主機名 | Centos版本 | ip | docker version | flannel version | Keepalived version | 主機配置 | 備註 |
---|---|---|---|---|---|---|---|
lvs-keepalived01 | 7.6.1810 | 172.27.34.28 | / | / | v1.3.5 | 4C4G | lvs-keepalived |
lvs-keepalived01 | 7.6.1810 | 172.27.34.29 | / | / | v1.3.5 | 4C4G | lvs-keepalived |
master01 | 7.6.1810 | 172.27.34.35 | 18.09.9 | v0.11.0 | / | 4C4G | control plane |
master02 | 7.6.1810 | 172.27.34.36 | 18.09.9 | v0.11.0 | / | 4C4G | control plane |
master03 | 7.6.1810 | 172.27.34.37 | 18.09.9 | v0.11.0 | / | 4C4G | control plane |
work01 | 7.6.1810 | 172.27.34.161 | 18.09.9 | / | / | 4C4G | worker nodes |
work02 | 7.6.1810 | 172.27.34.162 | 18.09.9 | / | / | 4C4G | worker nodes |
work03 | 7.6.1810 | 172.27.34.163 | 18.09.9 | / | / | 4C4G | worker nodes |
VIP | 7.6.1810 | 172.27.34.222 | / | / | v1.3.5 | 4C4G | 在lvs-keepalived兩臺主機上浮動 |
client | 7.6.1810 | 172.27.34.85 | / | / | / | 4C4G | client |
共有9臺服務器,2臺爲lvs-keepalived集羣,3臺control plane集羣,3臺work集羣,1臺client。node
主機名 | kubelet version | kubeadm version | kubectl version | 備註 |
---|---|---|---|---|
master01 | v1.16.4 | v1.16.4 | v1.16.4 | kubectl選裝 |
master02 | v1.16.4 | v1.16.4 | v1.16.4 | kubectl選裝 |
master03 | v1.16.4 | v1.16.4 | v1.16.4 | kubectl選裝 |
work01 | v1.16.4 | v1.16.4 | v1.16.4 | kubectl選裝 |
work02 | v1.16.4 | v1.16.4 | v1.16.4 | kubectl選裝 |
work03 | v1.16.4 | v1.16.4 | v1.16.4 | kubectl選裝 |
client | / | / | v1.16.4 | client |
本文采用kubeadm方式搭建高可用k8s集羣,k8s集羣的高可用實際是k8s各核心組件的高可用,這裏使用集羣模式(針對apiserver來說),架構以下:linux
核心組件 | 高可用模式 | 高可用實現方式 |
---|---|---|
apiserver | 集羣 | lvs+keepalived |
controller-manager | 主備 | leader election |
scheduler | 主備 | leader election |
etcd | 集羣 | kubeadm |
- apiserver 經過lvs-keepalived實現高可用,vip將請求分發至各個control plane節點的apiserver組件;
- controller-manager k8s內部經過選舉方式產生領導者(由--leader-elect 選型控制,默認爲true),同一時刻集羣內只有一個controller-manager組件運行;
- scheduler k8s內部經過選舉方式產生領導者(由--leader-elect 選型控制,默認爲true),同一時刻集羣內只有一個scheduler組件運行;
- etcd 經過運行kubeadm方式自動建立集羣來實現高可用,部署的節點數爲奇數,3節點方式最多容忍一臺機器宕機。
本文全部的服務器都爲Centos7.6,Centos7.6安裝詳見:Centos7.6操做系統安裝及優化全紀錄 nginx
安裝Centos時已經禁用了防火牆和selinux並設置了阿里源。git
control plane和work節點都執行本部分操做,以master01爲例記錄搭建過程。github
[root@centos7 ~]# hostnamectl set-hostname master01 [root@centos7 ~]# more /etc/hostname master01
退出從新登錄便可顯示新設置的主機名master01,各服務器修改成對應的主機名。算法
[root@master01 ~]# cat >> /etc/hosts << EOF 172.27.34.35 master01 172.27.34.36 master02 172.27.34.37 master03 172.27.34.161 work01 172.27.34.162 work02 172.27.34.163 work03 EOF
[root@master01 ~]# cat /sys/class/net/ens160/address [root@master01 ~]# cat /sys/class/dmi/id/product_uuid
保證各節點mac和uuid惟一docker
[root@master01 ~]# swapoff -a
若須要重啓後也生效,在禁用swap後還需修改配置文件/etc/fstab,註釋swapjson
[root@master01 ~]# sed -i.bak '/swap/s/^/#/' /etc/fstab
本文的k8s網絡使用flannel,該網絡須要設置內核參數bridge-nf-call-iptables=1,修改這個參數須要系統有br_netfilter模塊。centos
查看br_netfilter模塊:api
[root@master01 ~]# lsmod |grep br_netfilter
若是系統沒有br_netfilter模塊則執行下面的新增命令,若有則忽略。
臨時新增br_netfilter模塊:
[root@master01 ~]# modprobe br_netfilter
該方式重啓後會失效
永久新增br_netfilter模塊:
[root@master01 ~]# cat > /etc/rc.sysinit << EOF #!/bin/bash for file in /etc/sysconfig/modules/*.modules ; do [ -x $file ] && $file done EOF [root@master01 ~]# cat > /etc/sysconfig/modules/br_netfilter.modules << EOF modprobe br_netfilter EOF [root@master01 ~]# chmod 755 /etc/sysconfig/modules/br_netfilter.modules
