K8s API Server的鉴权问题由来已久。默认情况下K8s API Server会开启两个端口：8080(Localhost Port)和 6443(Secure Port)，其中8080端口为WEB UI Dashboard，无需认证，用于本地测试与监控；6443端口需要认证且有TLS保护，用于远程连接(如：通过kubectl管理集群)。
root@ubuntu:~# kubectl label node bogon node-role.kubernetes.io/worker=worker Unable to connect to the server: dial tcp 10.10.16.82:6443: connect: network is unreachable root@ubuntu:~# systemctl status firewalld Unit firewalld.service could not be found. root@ubuntu:~#
root@ubuntu:~# kubeadm reset
root@ubuntu:~# kubeadm init --kubernetes-version=v1.18.1 --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=10.10.16.82 --image-repository registry.aliyuncs.com/google_containers W0618 18:47:56.560541 2512 configset.go:202] WARNING: kubeadm cannot validate component configs for API groups [kubelet.config.k8s.io kubeproxy.config.k8s.io] [init] Using Kubernetes version: v1.18.1 [preflight] Running pre-flight checks [WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/ error execution phase preflight: [preflight] Some fatal errors occurred: [ERROR FileContent--proc-sys-net-bridge-bridge-nf-call-iptables]: /proc/sys/net/bridge/bridge-nf-call-iptables does not exist [preflight] If you know what you are doing, you can make a check non-fatal with `--ignore-preflight-errors=...` To see the stack trace of this error execute with --v=5 or higher root@ubuntu:~# echo 1 > /proc/sys/net/bridge/bridge-nf-call-iptables -bash: /proc/sys/net/bridge/bridge-nf-call-iptables: No such file or directory
root@ubuntu:~# modprobe br_netfilter root@ubuntu:~# echo 1 > /proc/sys/net/bridge/bridge-nf-call-iptables -bash: /proc/sys/net/bridge/bridge-nf-call-iptables: No such file or directory root@ubuntu:~# ls /proc/sys/net/bridge ls: cannot access ‘/proc/sys/net/bridge‘: No such file or directory root@ubuntu:~#
reboot
root@ubuntu:~# kubectl get pods W0618 19:10:03.441191 5273 loader.go:223] Config not found: /etc/kubernetes/admin.conf error: no configuration has been provided, try setting KUBERNETES_MASTER environment variable root@ubuntu:~# kubeadm init --kubernetes-version=v1.18.1 --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=10.10.16.82 --image-repository registry.aliyuncs.com/google_containers W0618 19:10:25.620172 5382 configset.go:202] WARNING: kubeadm cannot validate component configs for API groups [kubelet.config.k8s.io kubeproxy.config.k8s.io] [init] Using Kubernetes version: v1.18.1 [preflight] Running pre-flight checks [WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/ [preflight] Pulling images required for setting up a Kubernetes cluster [preflight] This might take a minute or two, depending on the speed of your internet connection [preflight] You can also perform this action in beforehand using ‘kubeadm config images pull‘ error execution phase preflight: [preflight] Some fatal errors occurred: [ERROR ImagePull]: failed to pull image registry.aliyuncs.com/google_containers/kube-controller-manager:v1.18.1: output: Error response from daemon: Get https://registry.aliyuncs.com/v2/: dial tcp: lookup registry.aliyuncs.com: Temporary failure in name resolution , error: exit status 1 [preflight] If you know what you are doing, you can make a check non-fatal with `--ignore-preflight-errors=...` To see the stack trace of this error execute with --v=5 or higher root@ubuntu:~# kubeadm init --kubernetes-version=v1.18.1 --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=10.10.16.82 W0618 19:11:19.808717 6071 configset.go:202] WARNING: kubeadm cannot validate component configs for API groups [kubelet.config.k8s.io kubeproxy.config.k8s.io] [init] Using Kubernetes version: v1.18.1 [preflight] Running pre-flight checks [WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/ [preflight] Pulling images required for setting up a Kubernetes cluster [preflight] This might take a minute or two, depending on the speed of your internet connection [preflight] You can also perform this action in beforehand using ‘kubeadm config images pull‘ [kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env" [kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml" [kubelet-start] Starting the kubelet [certs] Using certificateDir folder "/etc/kubernetes/pki" [certs] Generating "ca" certificate and key [certs] Generating "apiserver" certificate and key [certs] apiserver serving cert is signed for