K8S集群部署过程耗时：不到1小时。

经过最近几次的k8s部署操作，自己也是踩过很多坑，总结记录一下详细、完整的部署过程，供对Kubernetes感兴趣的朋友参考，一起学习；

本次使用的3台2C4G的ECS百度云服务器，确保可以相互访问，如果跨VPC，可以建立“对等连接”：

主机名	IP	角色	操作系统
k8s-master	192.168.16.4	master	CentOS Linux 7.9
k8s-node01	192.168.16.5	node-01	CentOS Linux 7.9
k8s-node02	172.17.22.4	node-02	CentOS Linux 7.9

一、Kubernetes安装准备

全部节点执行：

1、关闭 SELinux 

## 临时并永久关闭SELinux
setenforce 0 && sed -i 's/^SELINUX=.*/SELINUX=disabled/' /etc/selinux/config

2、关闭防火墙

## 临时并永久关闭防火墙
systemctl stop firewalld && systemctl disable firewalld

3、关闭SWAP

# 1、临时并永久关闭交换空间
swapoff -a &&  sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab 

# 2、查看是否关闭成功
free -m

4、修改名hosts文件（/etc/hosts）

cat  >> /etc/hosts << EOF
192.168.16.4 k8s-master
192.168.16.5 k8s-node01
172.17.22.4 k8s-node02
EOF

5、配置ECS云服务器的主机名

# 在各自对应的主机上执行对应操作
hostnamectl set-hostname k8s-master
hostnamectl set-hostname k8s-node01
hostnamectl set-hostname k8s-node02

二、安装 Docker 服务

1、卸载旧版本

yum remove docker \
           docker-client \
           docker-client-latest \
           docker-common \
           docker-latest \
           docker-latest-logrotate \
           docker-logrotate \
           docker-engine

2、安装依赖包

yum install -y yum-utils

3、设置镜像仓库

Docker默认的国外官方镜像库拉取会非常慢，建议改用国内阿里云地址

yum-config-manager \
    --add-repo \
    http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo   #地址为国内阿里云地址

4、更新YUM索引

yum makecache

5、安装 Docker

直接安装最新版

#docker-ce 表示社区版，ee 表示企业版，默认安装最新版
yum -y install docker-ce docker-ce-cli containerd.io 

6、启动Docker

systemctl start docker
systemctl enable docker #设置开机启动

7、查看信息

1、查看Docker 启动版本
docker version
​
# 2、查看信息
docker info
​
# 3、测试docker 服务
docker run hello-world

在K8S中建议Docker与K8S使用的Cgroupdriver值为 “systemd”，所以每一个节点还需要进行如下的修改 ：

## Create /etc/docker directory.
mkdir /etc/docker

# Setup daemon.
cat > /etc/docker/daemon.json <<EOF
{
  "exec-opts": ["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m"
  },
  "storage-driver": "overlay2",
  "storage-opts": [
    "overlay2.override_kernel_check=true"
  ]
}
EOF

mkdir -p /etc/systemd/system/docker.service.d

# Restart Docker
systemctl daemon-reload
systemctl restart docker

三、安装 Kubernetes 必备工具

#1、配置YUM源
cat << EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=0
EOF

# 2、所有节点安装必备工具，版本不加默认为最新版，也可以指定版本号
yum  -y  install kubelet kubeadm kubectl --disableexcludes=kubernetes（用自定义的Kubernetes）

# 3、启动服务（设置系统重启后自动启动）
systemctl enable kubelet 

# 4、查看版本
kubeadm version              #kubeadm版本号
kubelet --version            #kubelet版本号
kubectl version              #kubectl版本号

四、创建配置文件信息、初始化Master节点

1、创建集群目录并进入
mkdir -p /usr/local/kubernetes/cluster 
cd /usr/local/kubernetes/cluster

# 2、导出配置文件
kubeadm config print init-defaults --kubeconfig ClusterConfiguration > kubeadm.yml

# 3、备份并修改导出的配置文件，修改内容如下
[root@k8s-master cluster]# cp kubeadm.yml kubeadm.yml-bak
[root@k8s-master cluster]# cat kubeadm.yml
apiVersion: kubeadm.k8s.io/v1beta3
bootstrapTokens:
- groups:
  - system:bootstrappers:kubeadm:default-node-token
  token: abcdef.0123456789abcdef
  ttl: 24h0m0s
  usages:
  - signing
  - authentication
kind: InitConfiguration
localAPIEndpoint:
  advertiseAddress: 192.168.16.4    #######修改一： 修改为主节点IP为maser的实际IP，默认配置为1.2.3.4
  bindPort: 6443
nodeRegistration:
  criSocket: /var/run/dockershim.sock
  imagePullPolicy: IfNotPresent
  name: k8s-master    #######修改二： 修改为主节点k8s-maser
  taints: null
---
apiServer:
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta3
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager: {}
dns: {}
etcd:
  local:
    dataDir: /var/lib/etcd
imageRepository: registry.aliyuncs.com/google_containers  #######修改三： 修改镜像下载地址为阿里云地址，默认为国外下载地址：k8s.gcr.io
kind: ClusterConfiguration
kubernetesVersion: 1.23.6   #######修改四：修改为Kubernetes实际安装版本，否则服务起不来。查看版本命名kubeadm version
networking:
  dnsDomain: cluster.local
  podSubnet: "10.244.0.0/16"  #######修改五：配置Pod所在网段为我们虚拟机不冲突的网段（这里用的是Flannel默认网段），默认配置为：podSubnet: ""
  serviceSubnet: 10.96.0.0/12
scheduler: {}