[root@master01 ~]# sysctl net.bridge.bridge-nf-call-iptables=1 net.bridge.bridge-nf-call-iptables = 1 [root@master01 ~]# sysctl net.bridge.bridge-nf-call-ip6tables=1 net.bridge.bridge-nf-call-ip6tables = 1
[root@master01 ~]# cat <<EOF > /etc/sysctl.d/k8s.conf net.bridge.bridge-nf-call-ip6tables = 1 net.bridge.bridge-nf-call-iptables = 1 EOF [root@master01 ~]# sysctl -p /etc/sysctl.d/k8s.conf net.bridge.bridge-nf-call-ip6tables = 1 net.bridge.bridge-nf-call-iptables = 1
[root@master01 ~]# 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=1 repo_gpgcheck=1 gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg EOF
- [] 中括號中的是repository id,惟一,用來標識不一樣倉庫
- name 倉庫名稱,自定義
- baseurl 倉庫地址
- enable 是否啓用該倉庫,默認爲1表示啓用
- gpgcheck 是否驗證從該倉庫得到程序包的合法性,1爲驗證
- repo_gpgcheck 是否驗證元數據的合法性 元數據就是程序包列表,1爲驗證
- gpgkey=URL 數字簽名的公鑰文件所在位置,若是gpgcheck值爲1,此處就須要指定gpgkey文件的位置,若是gpgcheck值爲0就不須要此項了
[root@master01 ~]# yum clean all [root@master01 ~]# yum -y makecache
配置master01到master0二、master03免密登陸,本步驟只在master01上執行。
[root@master01 ~]# ssh-keygen -t rsa
[root@master01 ~]# ssh-copy-id -i /root/.ssh/id_rsa.pub root@172.27.34.35 [root@master01 ~]# ssh-copy-id -i /root/.ssh/id_rsa.pub root@172.27.34.36
[root@master01 ~]# ssh 172.27.34.36 [root@master01 ~]# ssh master03
master01能夠直接登陸master02和master03,不須要輸入密碼。
重啓各control plane和work節點。
control plane和work節點都執行本部分操做。
[root@master01 ~]# yum install -y yum-utils device-mapper-persistent-data lvm2
[root@master01 ~]# yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
[root@master01 ~]# yum list docker-ce --showduplicates | sort -r
[root@master01 ~]# yum install docker-ce-18.09.9 docker-ce-cli-18.09.9 containerd.io -y
指定安裝的docker版本爲18.09.9
[root@master01 ~]# systemctl start docker [root@master01 ~]# systemctl enable docker
[root@master01 ~]# yum -y install bash-completion
[root@master01 ~]# source /etc/profile.d/bash_completion.sh
因爲Docker Hub的服務器在國外,下載鏡像會比較慢,能夠配置鏡像加速器。主要的加速器有:Docker官方提供的中國registry mirror、阿里雲加速器、DaoCloud 加速器,本文以阿里加速器配置爲例。
登錄地址爲:https://cr.console.aliyun.com ,未註冊的能夠先註冊阿里雲帳戶
配置daemon.json文件
[root@master01 ~]# mkdir -p /etc/docker [root@master01 ~]# tee /etc/docker/daemon.json <<-'EOF' { "registry-mirrors": ["https://v16stybc.mirror.aliyuncs.com"] } EOF
重啓服務
[root@master01 ~]# systemctl daemon-reload [root@master01 ~]# systemctl restart docker
加速器配置完成
[root@master01 ~]# docker --version [root@master01 ~]# docker run hello-world
經過查詢docker版本和運行容器hello-world來驗證docker是否安裝成功。
修改daemon.json,新增‘"exec-opts": ["native.cgroupdriver=systemd"’
[root@master01 ~]# more /etc/docker/daemon.json { "registry-mirrors": ["https://v16stybc.mirror.aliyuncs.com"], "exec-opts": ["native.cgroupdriver=systemd"] }
[root@master01 ~]# systemctl daemon-reload [root@master01 ~]# systemctl restart docker
修改cgroupdriver是爲了消除告警: [WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/
control plane和work節點都執行本部分操做。
[root@master01 ~]# yum list kubelet --showduplicates | sort -r
本文安裝的kubelet版本是1.16.4,該版本支持的docker版本爲1.13.1, 17.03, 17.06, 17.09, 18.06, 18.09。
[root@master01 ~]# yum install -y kubelet-1.16.4 kubeadm-1.16.4 kubectl-1.16.4
- kubelet 運行在集羣全部節點上,用於啓動Pod和容器等對象的工具
- kubeadm 用於初始化集羣,啓動集羣的命令工具
- kubectl 用於和集羣通訊的命令行,經過kubectl能夠部署和管理應用,查看各類資源,建立、刪除和更新各類組件
啓動kubelet並設置開機啓動
[root@master01 ~]# systemctl enable kubelet && systemctl start kubelet
[root@master01 ~]# echo "source <(kubectl completion bash)" >> ~/.bash_profile [root@master01 ~]# source .bash_profile
Kubernetes幾乎全部的安裝組件和Docker鏡像都放在goolge本身的網站上,直接訪問可能會有網絡問題,這裏的解決辦法是從阿里雲鏡像倉庫下載鏡像,拉取到本地之後改回默認的鏡像tag。本文經過運行image.sh腳本方式拉取鏡像。
