集群方案:
- 发行版:CentOS 7
- 容器运行时
- 内核: 4.18.12-1.el7.elrepo.x86_64
- 版本:Kubernetes: 1.14.0
- 网络方案: Calico
- kube-proxy mode: IPVS
- master高可用方案:HAProxy keepalived LVS
- DNS插件: CoreDNS
- metrics插件:metrics-server
- 界面:kubernetes-dashboard
Kubernetes集群搭建
Host Name | Role | IP |
---|---|---|
master1 | master1 | 192.168.56.103 |
master2 | master2 | 192.168.56.104 |
master3 | master3 | 192.168.56.105 |
node1 | node1 | 192.168.56.106 |
node2 | node2 | 192.168.56.107 |
node3 | node3 | 192.168.56.108 |
1、离线安装包准备(基于能够访问外网的服务器下载相应安装包)
# 设置yum缓存路径,cachedir 缓存路径 keepcache=1保持安装包在软件安装之后不删除 cat /etc/yum.conf [main] cachedir=/home/yum keepcache=1 ... # 安装ifconfig yum install net-tools -y # 时间同步 yum install -y ntpdate # 安装docker(建议19.8.06) yum install -y yum-utils device-mapper-persistent-data lvm2 yum-config-manager \ --add-repo \ https://download.docker.com/linux/centos/docker-ce.repo yum makecache fast ## 列出Docker版本 yum list docker-ce --showduplicates | sort -r ## 安装指定版本 sudo yum install docker-ce-<VERSION_STRING> # 安装文件管理器,XShell可通过rz sz命令上传或者下载服务器文件 yum intall lrzsz -y # 安装keepalived、haproxy yum install -y socat keepalived ipvsadm haproxy # 安装kubernetes相关组件 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 yum install -y kubelet kubeadm kubectl ebtables # 其他软件安装 yum install wget ...
2、节点系统配置
- 关闭SELinux、防火墙
systemctl stop firewalld systemctl disable firewalld setenforce 0 sed -i "s/SELINUX=enforcing/SELINUX=disabled/g" /etc/selinux/config
- 关闭系统的Swap(Kubernetes 1.8开始要求)
swapoff -a yes | cp /etc/fstab /etc/fstab_bak cat /etc/fstab_bak |grep -v swap > /etc/fstab
- 配置L2网桥在转发包时会被iptables的FORWARD规则所过滤,该配置被CNI插件需要,更多信息请参考Network Plugin Requirements
echo """ vm.swappiness = 0 net.bridge.bridge-nf-call-ip6tables = 1 net.bridge.bridge-nf-call-iptables = 1 """ > /etc/sysctl.conf sysctl -p
centos7添加bridge-nf-call-ip6tables出现No such file or directory,简单来说就是执行一下 modprobe br_netfilter
- 同步时间
ntpdate -u ntp.api.bz
- 升级内核到最新(已准备内核离线安装包,可选)centos7 升级内核
grub2-set-default 0 && grub2-mkconfig -o /etc/grub2.cfg grubby --default-kernel grubby --args="user_namespace.enable=1" --update-kernel="$(grubby --default-kernel)"
- 重启系统,确认内核版本后,开启IPVS(如果未升级内核,去掉ip_vs_fo)
uname -a cat > /etc/sysconfig/modules/ipvs.modules <<EOF #!/bin/bash ipvs_modules="ip_vs ip_vs_lc ip_vs_wlc ip_vs_rr ip_vs_wrr ip_vs_lblc ip_vs_lblcr ip_vs_dh ip_vs_sh ip_vs_fo ip_vs_nq ip_vs_sed ip_vs_ftp nf_conntrack" for kernel_module in \${ipvs_modules}; do /sbin/modinfo -F filename \${kernel_module} > /dev/null 2>&1 if [ $? -eq 0 ]; then /sbin/modprobe \${kernel_module} fi done EOF chmod 755 /etc/sysconfig/modules/ipvs.modules && bash /etc/sysconfig/modules/ipvs.modules && lsmod | grep ip_vs
执行sysctl -p报错可执行modprobe br_netfilter,请参考centos7添加bridge-nf-call-ip6tables出现No such file or directory
- 所有机器需要设定/etc/sysctl.d/k8s.conf的系统参数
