k8s搭建部署--三个节点服务器

docker环境准备

安装kubeadm,kubelet和kubectl

Centos添加kubernetes YUM软件源

ubuntu修改源

master主机执行

node节点执行

部署flannel

查看集群状态

测试

k8s搭建部署--三个节点服务器

#建议：先全部在一台master上执行完成集群的安装，最后node节点再加入集群

#硬件环境的要求：
cpu：2c
memory：4G/2G
#软件环境的要求：

# docker环境准备

准备4台虚拟机（centos，一台master，三台node）并运行以下脚本：

#!/bin/bash

#解决依赖关系

yum install -y yum-utils zlib zlib-devel openssl openssl-devel pcre pcre-devel gcc gcc-c++ autoconf automake make  psmisc  lsof  net-tools vim python3

#关闭防火墙

   systemctl stop  firewalldsystemctl disable  firewalld

#关闭selinux
setenforce 0 #临时关闭
#永久关闭
sed -i '/^SELINUX/ s/enforcing/disabled/' /etc/selinux/config

# 安装docker
## 卸载旧版本

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

docker版本

```
[root@k8s-master ~]# docker version
Client: Docker Engine - Community
Version: 20.10.8
API version: 1.41
Go version: go1.16.6
Git commit: 3967b7d
Built: Fri Jul 30 19:53:39 2021
OS/Arch: linux/amd64
Context: default
Experimental: true

Server: Docker Engine - Community
Engine:
Version: 20.10.8
API version: 1.41 (minimum version 1.12)
Go version: go1.16.6
```

## 安装yum-utils软件包（提供yum-config-manager 实用程序），配置加速源

yum install -y yum-utilsyum-config-manager \--add-repo \http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

## 安装docker,设置开机自启

 yum install -y docker-ce docker-ce-cli containerd.iosystemctl start dockersystemctl enable docker

## 配置 Docker使用systemd作为默认Cgroup驱动

每台服务器上都要操作，master和node上都要操作

 cat <<EOF > /etc/docker/daemon.json{"exec-opts": ["native.cgroupdriver=systemd"]}EOF

#重启docker
systemctl restart docker
## 关闭swap分区，每台服务器都需要操作

swapoff -a # 临时
sed -i '/ swap / s/^$.*$$/#\1/g' /etc/fstab #永久
## 重新命名主机，在所有主机上上添加如下命令，修改hosts文件

hostnamectl set-hostname master

   hostnamectl set-hostname node1

   hostnamectl set-hostname node2
## 修改主机名后使用su - root重新登陆

每台机器上的/etc/hosts文件都需要修改

su  - rootcat >> /etc/hosts << EOF 192.168.0.17 master192.168.0.89 node1192.168.0.11 node2192.168.0.19 node3EOF

# 安装kubeadm,kubelet和kubectl

kubeadm --》k8s的管理程序--》在master上运行的--》建立整个k8s集群，背后是执行了大量的脚本，帮助我们去启动k8s

kubelet --》在node节点上用来管理容器的--》管理docker，告诉docker程序去启动容器
master和node通信用的--》管理docker，告诉docker程序去启动容器
一个在集群中每个节点（node）上运行的代理。它保证容器（containers）都运行在 Pod 中。

kubectl --》在master上用来给node节点发号施令的程序，用来控制node节点的，告诉它们做什么事情的，是命令行操作的工具

集群里的每台服务器都需要安装

# Centos添加kubernetes YUM软件源

cat > /etc/yum.repos.d/kubernetes.repo << EOF
   [kubernetes]
   name=Kubernetes
   baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
   enabled=1
   gpgcheck=0
   repo_gpgcheck=0
   gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
   EOF

ubuntu修改源

#====
   ubuntu里修改源，使用阿里云的源，参考文档
   https://blog.csdn.net/wangyijieonline/article/details/105360138
   #===ubuntu系统里
   安装kubelet，kubeadm，kubectl
   添加apt key以及源（所有主机）