[root@master01 ~]# more image.sh #!/bin/bash url=registry.cn-hangzhou.aliyuncs.com/loong576 version=v1.16.4 images=(`kubeadm config images list --kubernetes-version=$version|awk -F '/' '{print $2}'`) for imagename in ${images[@]} ; do docker pull $url/$imagename docker tag $url/$imagename k8s.gcr.io/$imagename docker rmi -f $url/$imagename done
url爲阿里雲鏡像倉庫地址,version爲安裝的kubernetes版本。
運行腳本image.sh,下載指定版本的鏡像
[root@master01 ~]# ./image.sh [root@master01 ~]# docker images
master01節點執行本部分操做。
[root@master01 ~]# more kubeadm-config.yaml apiVersion: kubeadm.k8s.io/v1beta2 kind: ClusterConfiguration kubernetesVersion: v1.16.4 apiServer: certSANs: #填寫全部kube-apiserver節點的hostname、IP、VIP - master01 - master02 - master03 - work01 - work02 - work03 - 172.27.34.35 - 172.27.34.36 - 172.27.34.37 - 172.27.34.161 - 172.27.34.162 - 172.27.34.163 - 172.27.34.222 controlPlaneEndpoint: "172.27.34.222:6443" networking: podSubnet: "10.244.0.0/16"
kubeadm.conf爲初始化的配置文件
在master01上起虛ip:172.27.34.222
[root@master01 ~]# ifconfig ens160:2 172.27.34.222 netmask 255.255.255.0 up
起虛ip目的是爲了執行master01的初始化,待初始化完成後去掉該虛ip
[root@master01 ~]# kubeadm init --config=kubeadm-config.yaml
記錄kubeadm join的輸出,後面須要這個命令將work節點和其餘control plane節點加入集羣中。
You can now join any number of control-plane nodes by copying certificate authorities and service account keys on each node and then running the following as root: kubeadm join 172.27.34.222:6443 --token lw90fv.j1lease5jhzj9ih2 \ --discovery-token-ca-cert-hash sha256:79575e7a39eac086e121364f79e58a33f9c9de2a4e9162ad81d0abd1958b24f4 \ --control-plane Then you can join any number of worker nodes by running the following on each as root: kubeadm join 172.27.34.222:6443 --token lw90fv.j1lease5jhzj9ih2 \ --discovery-token-ca-cert-hash sha256:79575e7a39eac086e121364f79e58a33f9c9de2a4e9162ad81d0abd1958b24f4
初始化失敗:
若是初始化失敗,可執行kubeadm reset後從新初始化
[root@master01 ~]# kubeadm reset [root@master01 ~]# rm -rf $HOME/.kube/config
[root@master01 ~]# echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> ~/.bash_profile [root@master01 ~]# source .bash_profile
本文全部操做都在root用戶下執行,若爲非root用戶,則執行以下操做:
mkdir -p $HOME/.kube cp -i /etc/kubernetes/admin.conf $HOME/.kube/config chown $(id -u):$(id -g) $HOME/.kube/config
在master01上新建flannel網絡
[root@master01 ~]# kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/2140ac876ef134e0ed5af15c65e414cf26827915/Documentation/kube-flannel.yml
因爲網絡緣由,可能會安裝失敗,能夠在文末直接下載kube-flannel.yml文件,而後再執行apply
在master01上運行腳本cert-main-master.sh,將證書分發至master02和master03
[root@master01 ~]# ll|grep cert-main-master.sh -rwxr--r-- 1 root root 638 1月 16 10:25 cert-main-master.sh [root@master01 ~]# more cert-main-master.sh USER=root # customizable CONTROL_PLANE_IPS="172.27.34.36 172.27.34.37" for host in ${CONTROL_PLANE_IPS}; do scp /etc/kubernetes/pki/ca.crt "${USER}"@$host: scp /etc/kubernetes/pki/ca.key "${USER}"@$host: scp /etc/kubernetes/pki/sa.key "${USER}"@$host: scp /etc/kubernetes/pki/sa.pub "${USER}"@$host: scp /etc/kubernetes/pki/front-proxy-ca.crt "${USER}"@$host: scp /etc/kubernetes/pki/front-proxy-ca.key "${USER}"@$host: scp /etc/kubernetes/pki/etcd/ca.crt "${USER}"@$host:etcd-ca.crt # Quote this line if you are using external etcd scp /etc/kubernetes/pki/etcd/ca.key "${USER}"@$host:etcd-ca.key done
在master02上運行腳本cert-other-master.sh,將證書移至指定目錄