DNS names [ubuntu kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 10.10.16.82] [certs] Generating "apiserver-kubelet-client" certificate and key [certs] Generating "front-proxy-ca" certificate and key [certs] Generating "front-proxy-client" certificate and key [certs] Generating "etcd/ca" certificate and key [certs] Generating "etcd/server" certificate and key [certs] etcd/server serving cert is signed for DNS names [ubuntu localhost] and IPs [10.10.16.82 127.0.0.1 ::1] [certs] Generating "etcd/peer" certificate and key [certs] etcd/peer serving cert is signed for DNS names [ubuntu localhost] and IPs [10.10.16.82 127.0.0.1 ::1] [certs] Generating "etcd/healthcheck-client" certificate and key [certs] Generating "apiserver-etcd-client" certificate and key [certs] Generating "sa" key and public key [kubeconfig] Using kubeconfig folder "/etc/kubernetes" [kubeconfig] Writing "admin.conf" kubeconfig file [kubeconfig] Writing "kubelet.conf" kubeconfig file [kubeconfig] Writing "controller-manager.conf" kubeconfig file [kubeconfig] Writing "scheduler.conf" kubeconfig file [control-plane] Using manifest folder "/etc/kubernetes/manifests" [control-plane] Creating static Pod manifest for "kube-apiserver" [control-plane] Creating static Pod manifest for "kube-controller-manager" W0618 19:11:29.919280 6071 manifests.go:225] the default kube-apiserver authorization-mode is "Node,RBAC"; using "Node,RBAC" [control-plane] Creating static Pod manifest for "kube-scheduler" W0618 19:11:29.921005 6071 manifests.go:225] the default kube-apiserver authorization-mode is "Node,RBAC"; using "Node,RBAC" [etcd] Creating static Pod manifest for local etcd in "/etc/kubernetes/manifests" [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. [apiclient] All control plane components are healthy after 64.003340 seconds [upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace [kubelet] Creating a ConfigMap "kubelet-config-1.18" in namespace kube-system with the configuration for the kubelets in the cluster [upload-certs] Skipping phase. Please see --upload-certs [mark-control-plane] Marking the node ubuntu as control-plane by adding the label "node-role.kubernetes.io/master=‘‘" [mark-control-plane] Marking the node ubuntu as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule] [bootstrap-token] Using token: qpqoq3.y2lo787xtima2xaz [bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles [bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to get nodes [bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials [bootstrap-token] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token [bootstrap-token] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster [bootstrap-token] Creating the "cluster-info" ConfigMap in the "kube-public" namespace [kubelet-finalize] Updating "/etc/kubernetes/kubelet.conf" to point to a rotatable kubelet client certificate and key [addons] Applied essential addon: CoreDNS [addons] Applied essential addon: kube-proxy Your Kubernetes control-plane has initialized successfully! To start using your cluster, you need to run the following as a regular user: mkdir -p $HOME/.kube sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config sudo chown $(id -u):$(id -g) $HOME/.kube/config You should now deploy a pod network to the cluster. Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at: https://kubernetes.io/docs/concepts/cluster-administration/addons/ Then you can join any number of worker nodes by running the following on each as root: kubeadm join 10.10.16.82:6443 --token qpqoq3.y2lo787xtima2xaz --discovery-token-ca-cert-hash sha256:374990d65ea0b1dd227fe68aa994fa16439d0ddf99735642eee6116d98e1b829 root@ubuntu:~# kubectl get pods No resources found in default namespace. root@ubuntu:~# kubectl get nodes NAME STATUS ROLES AGE VERSION ubuntu Ready master 28s v1.18.1 root@ubuntu:~#