   #下载相关软件
   sudo apt update && sudo apt install -y apt-transport-https curl

   #下载apt-key.gpg
   curl -s https://mirrors.aliyun.com/kubernetes/apt/doc/apt-key.gpg | sudo apt-key add -

   #添加k8s的阿里云的源
   echo "deb https://mirrors.aliyun.com/kubernetes/apt/ kubernetes-xenial main" >>/etc/apt/sources.list.d/kubernetes.list

# ===ubuntu安装kubelet kubeadm kubectl
   sudo apt update
   apt install -y kubelet kubeadm kubectl
   systemctl enable --now kubelet

# ===centos里安装kubelet kubeadm kubectl
   #安装kubeadm,kubelet和kubectl
   yum install -y kubelet kubeadm kubectl
   #设置开机自启
   systemctl enable kubelet

# master主机执行

## 部署Kubernetes Master
   # 部署Kubernetes Master
   #提前准备coredns:1.8.4的镜像，后面需要使用,需要在每台机器上下载镜像
   [root@master ~]# docker pull coredns/coredns:1.8.4
   [root@master ~]# docker tag coredns/coredns:1.8.4 registry.aliyuncs.com/google_containers/coredns:v1.8.4

   #初始化操作在master服务器上执行
   [root@master ~]#kubeadm init \
   --apiserver-advertise-address=192.168.74.159 \
   --image-repository registry.aliyuncs.com/google_containers \
   --service-cidr=10.1.0.0/16 \
   --pod-network-cidr=10.244.0.0/16
   #192.168.0.17 是master的ip
   # --service-cidr string Use alternative range of IP address for service VIPs. (default "10.96.0.0/12")
   # --pod-network-cidr string Specify range of IP addresses for the pod network. If set, the control plane will automatically allocate CIDRs for every node.

输出结果

[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 192.168.0.17:6443 --token sxzm95.4blvhq1mnk3goyjo \
       --discovery-token-ca-cert-hash sha256:419d644656e24a113f94d7f8e01a820bb4030e3c0a19a32542bc27730103189a
   [root@master ~]#

按照提示操作

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

## node节点执行

建议：不要现在node节点上运行kubelet服务，不然会导致join失败，如果已经运行了，建议关闭，然后删除提示失败的文件和目录
   /etc/kubernetes/kubelet.conf
   /etc/kubernetes/pki/ca.crt
   rm -rf etc/kubernetes/{pki,kubelet.conf}
   ###########
   [root@node1 ~]# kubeadm join 192.168.0.17:6443 --token sxzm95.4blvhq1mnk3goyjo --discovery-token-ca-cert-hash sha256:419d644656e24a113f94d7f8e01a820bb4030e3c0a19a32542bc27730103189a

   注意：这里的执行的join是初始化master的时候输出结果里的kubeadm join

[root@node1 ~]#
第2台也加入集群
[root@node3 ~]# kubeadm join 192.168.0.17:6443 --token sxzm95.4blvhq1mnk3goyjo --discovery-token-ca-cert-hash sha256:419d644656e24a113f94d7f8e01a820bb4030e3c0a19a32542bc27730103189a

输出结果

[preflight] Running pre-flight checks
       [WARNING FileExisting-tc]: tc not found in system path
       [WARNING SystemVerification]: this Docker version is not on the list of validated versions: 20.10.5. Latest validated version: 19.03
   [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.