[root@master02 ~]# more cert-other-master.sh USER=root # customizable mkdir -p /etc/kubernetes/pki/etcd mv /${USER}/ca.crt /etc/kubernetes/pki/ mv /${USER}/ca.key /etc/kubernetes/pki/ mv /${USER}/sa.pub /etc/kubernetes/pki/ mv /${USER}/sa.key /etc/kubernetes/pki/ mv /${USER}/front-proxy-ca.crt /etc/kubernetes/pki/ mv /${USER}/front-proxy-ca.key /etc/kubernetes/pki/ mv /${USER}/etcd-ca.crt /etc/kubernetes/pki/etcd/ca.crt # Quote this line if you are using external etcd mv /${USER}/etcd-ca.key /etc/kubernetes/pki/etcd/ca.key [root@master02 ~]# ./cert-other-master.sh
在master03上也運行腳本cert-other-master.sh
[root@master03 ~]# pwd /root [root@master03 ~]# ll|grep cert-other-master.sh -rwxr--r-- 1 root root 484 1月 16 10:30 cert-other-master.sh [root@master03 ~]# ./cert-other-master.sh
[root@master03 ~]# kubeadm join 172.27.34.222:6443 --token lw90fv.j1lease5jhzj9ih2 --discovery-token-ca-cert-hash sha256:79575e7a39eac086e121364f79e58a33f9c9de2a4e9162ad81d0abd1958b24f4 --control-plane
運行初始化master生成的control plane節點加入集羣的命令
[root@master03 ~]# kubeadm join 172.27.34.222:6443 --token 0p7rzn.fdanprq4y8na36jh --discovery-token-ca-cert-hash sha256:fc7a828208d554329645044633159e9dc46b0597daf66769988fee8f3fc0636b --control-plane
master02和master03加載環境變量
[root@master02 ~]# scp master01:/etc/kubernetes/admin.conf /etc/kubernetes/ [root@master02 ~]# echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> ~/.bash_profile [root@master02 ~]# source .bash_profile [root@master03 ~]# scp master01:/etc/kubernetes/admin.conf /etc/kubernetes/ [root@master03 ~]# echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> ~/.bash_profile [root@master03 ~]# source .bash_profile
該步操做是爲了在master02和master03上也能執行kubectl命令。
[root@master01 ~]# kubectl get nodes [root@master01 ~]# kubectl get po -o wide -n kube-system
發現master01和master03下載flannel異常,分別在master01和master03上手動下載該鏡像後正常。
[root@master01 ~]# docker pull registry.cn-hangzhou.aliyuncs.com/loong576/flannel:v0.11.0-amd64 [root@master03 ~]# docker pull registry.cn-hangzhou.aliyuncs.com/loong576/flannel:v0.11.0-amd64
[root@work01 ~]# kubeadm join 172.27.34.222:6443 --token lw90fv.j1lease5jhzj9ih2 --discovery-token-ca-cert-hash sha256:79575e7a39eac086e121364f79e58a33f9c9de2a4e9162ad81d0abd1958b24f4
運行初始化master生成的work節點加入集羣的命令
[root@work02 ~]# kubeadm join 172.27.34.222:6443 --token lw90fv.j1lease5jhzj9ih2 --discovery-token-ca-cert-hash sha256:79575e7a39eac086e121364f79e58a33f9c9de2a4e9162ad81d0abd1958b24f4
[root@work03 ~]# kubeadm join 172.27.34.222:6443 --token lw90fv.j1lease5jhzj9ih2 --discovery-token-ca-cert-hash sha256:79575e7a39eac086e121364f79e58a33f9c9de2a4e9162ad81d0abd1958b24f4
[root@master01 ~]# kubectl get nodes [root@master01 ~]# kubectl get po -o wide -n kube-system
lvs-keepalived01和lvs-keepalived02都執行本操做。
LVS無需安裝,安裝的是管理工具,第一種叫ipvsadm,第二種叫keepalive。ipvsadm是經過命令行管理,而keepalive讀取配置文件管理。
[root@lvs-keepalived01 ~]# yum -y install ipvsadm
把ipvsadm模塊加載進系統
[root@lvs-keepalived01 ~]# ipvsadm IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn [root@lvs-keepalived01 ~]# lsmod | grep ip_vs ip_vs 145497 0 nf_conntrack 133095 1 ip_vs libcrc32c 12644 3 xfs,ip_vs,nf_conntrack
lvs相關實踐詳見:LVS+Keepalived+Nginx負載均衡搭建測試
lvs-keepalived01和lvs-keepalived02都執行本操做。
[root@lvs-keepalived01 ~]# yum -y install keepalived
lvs-keepalived01配置以下:
[root@lvs-keepalived01 ~]# more /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { router_id lvs-keepalived01 #router_id 機器標識,一般爲hostname,但不必定非得是hostname。故障發生時,郵件通知會用到。 } vrrp_instance VI_1 { #vrrp實例定義部分 state MASTER #設置lvs的狀態,MASTER和BACKUP兩種,必須大寫 interface ens160 #設置對外服務的接口 virtual_router_id 100 #設置虛擬路由標示,這個標示是一個數字,同一個vrrp實例使用惟一標示 priority 100 #定義優先級,數字越大優先級越高,在一個vrrp——instance下,master的優先級必須大於backup advert_int 1 #設定master與backup負載均衡器之間同步檢查的時間間隔,單位是秒 authentication { #設置驗證類型和密碼 auth_type PASS #主要有PASS和AH兩種 auth_pass 1111 #驗證密碼,同一個vrrp_instance下MASTER和BACKUP密碼必須相同 } virtual_ipaddress { #設置虛擬ip地址,能夠設置多個,每行一個 172.27.34.222 } } virtual_server 172.27.34.222 6443 { #設置虛擬服務器,須要指定虛擬ip和服務端口 delay_loop 6 #健康檢查時間間隔 lb_algo wrr #負載均衡調度算法 lb_kind DR #負載均衡轉發規則 #persistence_timeout 50 #設置會話保持時間,對動態網頁很是有用 protocol TCP #指定轉發協議類型,有TCP和UDP兩種 real_server 172.27.34.35 6443 { #配置服務器節點1,須要指定real server的真實IP地址和端口 weight 10 #設置權重,數字越大權重越高 TCP_CHECK { #realserver的狀態監測設置部分單位秒 connect_timeout 10 #鏈接超時爲10秒 retry 3 #重連次數 delay_before_retry 3 #重試間隔 connect_port 6443 #鏈接端口爲6443,要和上面的保持一致 } } real_server 172.27.34.36 6443 { #配置服務器節點1,須要指定real server的真實IP地址和端口 weight 10 #設置權重,數字越大權重越高 TCP_CHECK { #realserver的狀態監測設置部分單位秒 connect_timeout 10 #鏈接超時爲10秒 retry 3 #重連次數 delay_before_retry 3 #重試間隔 connect_port 6443 #鏈接端口爲6443,要和上面的保持一致 } } real_server 172.27.34.37 6443 { #配置服務器節點1,須要指定real server的真實IP地址和端口 weight 10 #設置權重,數字越大權重越高 TCP_CHECK { #realserver的狀態監測設置部分單位秒 connect_timeout 10 #鏈接超時爲10秒 retry 3 #重連次數 delay_before_retry 3 #重試間隔 connect_port 6443 #鏈接端口爲6443,要和上面的保持一致 } } }
lvs-keepalived02配置以下:
[root@lvs-keepalived02 ~]# more /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { router_id lvs-keepalived02 #router_id 機器標識,一般爲hostname,但不必定非得是hostname。故障發生時,郵件通知會用到。 } vrrp_instance VI_1 { #vrrp實例定義部分 state BACKUP #設置lvs的狀態,MASTER和BACKUP兩種,必須大寫 interface ens160 #設置對外服務的接口 virtual_router_id 100 #設置虛擬路由標示,這個標示是一個數字,同一個vrrp實例使用惟一標示 priority 90 #定義優先級,數字越大優先級越高,在一個vrrp——instance下,master的優先級必須大於backup advert_int 1 #設定master與backup負載均衡器之間同步檢查的時間間隔,單位是秒 authentication { #設置驗證類型和密碼 auth_type PASS #主要有PASS和AH兩種 auth_pass 1111 #驗證密碼,同一個vrrp_instance下MASTER和BACKUP密碼必須相同 } virtual_ipaddress { #設置虛擬ip地址,能夠設置多個,每行一個 172.27.34.222 } } virtual_server 172.27.34.222 6443 { #設置虛擬服務器,須要指定虛擬ip和服務端口 delay_loop 6 #健康檢查時間間隔 lb_algo wrr #負載均衡調度算法 lb_kind DR #負載均衡轉發規則 #persistence_timeout 50 #設置會話保持時間,對動態網頁很是有用 protocol TCP #指定轉發協議類型,有TCP和UDP兩種 real_server 172.27.34.35 6443 { #配置服務器節點1,須要指定real server的真實IP地址和端口 weight 10 #設置權重,數字越大權重越高 TCP_CHECK { #realserver的狀態監測設置部分單位秒 connect_timeout 10 #鏈接超時爲10秒 retry 3 #重連次數 delay_before_retry 3 #重試間隔 connect_port 6443 #鏈接端口爲6443,要和上面的保持一致 } } real_server 172.27.34.36 6443 { #配置服務器節點1,須要指定real server的真實IP地址和端口 weight 10 #設置權重,數字越大權重越高 TCP_CHECK { #realserver的狀態監測設置部分單位秒 connect_timeout 10 #鏈接超時爲10秒 retry 3 #重連次數 delay_before_retry 3 #重試間隔 connect_port 6443 #鏈接端口爲6443,要和上面的保持一致 } } real_server 172.27.34.37 6443 { #配置服務器節點1,須要指定real server的真實IP地址和端口 weight 10 #設置權重,數字越大權重越高 TCP_CHECK { #realserver的狀態監測設置部分單位秒 connect_timeout 10 #鏈接超時爲10秒 retry 3 #重連次數 delay_before_retry 3 #重試間隔 connect_port 6443 #鏈接端口爲6443,要和上面的保持一致 } } }
[root@master01 ~]# ifconfig ens160:2 172.27.34.222 netmask 255.255.255.0 down
master01上去掉初始化使用的ip 172.27.34.222
lvs-keepalived01和lvs-keepalived02都啓動keepalived並設置爲開機啓動
[root@lvs-keepalived01 ~]# service keepalived start Redirecting to /bin/systemctl start keepalived.service [root@lvs-keepalived01 ~]# systemctl enable keepalived Created symlink from /etc/systemd/system/multi-user.target.wants/keepalived.service to /usr/lib/systemd/system/keepalived.service.