root@cloud:~# kubeadm join 10.10.16.82:6443 --token qpqoq3.y2lo787xtima2xaz > --discovery-token-ca-cert-hash sha256:374990d65ea0b1dd227fe68aa994fa16439d0ddf99735642eee6116d98e1b829 W0618 19:13:12.330177 424863 join.go:346] [preflight] WARNING: JoinControlPane.controlPlane settings will be ignored when control-plane flag is not set. [preflight] Running pre-flight checks [WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/ error execution phase preflight: [preflight] Some fatal errors occurred: [ERROR FileAvailable--etc-kubernetes-kubelet.conf]: /etc/kubernetes/kubelet.conf already exists [ERROR Port-10250]: Port 10250 is in use [ERROR FileAvailable--etc-kubernetes-pki-ca.crt]: /etc/kubernetes/pki/ca.crt already exists [preflight] If you know what you are doing, you can make a check non-fatal with `--ignore-preflight-errors=...` To see the stack trace of this error execute with --v=5 or higher root@cloud:~# kubeadm -f unknown shorthand flag: ‘f‘ in -f To see the stack trace of this error execute with --v=5 or higher root@cloud:~# kubeadm reset -f [preflight] Running pre-flight checks W0618 19:13:48.230061 425763 removeetcdmember.go:79] [reset] No kubeadm config, using etcd pod spec to get data directory [reset] No etcd config found. Assuming external etcd [reset] Please, manually reset etcd to prevent further issues [reset] Stopping the kubelet service [reset] Unmounting mounted directories in "/var/lib/kubelet" [reset] Deleting contents of config directories: [/etc/kubernetes/manifests /etc/kubernetes/pki] [reset] Deleting files: [/etc/kubernetes/admin.conf /etc/kubernetes/kubelet.conf /etc/kubernetes/bootstrap-kubelet.conf /etc/kubernetes/controller-manager.conf /etc/kubernetes/scheduler.conf] [reset] Deleting contents of stateful directories: [/var/lib/kubelet /var/lib/dockershim /var/run/kubernetes /var/lib/cni] The reset process does not clean CNI configuration. To do so, you must remove /etc/cni/net.d The reset process does not reset or clean up iptables rules or IPVS tables. If you wish to reset iptables, you must do so manually by using the "iptables" command. If your cluster was setup to utilize IPVS, run ipvsadm --clear (or similar) to reset your system‘s IPVS tables. The reset process does not clean your kubeconfig files and you must remove them manually. Please, check the contents of the $HOME/.kube/config file. root@cloud:~# rm -rf /etc/cni/net.d root@cloud:~# kubeadm join 10.10.16.82:6443 --token qpqoq3.y2lo787xtima2xaz --discovery-token-ca-cert-hash sha256:374990d65ea0b1dd227fe68aa994fa16439d0ddf99735642eee6116d98e1b829 W0618 19:15:43.669891 426976 join.go:346] [preflight] WARNING: JoinControlPane.controlPlane settings will be ignored when control-plane flag is not set. [preflight] Running pre-flight checks [WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/ [preflight] Reading configuration from the cluster... [preflight] FYI: You can look at this config file with ‘kubectl -n kube-system get cm kubeadm-config -oyaml‘ [kubelet-start] Downloading configuration for the kubelet from the "kubelet-config-1.18" ConfigMap in the kube-system namespace [kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml" [kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env" [kubelet-start] Starting the kubelet [kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap... This node has joined the cluster: * Certificate signing request was sent to apiserver and a response was received. * The Kubelet was informed of the new secure connection details. Run ‘kubectl get nodes‘ on the control-plane to see this node join the cluster. root@cloud:~#
root@ubuntu:~# kubectl get nodes NAME STATUS ROLES AGE VERSION bogon NotReady <none> 8s v1.18.1 cloud Ready <none> 2m37s v1.21.1 ubuntu Ready master 5m58s v1.18.1 root@ubuntu:~# kubectl get nodes NAME STATUS ROLES AGE VERSION bogon Ready <none> 10s v1.18.1 cloud Ready <none> 2m39s v1.21.1 ubuntu Ready master 6m v1.18.1 root@ubuntu:~# kubectl get nodes
MASTER端+NODE共同服务 systemctl restart etcd systemctl daemon-reload systemctl enable flanneld systemctl restart flanneld MASTER端独有服务 systemctl daemon-reload systemctl enable kube-apiserver systemctl restart kube-apiserver systemctl daemon-reload systemctl enable kube-controller-manager systemctl restart kube-controller-manager systemctl daemon-reload systemctl enable kube-scheduler systemctl restart kube-scheduler NODE端独有服务 systemctl daemon-reload systemctl enable kubelet systemctl restart kubelet（status状态为 not ready时候重启即可） systemctl daemon-reload systemctl enable kube-proxy systemctl restart kube-proxy systemctl status etcd systemctl status flanneld systemctl status kube-apiserver systemctl status kube-controller-manager systemctl status kube-scheduler systemctl status kubelet systemctl status kube-proxy