到这里则表示添加节点成功

## 安装网络插件(在master节点执行)

在家目录下vim一个kube-flannel.yml文件

在master服务器上执行
[root@master ~]# vim kube-flannel.yml

 ---apiVersion: policy/v1beta1kind: PodSecurityPolicymetadata:name: psp.flannel.unprivilegedannotations:seccomp.security.alpha.kubernetes.io/allowedProfileNames: docker/defaultseccomp.security.alpha.kubernetes.io/defaultProfileName: docker/defaultapparmor.security.beta.kubernetes.io/allowedProfileNames: runtime/defaultapparmor.security.beta.kubernetes.io/defaultProfileName: runtime/defaultspec:privileged: falsevolumes:- configMap- secret- emptyDir- hostPathallowedHostPaths:- pathPrefix: "/etc/cni/net.d"- pathPrefix: "/etc/kube-flannel"- pathPrefix: "/run/flannel"readOnlyRootFilesystem: false# Users and groupsrunAsUser:rule: RunAsAnysupplementalGroups:rule: RunAsAnyfsGroup:rule: RunAsAny# Privilege EscalationallowPrivilegeEscalation: falsedefaultAllowPrivilegeEscalation: false# CapabilitiesallowedCapabilities: ['NET_ADMIN', 'NET_RAW']defaultAddCapabilities: []requiredDropCapabilities: []# Host namespaceshostPID: falsehostIPC: falsehostNetwork: truehostPorts:- min: 0max: 65535# SELinuxseLinux:# SELinux is unused in CaaSPrule: 'RunAsAny'---kind: ClusterRoleapiVersion: rbac.authorization.k8s.io/v1metadata:name: flannelrules:- apiGroups: ['extensions']resources: ['podsecuritypolicies']verbs: ['use']resourceNames: ['psp.flannel.unprivileged']- apiGroups:- ""resources:- podsverbs:- get- apiGroups:- ""resources:- nodesverbs:- list- watch- apiGroups:- ""resources:- nodes/statusverbs:- patch---kind: ClusterRoleBindingapiVersion: rbac.authorization.k8s.io/v1metadata:name: flannelroleRef:apiGroup: rbac.authorization.k8s.iokind: ClusterRolename: flannelsubjects:- kind: ServiceAccountname: flannelnamespace: kube-system---apiVersion: v1kind: ServiceAccountmetadata:name: flannelnamespace: kube-system---kind: ConfigMapapiVersion: v1metadata:name: kube-flannel-cfgnamespace: kube-systemlabels:tier: nodeapp: flanneldata:cni-conf.json: |{"name": "cbr0","cniVersion": "0.3.1","plugins": [{"type": "flannel","delegate": {"hairpinMode": true,"isDefaultGateway": true}},{"type": "portmap","capabilities": {"portMappings": true}}]}net-conf.json: |{"Network": "10.244.0.0/16","Backend": {"Type": "vxlan"}}---apiVersion: apps/v1kind: DaemonSetmetadata:name: kube-flannel-dsnamespace: kube-systemlabels:tier: nodeapp: flannelspec:selector:matchLabels:app: flanneltemplate:metadata:labels:tier: nodeapp: flannelspec:affinity:nodeAffinity:requiredDuringSchedulingIgnoredDuringExecution:nodeSelectorTerms:- matchExpressions:- key: kubernetes.io/osoperator: Invalues:- linuxhostNetwork: truepriorityClassName: system-node-criticaltolerations:- operator: Existseffect: NoScheduleserviceAccountName: flannelinitContainers:- name: install-cniimage: quay.io/coreos/flannel:v0.13.1-rc2command:- cpargs:- -f- /etc/kube-flannel/cni-conf.json- /etc/cni/net.d/10-flannel.conflistvolumeMounts:- name: cnimountPath: /etc/cni/net.d- name: flannel-cfgmountPath: /etc/kube-flannel/containers:- name: kube-flannelimage: quay.io/coreos/flannel:v0.13.1-rc2command:- /opt/bin/flanneldargs:- --ip-masq- --kube-subnet-mgrresources:requests:cpu: "100m"memory: "50Mi"limits:cpu: "100m"memory: "50Mi"securityContext:privileged: falsecapabilities:add: ["NET_ADMIN", "NET_RAW"]env:- name: POD_NAMEvalueFrom:fieldRef:fieldPath: metadata.name- name: POD_NAMESPACEvalueFrom:fieldRef:fieldPath: metadata.namespacevolumeMounts:- name: runmountPath: /run/flannel- name: flannel-cfgmountPath: /etc/kube-flannel/volumes:- name: runhostPath:path: /run/flannel- name: cnihostPath:path: /etc/cni/net.d- name: flannel-cfgconfigMap:name: kube-flannel-cfg