[root@lvs-keepalived01 ~]# ip a
此時vip在lvs-keepalived01上
control plane都執行本操做。
打開control plane所在服務器的「路由」功能、關閉「ARP查詢」功能並設置迴環ip,三臺control plane配置相同,以下:
[root@master01 ~]# cd /etc/rc.d/init.d/ [root@master01 init.d]# more realserver.sh #!/bin/bash SNS_VIP=172.27.34.222 case "$1" in start) ifconfig lo:0 $SNS_VIP netmask 255.255.255.255 broadcast $SNS_VIP /sbin/route add -host $SNS_VIP dev lo:0 echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce sysctl -p >/dev/null 2>&1 echo "RealServer Start OK" ;; stop) ifconfig lo:0 down route del $SNS_VIP >/dev/null 2>&1 echo "0" >/proc/sys/net/ipv4/conf/lo/arp_ignore echo "0" >/proc/sys/net/ipv4/conf/lo/arp_announce echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce echo "RealServer Stoped" ;; *) echo "Usage: $0 {start|stop}" exit 1 esac exit 0
此腳本用於control plane節點綁定 VIP ,並抑制響應 VIP 的 ARP 請求。這樣作的目的是爲了避免讓關於 VIP 的 ARP 廣播時,節點服務器應答( 由於control plane節點都綁定了 VIP ,若是不作設置它們會應答,就會亂套 )。
在全部control plane節點執行realserver.sh腳本:
[root@master01 init.d]# chmod u+x realserver.sh [root@master01 init.d]# /etc/rc.d/init.d/realserver.sh start RealServer Start OK
給realserver.sh腳本授予執行權限並運行realserver.sh腳本
[root@master01 init.d]# sed -i '$a /etc/rc.d/init.d/realserver.sh start' /etc/rc.d/rc.local [root@master01 init.d]# chmod u+x /etc/rc.d/rc.local
[root@client ~]# 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=1 repo_gpgcheck=1 gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg EOF
[root@client ~]# yum clean all [root@client ~]# yum -y makecache
[root@client ~]# yum install -y kubectl-1.16.4
安裝版本與集羣版本保持一致
[root@client ~]# yum -y install bash-completion
[root@client ~]# source /etc/profile.d/bash_completion.sh
[root@client ~]# mkdir -p /etc/kubernetes [root@client ~]# scp 172.27.34.35:/etc/kubernetes/admin.conf /etc/kubernetes/ [root@client ~]# echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> ~/.bash_profile [root@client ~]# source .bash_profile
[root@master01 ~]# echo "source <(kubectl completion bash)" >> ~/.bash_profile [root@master01 ~]# source .bash_profile
[root@client ~]# kubectl get nodes [root@client ~]# kubectl get cs [root@client ~]# kubectl cluster-info [root@client ~]# kubectl get po -o wide -n kube-system
本節內容都在client節點完成。
[root@client ~]# wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.0-beta8/aio/deploy/recommended.yaml
若是鏈接超時,能夠多試幾回。recommended.yaml已上傳,也能夠在文末下載。
[root@client ~]# sed -i 's/kubernetesui/registry.cn-hangzhou.aliyuncs.com\/loong576/g' recommended.yaml
因爲默認的鏡像倉庫網絡訪問不通,故改爲阿里鏡像
[root@client ~]# sed -i '/targetPort: 8443/a\ \ \ \ \ \ nodePort: 30001\n\ \ type: NodePort' recommended.yaml
配置NodePort,外部經過https://NodeIp:NodePort 訪問Dashboard,此時端口爲30001
[root@client ~]# cat >> recommended.yaml << EOF --- # ------------------- dashboard-admin ------------------- # apiVersion: v1 kind: ServiceAccount metadata: name: dashboard-admin namespace: kubernetes-dashboard --- apiVersion: rbac.authorization.k8s.io/v1beta1 kind: ClusterRoleBinding metadata: name: dashboard-admin subjects: - kind: ServiceAccount name: dashboard-admin namespace: kubernetes-dashboard roleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole name: cluster-admin
建立超級管理員的帳號用於登陸Dashboard
[root@client ~]# kubectl apply -f recommended.yaml
[root@client ~]# kubectl get all -n kubernetes-dashboard
[root@client ~]# kubectl describe secrets -n kubernetes-dashboard dashboard-admin
令牌爲:
