通过kubeadm安装k8s集群
1、准备机器
- 开通三台机器，内网互通，配置公网ip。centos7.8/7.9，基础实验2c4g三台也可以
- 每台机器的hostname不要用localhost，可用k8s-master，k8s-node1，k8s-node2之类的【不包含下划线、小数点、大写字母】
2、安装钱置环境
2.1、基础环境
######################################################################### #关闭防火墙： 如果是云服务器，需要设置安全组策略放行端口 # https://kubernetes.io/zh/docs/setup/production-environment/tools/kubeadm/install-kubeadm/#check-required-ports systemctl stop firewalld systemctl disable firewalld # 修改 hostname hostnamectl set-hostname xxx # 查看修改结果 hostnamectl status # 设置 hostname 解析 echo "127.0.0.1 $(hostname)" >> /etc/hosts #关闭 selinux： sed -i 's/enforcing/disabled/' /etc/selinux/config setenforce 0 #关闭 swap： swapoff -a sed -ri 's/.*swap.*/#&/' /etc/fstab ## 修改配置 "##################配置路由转发################## \n" cat <<EOF | sudo tee /etc/modules-load.d/k8s.conf br_netfilter EOF echo 'net.ipv4.ip_forward = 1' >> /etc/sysctl.d/k8s.conf ## 必须 ipv6流量桥接 echo 'net.bridge.bridge-nf-call-ip6tables = 1' >> /etc/sysctl.d/k8s.conf ## 必须 ipv4流量桥接 echo 'net.bridge.bridge-nf-call-iptables = 1' >> /etc/sysctl.d/k8s.conf echo "net.ipv6.conf.all.disable_ipv6 = 1" >> /etc/sysctl.d/k8s.conf echo "net.ipv6.conf.default.disable_ipv6 = 1" >> /etc/sysctl.d/k8s.conf echo "net.ipv6.conf.lo.disable_ipv6 = 1" >> /etc/sysctl.d/k8s.conf echo "net.ipv6.conf.all.forwarding = 1" >> /etc/sysctl.d/k8s.conf sysctl -p modprobe br_netfilter sudo sysctl --system "##################安装ipvsadm相关软件################## \n" yum install -y ipset ipvsadm "##################配置ipvs################## \n" cat <<EOF | sudo tee /etc/sysconfig/modules/ipvs.modules #!/bin/bash modprobe -- ip_vs modprobe -- ip_vs_rr modprobe -- ip_vs_wrr modprobe -- ip_vs_sh modprobe -- nf_conntrack_ipv4 EOF chmod 755 /etc/sysconfig/modules/ipvs.modules sh /etc/sysconfig/modules/ipvs.modules ################################################################# reboot
2.2、docker环境
sudo yum remove docker* sudo yum install -y yum-utils #配置docker yum 源 sudo yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo #安装docker 19.03.9 yum install -y docker-ce-3:19.03.9-3.el7.x86_64 docker-ce-cli-3:19.03.9-3.el7.x86_64 containerd.io #启动服务 systemctl start docker systemctl enable docker #配置加速 sudo mkdir -p /etc/docker sudo tee /etc/docker/daemon.json <<-'EOF' { "registry-mirrors": ["https://82m9ar63.mirror.aliyuncs.com"] } EOF sudo systemctl daemon-reload sudo systemctl restart docker
2.3、安装k8s
# 配置K8S的yum源 cat <<EOF > /etc/yum.repos.d/kubernetes.repo [kubernetes] name=Kubernetes baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64 enabled=1 gpgcheck=0 repo_gpgcheck=0 gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg EOF # 卸载旧版本 yum remove -y kubelet kubeadm kubectl # 查看可以安装的版本 yum list kubelet --showduplicates | sort -r # 安装kubelet、kubeadm、kubectl 指定版本 yum install -y kubelet-1.21.0 kubeadm-1.21.0 kubectl-1.21.0 # 开机启动kubelet systemctl enable kubelet && systemctl start kubelet
2.4、初始化master节点
