   0          45m
kube-system   kube-scheduler-node-14            1/1     Running   0          17m

排查思路：

1、先查看本地的端口，可以确认没有启动10251、10252端口

2、确认kube-scheduler和kube-controller-manager组件配置是否禁用了非安全端口

配置文件路径：/etc/kubernetes/manifests/scheduler.conf 、/etc/kubernetes/manifests/controller-manager.conf

如controller-manager组件的配置如下：可以去掉--port=0这个设置，然后重启sudo systemctl restart kubelet

重启服务之后确认组件状态，显示就正常了

$ kubectl get cs
NAME                 STATUS    MESSAGE             ERROR
scheduler            Healthy   ok
controller-manager   Healthy   ok
etcd-0               Healthy   {"health":"true"}