eyJhbGciOiJSUzI1NiIsImtpZCI6Ii1SOU1pNGswQnJCVUtCaks2TlBnMGxUdGRSdTlPS0s0MjNjUkdlNzFRVXMifQ.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.WJPzxkAGYjtq556d3HuXNh6g0sDYm2h6U_FsPDvvfhquYSccPGJ1UzX-lKxhPYyCegc603D7yFCc9zQOzpONttkue3rGdOz8KePOAHCUX7Xp_yTcJg15BPxQDDny6Lebu0fFXh_fpbU2_35nG28lRjiwKG3mV3O5uHdX5nk500RBmLkw3F054ww66hgFBfTH2HVDi1jOlAKWC0xatdxuqp2JkMqiBCZ_8Zwhi66EQYAMT1xu8Sn5-ur_6QsgaNNYhCeNxqHUiEFIZdLNu8QAnsKJJuhxxXd2KhIF6dwMvvOPG1djKCKSyNRn-SGILDucu1_6FoBG1DiNcIr90cPAtA
請使用火狐瀏覽器訪問:https://control plane ip:30001,即https://172.27.34.35/36/37:30001/
接受風險 經過令牌方式登陸
登陸的首頁顯示
切換到命名空間kubernetes-dashboard,查看資源。
Dashboard提供了能夠實現集羣管理、工做負載、服務發現和負載均衡、存儲、字典配置、日誌視圖等功能。
爲了豐富dashboard的統計數據和圖表,能夠安裝heapster組件。heapster組件實踐詳見:k8s實踐(十一):heapster+influxdb+grafana實現kubernetes集羣監
經過ipvsadm查看apiserver所在節點,經過leader-elect查看scheduler和controller-manager所在節點:
在lvs-keepalived01上執行ipvsadm查看apiserver轉發到的服務器
[root@lvs-keepalived01 ~]# ipvsadm -ln IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP 172.27.34.222:6443 wrr -> 172.27.34.35:6443 Route 10 2 0 -> 172.27.34.36:6443 Route 10 2 0 -> 172.27.34.37:6443 Route 10 2 0
在client節點上查看controller-manager和scheduler組件所在節點
[root@client ~]# kubectl get endpoints kube-controller-manager -n kube-system -o yaml |grep holderIdentity control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"master01_0a2bcea9-d17e-405b-8b28-5059ca434144","leaseDurationSeconds":15,"acquireTime":"2020-01-19T03:07:51Z","renewTime":"2020-01-19T04:40:20Z","leaderTransitions":2}' [root@client ~]# kubectl get endpoints kube-scheduler -n kube-system -o yaml |grep holderIdentity control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"master01_c284cee8-57cf-46e7-a578-6c0a10aedb37","leaseDurationSeconds":15,"acquireTime":"2020-01-19T03:07:51Z","renewTime":"2020-01-19T04:40:30Z","leaderTransitions":2}'
組件名 | 所在節點 |
---|---|
apiserver | master0一、master0二、master03 |
controller-manager | master01 |
scheduler | master01 |
關閉master01,模擬宕機
[root@master01 ~]# init 0
lvs-keepalived01上查看apiserver節點連接狀況
[root@lvs-keepalived01 ~]# ipvsadm -ln IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP 172.27.34.222:6443 wrr -> 172.27.34.36:6443 Route 10 4 0 -> 172.27.34.37:6443 Route 10 2 0
發現master01的apiserver被移除集羣,即訪問172.27.34.222:64443時不會被調度到master01
client節點上再次運行查看controller-manager和scheduler命令
[root@client ~]# kubectl get endpoints kube-controller-manager -n kube-system -o yaml |grep holderIdentity control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"master03_9481b109-f236-432a-a2cb-8d0c27417396","leaseDurationSeconds":15,"acquireTime":"2020-01-19T04:42:22Z","renewTime":"2020-01-19T04:45:45Z","leaderTransitions":3}' [root@client ~]# kubectl get endpoints kube-scheduler -n kube-system -o yaml |grep holderIdentity control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"master03_6d84981b-3ab9-4a00-a86a-47bd2f5c7729","leaseDurationSeconds":15,"acquireTime":"2020-01-19T04:42:23Z","renewTime":"2020-01-19T04:45:48Z","leaderTransitions":3}' [root@client ~]#
controller-manager和scheduler都被切換到master03節點
組件名 | 所在節點 |
---|---|
apiserver | master0二、master03 |
controller-manager | master03 |
scheduler | master03 |
全部功能性測試都在client節點完成。
[root@client ~]# kubectl get nodes NAME STATUS ROLES AGE VERSION master01 NotReady master 22h v1.16.4 master02 Ready master 22h v1.16.4 master03 Ready master 22h v1.16.4 work01 Ready <none> 22h v1.16.4 work02 Ready <none> 22h v1.16.4 work03 Ready <none> 22h v1.16.4
master01狀態爲NotReady
