随着容器项目的增多,项目的部署、环境区分、升级、回退、容灾等成为挑战,Google研发的k8s正能解决这一问题;本文高可用集群的网络拓扑结构为:两主两从,且Master节点处于内网中,而Node节点则是外网云服务器;由于节点不处于同一内网而导致搭建极其繁琐,故采取笔者认为最佳的解决方案——搭建VPN(使用Pritunl工具),统一虚拟子网(当然其他方法也有,但经过本人多次尝试VPN方案最为便捷);后文将着重讲解k8s的搭建步骤,分为具体步骤与脚本搭建(步骤若无特殊说明,则所有节点均需执行),以帮助大家避坑。
  
    
  
   服务器配置:
  
  
   8核16G(Master节点)
  
  
   2核4G(Node节点)
  
  
   软件环境:
  
  
   Ubuntu22.04版本
  
  
   Kubernetes1.23.6版本
  
  
   DockerCE20.10.21版本
  
  
   安装部署步骤
  
  
   关闭防火墙
  
  ufw disable
关闭swap分区
swapoff -a
sed -i 's#/swap.img##/swap.img#g' /etc/fstab
允许iptables&&ipvs
cat <<EOF | sudo tee /etc/modules-load.d/k8s.conf
overlay
br_netfilter
modprobe overlay
modprobe br_netfilter
cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
sudo sysctl --system
sudo sysctl -w net.ipv4.ip_forward=1
sudo apt-get install ipset ipvsadm
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack 
修改docker的cgroup
# 完全替换daemon.json
# 若不想使用这套配置,可自行添加"exec-opts": ["native.cgroupdriver=systemd"]即可
cat <<EOF | sudo tee /etc/docker/daemon.json
  "exec-opts": ["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "10m"
  "storage-driver": "overlay2"
# 重启docker
sudo systemctl enable docker
sudo systemctl daemon-reload
sudo systemctl restart docker
修改journald日志设置
此处为防止服务器日志文件过大而作设置
cat <<EOF | sudo tee /etc/systemd/journald.conf
[Journal]
Storage=persistent
Compress=yes
SysnIntervalSec=5m
RateLimitInterval=30s
RateLimitBurst=1000
SystemMaxUse=10G
SystemMaxFileSize=200M
MaxRetentionSec=2week
ForwardToSyslog=no
systemctl restart systemd-journald
加载k8s资源列表
curl https://mirrors.aliyun.com/kubernetes/apt/doc/apt-key.gpg | sudo apt-key add
echo "deb https://mirrors.aliyun.com/kubernetes/apt kubernetes-xenial main" >>  /etc/apt/sources.list
安装k8s包
#参考kubadm官网:https:
sudo apt-get update
sudo apt-get upgrade -y
sudo apt-get install -y apt-transport-https ca-certificates curl
安装kubelet、kubeadm、kubectl
sudo apt install kubeadm=1.23.6-00
sudo apt install kubectl=1.23.6-00
sudo apt install kubelet=1.23.6-00
sudo apt-mark hold kubelet kubeadm kubectl
systemctl enable kubelet 
修改k8s为ipvs模式
cat <<EOF | sudo tee /etc/default/kubelet
KUBE_PROXY_MODE="ipvs"
下载k8s相关镜像
images=(
    kube-apiserver:v1.23.6
    kube-controller-manager:v1.23.6
    kube-scheduler:v1.23.6
    kube-proxy:v1.23.6
    pause:3.6
    etcd:3.5.1-0
    coredns:v1.8.6
for imageName in ${images[@]} ; do
        docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/${imageName}
        if [ $(echo $imageName | awk -F [":"] '{print $1}') != "coredns" ]
          
          docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/${imageName} k8s.gcr.io/${imageName}
          
          docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/${imageName} k8s.gcr.io/coredns/${imageName}
        docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/${imageName}
下载网络组件镜像镜像
docker pull quay.io/coreos/flannel:v0.13.1-rc1
配置Host
在所有节点上均需配置好host
vim /etc/hosts
192.168.239.4 k8s-master01
192.168.239.5 k8s-master02
192.168.239.3 k8s-node-01
192.168.239.2 k8s-node-02
kubectl配置IP
如果采用搭建VPN虚拟子网或者想要指定不同网卡的ip则要执行这一步骤
systemctl status kubelet
打开红框所示文件
ExecStart=/usr/bin/kubelet $KUBELET_KUBECONFIG_ARGS $KUBELET_CONFIG_ARGS $KUBELET_KUBEADM_ARGS $KUBELET_EXTRA_ARGS --node-ip=192.168.239.4
reboot
高可用组件安装
仅在两个Master节点执行
Nginx负载均衡
apt install nginx -y
cd /etc/nginx
vim nginx.conf
log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';                     
stream {
    log_format  main  '$remote_addr $upstream_addr - [$time_local] $status $upstream_bytes_sent';
    access_log  /var/log/nginx/k8s-access.log  main;
    upstream k8s-apiserver {
       server 192.168.239.4:6443;   
       server 192.168.239.5:6443;   
    server {
       listen 16443;  
       proxy_pass k8s-apiserver;
nginx -t
systemctl restart nginx
cd sites-enabled
rm -rf default
systemctl restart nginx
ps -ef | grep nginx 
Keepalived(状态检测和故障隔离)
apt install -y keepalived 
vim /etc/keepalived/keepalived.conf
需要注意修改的是:
state:主节点为 MASTER,对应的备份节点为 BACKUP
interface:修改为你当前使用的网卡,ifconfig查看
mcast_src_ip:当前主机的内网IP
virtual_ipaddress:虚拟IP,主节点和备份节点的需一致
! Configuration File for keepalived
global_defs {
    