部署flannel

[root@master ~]# kubectl apply -f kube-flannel.yml
   podsecuritypolicy.policy/psp.flannel.unprivileged created
   clusterrole.rbac.authorization.k8s.io/flannel created
   clusterrolebinding.rbac.authorization.k8s.io/flannel created
   serviceaccount/flannel created
   configmap/kube-flannel-cfg created
   daemonset.apps/kube-flannel-ds created
   [root@master ~]# ps aux|grep flannel
   root 320372 1.8 1.4 1265920 26824 ? Ssl 11:12 0:00 /opt/bin/flanneld --ip-masq --kube-subnet-mgr
   root 321071 0.0 0.0 12324 1088 pts/0 S+ 11:13 0:00 grep --color=auto flannel

查看集群状态

#等待节点准备完毕
   [root@master ~]# kubectl get nodes
   NAME STATUS ROLES AGE VERSION
   master Ready control-plane,master 161m v1.20.4
   node1 Ready <none> 135m v1.20.4
   node2 NotReady <none> 39s v1.20.4

   过一段时间，再次查看node节点会是ready状态，大概2-3分钟时间
   [root@master ~]# kubectl get nodes
   NAME STATUS ROLES AGE VERSION
   master Ready control-plane,master 163m v1.20.4
   node1 Ready <none> 136m v1.20.4
   node2 Ready <none> 2m5s v1.20.4

查看个个节点的详细信息
   [root@master ~]# kubectl get nodes -n kube-system -o wide
   NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
   master Ready control-plane,master 136m v1.22.1 192.168.0.17 <none> CentOS Linux 8 4.18.0-305.3.1.el8.x86_64 docker://20.10.8
   node1 Ready <none> 131m v1.22.1 192.168.0.89 <none> CentOS Linux 7 (Core) 3.10.0-1062.el7.x86_64 docker://20.10.8
   node2 Ready <none> 111s v1.22.1 192.168.0.11 <none> Ubuntu 20.04.3 LTS 5.4.0-80-generic docker://20.10.8
   node3 Ready <none> 130m v1.22.1 192.168.0.19 <none> CentOS Linux 8 4.18.0-305.3.1.el8.x86_64 docker://20.10.8
   [root@master ~]#

[root@master ~]# kubectl get pod -n kube-system
   NAME READY STATUS RESTARTS AGE
   coredns-7f89b7bc75-fjq7n 1/1 Running 0 48m
   coredns-7f89b7bc75-t5hnq 1/1 Running 0 48m
   etcd-master 1/1 Running 0 48m
   kube-apiserver-master 1/1 Running 0 48m
   kube-controller-manager-master 1/1 Running 0 48m
   kube-flannel-ds-kz8t9 1/1 Running 0 17m
   kube-flannel-ds-r2q5s 1/1 Running 0 17m
   kube-proxy-4jlr6 1/1 Running 0 48m
   kube-proxy-ppsr6 1/1 Running 0 22m
   kube-scheduler-master 1/1 Running 0 48m

#测试

创建nginx的pod

```
启动一个pod，背后是运行nginx镜像
[root@new-k8s-master ~]# kubectl run sc-nginx --image=nginx --port=8080
pod/sc-nginx created
[root@new-k8s-master ~]# kubectl get pod
NAME READY STATUS RESTARTS AGE
sc-nginx 0/1 ContainerCreating 0 5s
[root@new-k8s-master ~]#

等一下，会启动pod，因为需要去下载镜像文件
[root@new-k8s-master ~]# kubectl get pod
NAME READY STATUS RESTARTS AGE
sc-nginx 1/1 Running 0 64s
[root@new-k8s-master ~]#
[root@new-k8s-master ~]# kubectl get pod -o wide 显示详细的内容
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
sc-nginx 1/1 Running 0 97s 10.244.1.2 node1 <none> <none>
[root@new-k8s-master ~]#

```