[root@client ~]# more nginx-master.yaml apiVersion: apps/v1 #描述文件遵循extensions/v1beta1版本的Kubernetes API kind: Deployment #建立資源類型爲Deployment metadata: #該資源元數據 name: nginx-master #Deployment名稱 spec: #Deployment的規格說明 selector: matchLabels: app: nginx replicas: 3 #指定副本數爲3 template: #定義Pod的模板 metadata: #定義Pod的元數據 labels: #定義label(標籤) app: nginx #label的key和value分別爲app和nginx spec: #Pod的規格說明 containers: - name: nginx #容器的名稱 image: nginx:latest #建立容器所使用的鏡像 [root@client ~]# kubectl apply -f nginx-master.yaml deployment.apps/nginx-master created [root@client ~]# kubectl get po -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES nginx-master-75b7bfdb6b-9d66p 1/1 Running 0 20s 10.244.3.6 work01 <none> <none> nginx-master-75b7bfdb6b-h4bql 1/1 Running 0 20s 10.244.5.5 work03 <none> <none> nginx-master-75b7bfdb6b-zmc68 1/1 Running 0 20s 10.244.4.5 work02 <none> <none>
以新建pod nginx爲例測試集羣是否能正常對外提供服務。
在3節點的k8s集羣中,當有一個control plane節點宕機時,集羣各項功能不受影響。
在master01處於關閉狀態下,繼續關閉master02,測試集羣還可否正常對外服務。
[root@master02 ~]# init 0
[root@lvs-keepalived01 ~]# ipvsadm -ln IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP 172.27.34.222:6443 wrr -> 172.27.34.37:6443 Route 10 6 20
此時對集羣的訪問都轉到master03
[root@client ~]# kubectl get nodes The connection to the server 172.27.34.222:6443 was refused - did you specify the right host or port?
在3節點的k8s集羣中,當有兩個control plane節點同時宕機時,etcd集羣崩潰,整個k8s集羣也不能正常對外服務。
[root@client ~]# kubectl get nodes NAME STATUS ROLES AGE VERSION master01 Ready master 161m v1.16.4 master02 Ready master 144m v1.16.4 master03 Ready master 142m v1.16.4 work01 Ready <none> 137m v1.16.4 work02 Ready <none> 135m v1.16.4 work03 Ready <none> 134m v1.16.4
集羣內個節點運行正常
[root@lvs-keepalived01 ~]# ip a|grep 222 inet 172.27.34.222/32 scope global ens160
發現vip運行在lvs-keepalived01上
lvs-keepalived01:
[root@lvs-keepalived01 ~]# ipvsadm -ln IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP 172.27.34.222:6443 wrr -> 172.27.34.35:6443 Route 10 6 0 -> 172.27.34.36:6443 Route 10 0 0 -> 172.27.34.37:6443 Route 10 38 0
lvs-keepalived02:
[root@lvs-keepalived02 ~]# ipvsadm -ln IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP 172.27.34.222:6443 wrr -> 172.27.34.35:6443 Route 10 0 0 -> 172.27.34.36:6443 Route 10 0 0 -> 172.27.34.37:6443 Route 10 0 0
關閉lvs-keepalived01,模擬宕機
[root@lvs-keepalived01 ~]# init 0
[root@client ~]# kubectl get nodes NAME STATUS ROLES AGE VERSION master01 Ready master 166m v1.16.4 master02 Ready master 148m v1.16.4 master03 Ready master 146m v1.16.4 work01 Ready <none> 141m v1.16.4 work02 Ready <none> 139m v1.16.4 work03 Ready <none> 138m v1.16.4
集羣內個節點運行正常
[root@lvs-keepalived02 ~]# ip a|grep 222 inet 172.27.34.222/32 scope global ens160
發現vip已漂移至lvs-keepalived02
lvs-keepalived02:
[root@lvs-keepalived02 ~]# ipvsadm -ln IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP 172.27.34.222:6443 wrr -> 172.27.34.35:6443 Route 10 1 0 -> 172.27.34.36:6443 Route 10 4 0 -> 172.27.34.37:6443 Route 10 1 0
[root@client ~]# kubectl delete -f nginx-master.yaml deployment.apps "nginx-master" deleted [root@client ~]# kubectl get po -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES nginx-master-75b7bfdb6b-9d66p 0/1 Terminating 0 20m 10.244.3.6 work01 <none> <none> nginx-master-75b7bfdb6b-h4bql 0/1 Terminating 0 20m 10.244.5.5 work03 <none> <none> nginx-master-75b7bfdb6b-zmc68 0/1 Terminating 0 20m 10.244.4.5 work02 <none> <none> [root@client ~]# kubectl get po -o wide No resources found in default namespace.
刪除以前新建的pod nginx,成功刪除。
當lvs-keepalived集羣有一臺宕機時,對k8s集羣無影響,仍能正常對外提供服務。
本文全部腳本和配置文件已上傳github:lvs-keepalived-install-k8s-HA-cluster
單機版k8s集羣部署詳見:k8s實踐(一):Centos7.6部署k8s(v1.14.2)集羣
主備高可用版k8s集羣部署詳見:k8s實踐(十五):Centos7.6部署k8s v1.16.4高可用集羣(主備模式)