前言：
kubernetes集群的部署工作是比较繁琐的，但kubeadm使得急速部署集群成为了一种可能，离线化的部署可以提高部署的效率，使得网络（各种镜像经常下载不了或者下载缓慢）不是部署工作的瓶颈。
OK，下面就讲解一哈如何利用kubeadm急速部署一个简单的可用于测试的kubernetes集群（如果对linux比较熟练的话，可以在5分钟内就部署完成）。
一，本次实践的服务器以及需要安装的组件的情况说明
计划使用三台VMware虚拟机做这个集群，当然，物理机也是一样的道理，在此就不啰嗦了。
二，先决条件：
A，时间服务器
时间服务器的用途就不多说了，必须要有的一个重要组件。
三个节点都执行命令：
yum install ntp -y && systemctl enable ntpd
19服务器的/etc/ntp.conf 配置文件内：
1. server 127.127.1.0 prefer 2. fudge 127.127.1.0 stratum 10
20和21服务器的/etc/ntp.conf配置文件内：
server 192.168.217.19
三台服务器都执行命令，以重启时间服务器：
systemctl restart ntpd
以上的配置表明以19服务器为主时间服务器，其它节点与此服务器时间同步，在工作节点上执行以下命令，输出为此，表示时间服务器正常：
[root@node2 ~]# ntpq -p remote refid st t when poll reach delay offset jitter ============================================================================== *master LOCAL(0) 11 u 50 256 377 0.517 0.024 0.076 [root@node2 ~]# ntpstat synchronised to NTP server (192.168.217.19) at stratum 12 time correct to within 25 ms polling server every 256 s
B，集群服务器的免 密码ssh
服务器之间的免密就不在此啰嗦了，实在是太基础的东西了。
C，集群服务器的防火墙关闭以及swap交换内存关闭，selinux关闭
关闭防火墙（三台服务器都执行）：
systemctl disable firewalld && systemctl stop firewalld
关闭swap交互内存：
swapoff -a
selinux的关闭就不说了，直接看测试结果，如下表示已关闭：
1. [root@node2 ~]# getenforce 2. Disabled
D，主机名的固定，三台服务器统一这个hosts
[root@node2 ~]# cat /etc/hosts 127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 192.168.217.19 master k8s-master 192.168.217.20 node1 k8s-node1 192.168.217.21 node2 k8s-node2
F，本地yum仓库以及基础软件
本地仓库的搭建见我的博客：Linux的完全本地仓库搭建指南（科普扫盲贴）_晚风_END的博客-CSDN博客_linux创建仓库
G：docker环境的搭建
docker环境的搭建见我的博客：docker的离线安装以及本地化配置_晚风_END的博客-CSDN博客
三，上传离线安装包到服务器内，离线安装包如下：
[root@master ~]# ll total 3016 -rw-r--r-- 1 root root 3069556 Oct 22 21:28 flannel #网络插件 drwxr-xr-x 3 root root 4096 Oct 22 21:10 k8s-offline-rpm #rpm安装包，这个需要挂载为仓库 drwxr-xr-x 2 root root 4096 Oct 22 21:11 kubeadin-offline-image #docker镜像 -rw-r--r-- 1 root root 4813 Oct 22 21:18 kube-flannel.yml #flannel的部署清单文件 #以上文件都放置在root目录下，node节点只需要前面三个，不需要kube-flannel.yml 文件
离线安装包下载链接：
链接：https://pan.baidu.com/s/1_vlzm3YMxOewIx2HaDOKJg?pwd=sdaa
提取码：sdaa
本地仓库的开启：
cat > /etc/yum.repos.d/k8s.repo <<EOF [k8s] name=k8s baseurl=file:///root/k8s-offline-rpm enable=1 gpgcheck=0 EOF
导入离线的docker镜像：
1. cd kubeadin-offline-image 2. for i in `ls /root/kubeadin-offline-image`;do docker load -i $i;done
赋予flannel插件的可执行权限：
chmod a+x flannel
安装相关软件：
yum install -y kubeadm-1.22.2 kubelet-1.22.2 kubectl-1.22.2 conntrack-tools libseccomp \ libtool-ltdl device-mapper-persistent-data lvm2
四，集群初始化以及工作节点加入
方式一----命令初始化：
因为前面yum下载的是1.22.2，因此，这里的版本也指定的是1.22.2，apiserver-advertise-address这里是master服务器的IP
kubeadm init \ --apiserver-advertise-address=192.168.217.19 \ --image-repository registry.aliyuncs.com/google_containers \ --kubernetes-version v1.22.2 \ --service-cidr=10.96.0.0/12 \ --pod-network-cidr=10.244.0.0/16
初始化命令的输出如下：
[init] Using Kubernetes version: v1.22.2 [preflight] Running pre-flight checks [WARNING Service-Kubelet]: kubelet service is not enabled, please run 'systemctl enable kubelet.service' [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' [certs] Using certificateDir folder "/etc/kubernetes/pki" #kubeadm自动生成相关证书 [certs] Generating "ca" certificate and key#kubeadm自动生成相关证书 [certs] Generating "apiserver" certificate and key#kubeadm自动生成相关证书 [certs] apiserver serving cert is signed for DNS names [kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local master] and IPs [10.96.0.1 192.168.217.19]#kubeadm自动生成相关证书，这里提示了DNS是10.96.0.1 [certs] Generating "apiserver-kubelet-client" certificate and key#kubeadm自动生成相关证书 [certs] Generating "front-proxy-ca" certificate and key#kubeadm自动生成相关证书 [certs] Generating "front-proxy-client" certificate