    router_id k8s-master01
    script_user root
    enable_script_security    
vrrp_script chk_apiserver {
    script "/etc/keepalived/check_apiserver.sh"
    
    interval 2
    
    weight -5
    fall 3  
    rise 2
vrrp_instance VI_1 {
    
    state MASTER
    
    interface ens33
    
    mcast_src_ip 192.168.239.4 
    
    virtual_router_id 100
    
    priority 100
     
    nopreempt 
    
    advert_int 2
    
    authentication {
        auth_type PASS
        auth_pass K8SHA_KA_AUTH
    
    virtual_ipaddress {
            
        192.168.100.190
    track_script {
       chk_apiserver
编写监控脚本
vim /etc/keepalived/check_apiserver.sh
err=0
for k in $(seq 1 5)
    check_code=$(pgrep kube-apiserver)
    if [[ $check_code == "" ]]; then
        err=$(expr $err + 1)
        sleep 5
        continue
        err=0
        break
if [[ $err != "0" ]]; then
    echo "systemctl stop keepalived"
    /usr/bin/systemctl stop keepalived
    exit 1
    exit 0
设置开机自启动
systemctl daemon-reload
systemctl start nginx
systemctl start keepalived
systemctl enable nginx
systemctl enable keepalived
集群初始化
仅在两个Master节点执行
kubeadm init \
  --apiserver-advertise-address=192.168.239.4 \
  --image-repository registry.aliyuncs.com/google_containers \
  --control-plane-endpoint=192.168.100.190:16443 \
  --kubernetes-version v1.23.6 \
  --service-cidr=10.96.0.0/12 \
  --pod-network-cidr=10.244.0.0/16 \
  --upload-certs
systemctl daemon-reload
systemctl restart kubelet
systemctl status kubelet
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
此时k8s搭建已接近尾声,但还缺少CNI网络组件
部署CNI网络插件
这里选用flannel作CNI网络插件,请确保各节点都存在【安装部署】中的flannel镜像再部署,否则节点容易NotReady
准备官方kube-flannel.yaml文件
apiVersion: policy/v1beta1
kind: PodSecurityPolicy
metadata:
  name: psp.flannel.unprivileged
  annotations:
    seccomp.security.alpha.kubernetes.io/allowedProfileNames: docker/default
    seccomp.security.alpha.kubernetes.io/defaultProfileName: docker/default
    apparmor.security.beta.kubernetes.io/allowedProfileNames: runtime/default
    apparmor.security.beta.kubernetes.io/defaultProfileName: runtime/default
spec:
  privileged: false
  volumes:
  - configMap
  - secret
  - emptyDir
  - hostPath
  allowedHostPaths:
  - pathPrefix: "/etc/cni/net.d"
  - pathPrefix: "/etc/kube-flannel"
  - pathPrefix: "/run/flannel"
  readOnlyRootFilesystem: false
  
  runAsUser:
    rule: RunAsAny
  supplementalGroups:
    rule: RunAsAny
  fsGroup:
    rule: RunAsAny
  
  allowPrivilegeEscalation: false
  defaultAllowPrivilegeEscalation:
    
 false
  
  allowedCapabilities: ['NET_ADMIN', 'NET_RAW']
  defaultAddCapabilities: []
  requiredDropCapabilities: []
  
  hostPID: false
  hostIPC: false
  hostNetwork: true
  hostPorts:
  - min: 0
    max: 65535
  
  seLinux:
    