初始化主节点

[root@k8s-master cluster]# kubeadm init --config=kubeadm.yml --upload-certs | tee kubeadm-init.log
###########以下为输出信息，内容同步到kubeadm-init.log日志里，方便后续查看内容信息
[root@k8s-master cluster]# kubeadm init --config=kubeadm.yml --upload-certs | tee kubeadm-init.log
[init] Using Kubernetes version: v1.23.6
[preflight] Running pre-flight checks
[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"
[certs] Generating "ca" certificate and key
[certs] Generating "apiserver" certificate and key
[certs] apiserver serving cert is signed for DNS names [k8s-master kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 192.168.16.4]
[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 [k8s-master localhost] and IPs [192.168.16.4 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [k8s-master localhost] and IPs [192.168.16.4 127.0.0.1 ::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
[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
[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"
[control-plane] Creating static Pod manifest for "kube-scheduler"
[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
[apiclient] All control plane components are healthy after 7.003639 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.23" in namespace kube-system with the configuration for the kubelets in the cluster
NOTE: The "kubelet-config-1.23" naming of the kubelet ConfigMap is deprecated. Once the UnversionedKubeletConfigMap feature gate graduates to Beta the default name will become just "kubelet-config". Kubeadm upgrade will handle this transition transparently.
[upload-certs] Storing the certificates in Secret "kubeadm-certs" in the "kube-system" Namespace
[upload-certs] Using certificate key:
59431c553915b0d1c83bbf63db5ab840973aeae000bf4b2a9453931913a7d9f0
[mark-control-plane] Marking the node k8s-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]
[mark-control-plane] Marking the node k8s-master as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: abcdef.0123456789abcdef
[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

Alternatively, if you are the root user, you can run:

  export KUBECONFIG=/etc/kubernetes/admin.conf

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 192.168.16.4:6443 --token abcdef.0123456789abcdef \
        --discovery-token-ca-cert-hash sha256:cc7a93795871aa97b47dda0d8cbc18d19577245b40e6068f1f4aaebb9b40e6b4
[root@k8s-master cluster]#
[root@k8s-master cluster]#
[root@k8s-master cluster]#
[root@k8s-master cluster]#mkdir -p $HOME/.kube
[root@k8s-master cluster]#sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config

查看节点信息

root@k8s-master cluster]# kubectl get nodes
NAME           STATUS     ROLES    AGE     VERSION
k8s-master01   NotReady   master   6m10s   v1.14.0

# NotReady 是因为还没有配置网络插件，需要网络插件，如Flannel

添加 Flannel 网络插件

其中需要在master节点和全部node节点都安装flannel插件

# 1、下载资源配置清单
wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

# 2、运行资源清单
kubectl apply -f kube-flannel.yml 

# 3、再次查看状态信息（STATUS 状态变成 Ready）
kubectl get nodes

# 输出如下：
[root@k8s-master cluster]# kubectl get nodes
NAME         STATUS   ROLES                  AGE     VERSION
k8s-master   Ready    control-plane,master   6m15s   v1.23.6


# 4、查看网卡，发现多处一个 flannel.1: 网卡
ifconfig 

从节点加入主节点

在k8s-node01,k8s-node02节点上执行：

# 验证信息从主节点初始化日志里面查找
kubeadm join 192.168.16.4:6443 --token abcdef.0123456789abcdef \
        --discovery-token-ca-cert-hash sha256:cc7a93795871aa97b47dda0d8cbc18d19577245b40e6068f1f4aaebb9b40e6b4

    
## 以下为输出信息
[root@k8s-node01 docker]# kubeadm join 192.168.16.4:6443 --token abcdef.0123456789abcdef \
>         --discovery-token-ca-cert-hash sha256:cc7a93795871aa97b47dda0d8cbc18d19577245b40e6068f1f4aaebb9b40e6b4
[preflight] Running pre-flight checks
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -o yaml'
[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@k8s-node01 docker]#

[root@k8s-master cluster]# kubectl get nodes
NAME         STATUS   ROLES                  AGE    VERSION
k8s-master   Ready    control-plane,master   25m    v1.23.6
k8s-node01   Ready    <none>                 17m    v1.23.6
k8s-node02   Ready    <none>                 114s   v1.23.6

Kubernetes集群顺利搭建完成！

问题记录：

1、K8S Node节点报错The connection to the server localhost:8080 was refused - did you specify the right host or port?

出现这个问题的原因是kubectl命令需要使用kubernetes-admin来运行，解决方法如下，将主节点中的【/etc/kubernetes/admin.conf】文件拷贝到从节点相同目录下，然后配置环境变量：

echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> ~/.bash_profile

立即生效

source ~/.bash_profile

2、解决docker网络与宿主机网络冲突问题

vim /etc/docker/daemon.json（这里没有这个文件的话，自行创建）

{

"bip":"172.16.10.1/24"

}

[root@k8s-node02 docker]# vim daemon.json
[root@k8s-node02 docker]# systemctl daemon-reload
[root@k8s-node02 docker]# systemctl restart docker
[root@k8s-node02 docker]#

参考资料：https://www.cnblogs.com/wangzy-Zj/p/14078816.html