and key#kubeadm自动生成相关证书 [certs] Generating "etcd/ca" certificate and key#kubeadm自动生成相关证书 [certs] Generating "etcd/server" certificate and key#kubeadm自动生成相关证书 [certs] etcd/server serving cert is signed for DNS names [localhost master] and IPs [192.168.217.19 127.0.0.1 ::1] [certs] Generating "etcd/peer" certificate and key#kubeadm自动生成相关证书，etcd的证书 [certs] etcd/peer serving cert is signed for DNS names [localhost master] and IPs [192.168.217.19 127.0.0.1 ::1]#kubeadm自动生成相关证书，etcd的证书 [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"#使用此目录下的配置文件 [kubeconfig] Writing "admin.conf" kubeconfig file#生成配置文件 [kubeconfig] Writing "kubelet.conf" kubeconfig file#生成kubelet的相关配置文件 [kubeconfig] Writing "controller-manager.conf" kubeconfig file#生成controller的配置文件 [kubeconfig] Writing "scheduler.conf" kubeconfig file#生成schedule的配置文件 [kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"#kubelet的配置文件 [kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"#还是kubelet的配置文件 [kubelet-start] Starting the kubelet#启动kubelet服务 [control-plane] Using manifest folder "/etc/kubernetes/manifests" [control-plane] Creating static Pod manifest for "kube-apiserver"#启动静态pod kube-apiserver [control-plane] Creating static Pod manifest for "kube-controller-manager"#启动静态pod controller-manager [control-plane] Creating static Pod manifest for "kube-scheduler"#启动静态pod [etcd] Creating static Pod manifest for local etcd in "/etc/kubernetes/manifests"#启动静态pod [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 [apiclient] All control plane components are healthy after 13.504364 seconds#健康检查完毕 [upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace#使用cm文件 [kubelet] Creating a ConfigMap "kubelet-config-1.22" in namespace kube-system with the configuration for the kubelets in the cluster#创建一个kubelet的cm [upload-certs] Skipping phase. Please see --upload-certs [mark-control-plane] Marking the node master as control-plane by adding the labels: [node-role.kubernetes.io/master(deprecated) node-role.kubernetes.io/control-plane node.kubernetes.io/exclude-from-external-load-balancers]#给节点打了标签 [mark-control-plane] Marking the node master as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule] #给master节点打了一个污点 [bootstrap-token] Using token: b1zldq.89t1aea8szja9d7l #token的使用 [bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles [bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to get nodes #rbac系统建立 [bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials#rbac系统建立 [bootstrap-token] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token #rbac系统建立 [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 #使用cm保存集群信息 [kubelet-finalize] Updating "/etc/kubernetes/kubelet.conf" to point to a rotatable kubelet client certificate and key #指定kubelet的证书 [addons] Applied essential addon: CoreDNS #部署组件coredns [addons] Applied essential addon: kube-proxy#部署组件kube-proxy Your Kubernetes control-plane has initialized successfully!#控制盘已经建立完成 To start using your cluster, you need to run the following as a regular user: mkdir -p $HOME/.kube#固化环境变量 sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config sudo chown $(id -u):$(id -g) $HOME/.kube/config Alternatively, if you are the root user, you can run: export KUBECONFIG=/etc/kubernetes/admin.conf#临时环境变量 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/ #建议你apply一个测试文件，做集群的测试工作 Then you can join any number of worker nodes by running the following on each as root: #工作节点加入命令 kubeadm join 192.168.217.19:6443 --token b1zldq.89t1aea8szja9d7l \ --discovery-token-ca-cert-hash sha256:6ac4ccaf392e4173b7fd9c09cebfd0e2d7eb5ff5a826f39409701fe012ad2ba4