############下载核心镜像 kubeadm config images list：查看需要哪些镜像########### ####封装成images.sh文件 #!/bin/bash images=( kube-apiserver:v1.21.0 kube-proxy:v1.21.0 kube-controller-manager:v1.21.0 kube-scheduler:v1.21.0 coredns:v1.8.0 etcd:3.4.13-0 pause:3.4.1 ) for imageName in ${images[@]} ; do docker pull registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/$imageName done #####封装结束 chmod +x images.sh && ./images.sh # registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/coredns:v1.8.0 ##注意1.21.0版本的k8s coredns镜像比较特殊，结合阿里云需要特殊处理，重新打标签 docker tag registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/coredns:v1.8.0 registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/coredns/coredns:v1.8.0 ########kubeadm init 一个master######################## ########kubeadm join 其他worker######################## kubeadm init \ --apiserver-advertise-address=192.168.30.130 \ --image-repository registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images \ --kubernetes-version v1.21.0 \ --service-cidr=10.96.0.0/16 \ --pod-network-cidr=10.244.0.0/16 ## 注意：pod-cidr与service-cidr # cidr 无类别域间路由（Classless Inter-Domain Routing、CIDR） # 指定一个网络可达范围 pod的子网范围+service负载均衡网络的子网范围+本机ip的子网范围不能有重复域 ######按照提示继续###### ## init完成后第一步：复制相关文件夹 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 ## 导出环境变量 Alternatively, if you are the root user, you can run: export KUBECONFIG=/etc/kubernetes/admin.conf ### 部署一个pod网络 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/ ##############如下：安装calico##################### kubectl apply -f https://docs.projectcalico.org/manifests/calico.yaml ### 命令检查 kubectl get pod -A ##获取集群中所有部署好的应用Pod kubectl get nodes ##查看集群所有机器的状态 Then you can join any number of worker nodes by running the following on each as root: kubeadm join 192.168.30.130:6443 --token 0fhekd.7ehdbwmkzjoib5s7 \ --discovery-token-ca-cert-hash sha256:58ee5974b5a1f591c254351e750effa7cc28ca5391fa5b8bdf1f3a104222d3d9
2.5、初始化work节点
## 用master生成的命令即可 kubeadm join 172.24.80.222:6443 --token nz9azl.9bl27pyr4exy2wz4 \ --discovery-token-ca-cert-hash sha256:4bdc81a83b80f6bdd30bb56225f9013006a45ed423f131ac256ffe16bae73a20 ##过期怎么办 kubeadm token create --print-join-command kubeadm token create --ttl 0 --print-join-command kubeadm join --token y1eyw5.ylg568kvohfdsfco --discovery-token-ca-cert-hash sha256: 6c35e4f73f72afd89bf1c8c303ee55677d2cdb1342d67bb23c852aba2efc7c73
2.6、集群验证
#获取所有节点 kubectl get nodes #给节点打标签 ## k8s中万物皆对象。node:机器 Pod：应用容器 ###加标签 《h1》 kubectl label node k8s-02 node-role.kubernetes.io/worker='' ###去标签 kubectl label node k8s-02 node-role.kubernetes.io/worker- ## k8s集群，机器重启了会自动再加入集群，master重启了会自动再加入集群控制中心
2.7、设置ipvs模式
k8s整个集群为了访问通；默认是用iptables,性能下（kube-proxy在集群之间同步iptables的内容）
#1、查看默认kube-proxy 使用的模式 kubectl logs -n kube-system kube-proxy-28xv4 #2、需要修改 kube-proxy 的配置文件,修改mode 为ipvs。默认iptables，但是集群大了以后就很慢 kubectl edit cm kube-proxy -n kube-system 修改如下 ipvs: excludeCIDRs: null minSyncPeriod: 0s scheduler: "" strictARP: false syncPeriod: 30s kind: KubeProxyConfiguration metricsBindAddress: 127.0.0.1:10249 mode: "ipvs" ###修改了kube-proxy的配置，为了让重新生效，需要杀掉以前的Kube-proxy kubectl get pod -A|grep kube-proxy kubectl delete pod kube-proxy-pqgnt -n kube-system ### 修改完成后可以重启kube-proxy以生效