    rule: 'RunAsAny'
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: flannel
rules:
- apiGroups: ['extensions']
  resources: ['podsecuritypolicies']
  verbs: ['use']
  resourceNames: ['psp.flannel.unprivileged']
- apiGroups:
  - ""
  resources:
  - pods
  verbs:
  - get
- apiGroups:
  - ""
  resources:
  - nodes
  verbs:
  - list
  - watch
- apiGroups:
  - ""
  resources:
  - nodes/status
  verbs:
  - patch
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: flannel
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: flannel
subjects:
- kind: ServiceAccount
  name: flannel
  namespace: kube-system
apiVersion: v1
kind: ServiceAccount
metadata:
  name: flannel
  namespace: kube-system
kind: ConfigMap
apiVersion: v1
metadata:
  name: kube-flannel-cfg
  namespace: kube-system
  labels:
    tier: node
    app: flannel
data:
  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/v1
kind: DaemonSet
metadata:
  name: kube-flannel-ds
  namespace: kube-system
  labels:
    tier: node
    app: flannel
spec:
  selector:
    matchLabels:
      app: flannel
  template:
    metadata:
      labels:
        tier: node
        app: flannel
    spec:
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
            - matchExpressions:
              - key: kubernetes.io/os
                operator: In
                values:
                - linux
      hostNetwork: true
      priorityClassName: system-node-critical
      tolerations:
      - operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni
        image: quay.io/coreos/flannel:v0.13.1-rc1
        command:
        - cp
        args:
        - -f
        - /etc/kube-flannel/cni-conf.json
        - /etc/cni/net.d/10-flannel.conflist
        volumeMounts:
        - name: cni
          mountPath: /etc/cni/net.d
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      containers:
      - name: kube-flannel
        image: quay.io/coreos/flannel:v0.13.1-rc1
        command:
        - /opt/bin/flanneld
        args:
        - --public-ip=$(PUBLIC_IP)
        - --iface=tun0
        - --ip-masq
        - --kube-subnet-mgr
        resources:
          requests:
            cpu: "100m"
            memory: "50Mi"
          limits:
            cpu: "100m"
            memory: "50Mi"
        securityContext:
          privileged: false
          capabilities:
            add: ["NET_ADMIN", "NET_RAW"]
        - name: PUBLIC_IP
          valueFrom:
            fieldRef:
              fieldPath: status.podIP
        - name: POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.name
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        volumeMounts:
        - name: run
          mountPath: /run/flannel
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      volumes:
      - name: run
        hostPath:
          path: /run/flannel
      - name: cni
        hostPath:
          path: /etc/cni/net.d
      - name: flannel-cfg
        configMap:
          name: kube-flannel-cfg
修改yaml文件配置
使用vpn方式时,需修改下方配置,指定虚拟网卡
containers:
      - name: kube-flannel
        image: rancher/mirrored-flannelcni-flannel:v0.16.1
        command:
        - /opt/bin/flanneld
        args:
        - --public-ip=$(PUBLIC_IP)   
        - --iface=eth0               
        - --ip-masq
        - --kube-subnet-mgr
        - name: PUBLIC_IP
          valueFrom:
            fieldRef:
              fieldPath: status.podIP
启动flannel网络插件
kubectl apply -f kube-flannel,yml
开启ipvs模式
lsmod|grep ip_vs
kubectl edit cm kube-proxy -n kube-system
kubectl delete pod -l k8s-app=kube-proxy -n kube-system
ipvsadm -Ln
重置k8s环境
该步骤适用于重置k8s,但不会卸载k8s环境(脚本方式)
#!/bin/bash
kubeadm reset
iptables -F && iptables -t nat -F && iptables -t mangle -F && iptables -X
systemctl stop kubelet
systemctl stop docker
rm -rf /var/lib/cni/*
rm -rf /var/lib/kubelet/*
rm -rf /etc/cni/*
ifconfig cni0 down
ifconfig flannel.1 down
ifconfig docker0 down
ip link delete cni0
ip link delete flannel.1
systemctl start docker
rm -rf $HOME/.kube
彻底卸载k8s环境
谨慎执行,该步骤适用于k8s环境装坏了,彻底重头再来(脚本方式)
#!/bin/bash
echo "-----------------------------------重置kubeadm-----------------------------------"
kubeadm reset -f
echo "-----------------------------------开始卸载-----------------------------------"
sudo apt-get purge -y --auto-remove kubernetes-cni
sudo apt-get purge -y --auto-remove kubeadm
sudo apt-get purge -y --auto-remove kubectl
sudo apt-get purge -y --auto-remove kubelet
echo "-----------------------------------删除遗留文件-----------------------------------"
modprobe -r ipip
rm -rf ~/.kube/
rm -rf /etc/kubernetes/
rm -rf /etc/systemd/system/kubelet.service.d
rm -rf /etc/systemd/system/kubelet.service
rm -rf /usr/bin/kube*
rm -rf /etc/cni
rm -rf /opt/cni
rm -rf /var/lib/etcd
rm -rf /var/etcd
apt clean all
apt remove -f kube*
echo "-----------------------------------查看是否残留文件-----------------------------------"
dpkg -l | grep kube
echo "-----------------------------------若有残留文件,使用sudo apt-get purge   --auto-remove -----------------------------------"
复制代码