# https://github.com/moby/moby/issues/31208 # ipvsadm -l --timout # 修复ipvs模式下长连接timeout问题 小于900即可 cat <<EOF > /etc/sysctl.d/k8s.conf net.ipv4.tcp_keepalive_time = 600 net.ipv4.tcp_keepalive_intvl = 30 net.ipv4.tcp_keepalive_probes = 10 net.ipv6.conf.all.disable_ipv6 = 1 net.ipv6.conf.default.disable_ipv6 = 1 net.ipv6.conf.lo.disable_ipv6 = 1 net.ipv4.neigh.default.gc_stale_time = 120 net.ipv4.conf.all.rp_filter = 0 net.ipv4.conf.default.rp_filter = 0 net.ipv4.conf.default.arp_announce = 2 net.ipv4.conf.lo.arp_announce = 2 net.ipv4.conf.all.arp_announce = 2 net.ipv4.ip_forward = 1 net.ipv4.tcp_max_tw_buckets = 5000 net.ipv4.tcp_syncookies = 1 net.ipv4.tcp_max_syn_backlog = 1024 net.ipv4.tcp_synack_retries = 2 net.bridge.bridge-nf-call-ip6tables = 1 net.bridge.bridge-nf-call-iptables = 1 net.netfilter.nf_conntrack_max = 2310720 fs.inotify.max_user_watches=89100 fs.may_detach_mounts = 1 fs.file-max = 52706963 fs.nr_open = 52706963 net.bridge.bridge-nf-call-arptables = 1 vm.swappiness = 0 vm.overcommit_memory=1 vm.panic_on_oom=0 EOF sysctl --system
- 设置开机启动
# 启动docker sed -i "13i ExecStartPost=/usr/sbin/iptables -P FORWARD ACCEPT" /usr/lib/systemd/system/docker.service systemctl daemon-reload systemctl enable docker systemctl start docker # 设置kubelet开机启动 systemctl enable kubelet systemctl enable keepalived systemctl enable haproxy
- 设置免密登录
# 1、三次回车后,密钥生成完成 ssh-keygen # 2、拷贝密钥到其他节点 ssh-copy-id -i ~/.ssh/id_rsa.pub 用户名字@192.168.x.xxx
**、 Kubernetes要求集群中所有机器具有不同的Mac地址、产品uuid、Hostname。
3、keepalived+haproxy配置
cd ~/ # 创建集群信息文件 echo """ CP0_IP=10.130.29.80 CP1_IP=10.130.29.81 CP2_IP=10.130.29.82 VIP=10.130.29.83 NET_IF=eth0 CIDR=10.244.0.0/16 """ > ./cluster-info bash -c "$(curl -fsSL https://raw.githubusercontent.com/hnbcao/kubeadm-ha-master/v1.14.0/keepalived-haproxy.sh)"
4、部署HA Master
HA Master的部署过程已经自动化,请在master-1上执行如下命令,并注意修改IP;
脚本主要执行三步:
1)、重置kubelet设置
kubeadm reset -f rm -rf /etc/kubernetes/pki/
2)、编写节点配置文件并初始化master1的kubelet
echo """ apiVersion: kubeadm.k8s.io/v1beta1 kind: ClusterConfiguration kubernetesVersion: v1.13.0 controlPlaneEndpoint: "${VIP}:8443" maxPods: 100 networkPlugin: cni imageRepository: registry.aliyuncs.com/google_containers apiServer: certSANs: - ${CP0_IP} - ${CP1_IP} - ${CP2_IP} - ${VIP} networking: # This CIDR is a Calico default. Substitute or remove for your CNI provider. podSubnet: ${CIDR} --- apiVersion: kubeproxy.config.k8s.io/v1alpha1 kind: KubeProxyConfiguration mode: ipvs """ > /etc/kubernetes/kubeadm-config.yaml kubeadm init --config /etc/kubernetes/kubeadm-config.yaml mkdir -p $HOME/.kube cp -f /etc/kubernetes/admin.conf ${HOME}/.kube/config
- 关于默认网关问题,如果有多张网卡,需要先将默认网关切换到集群使用的那张网卡上,否则可能会出现etcd无法连接等问题。(应用我用的虚拟机,有一张网卡无法做到各个节点胡同;route查看当前网关信息,route del default删除默认网关,route add default enth0设置默认网关enth0为网卡名)
3)、拷贝相关证书到master2、master3
for index in 1 2; do ip=${IPS[${index}]} ssh $ip "mkdir -p /etc/kubernetes/pki/etcd; mkdir -p ~/.kube/" scp /etc/kubernetes/pki/ca.crt $ip:/etc/kubernetes/pki/ca.crt scp /etc/kubernetes/pki/ca.key $ip:/etc/kubernetes/pki/ca.key scp /etc/kubernetes/pki/sa.key $ip:/etc/kubernetes/pki/sa.key scp /etc/kubernetes/pki/sa.pub $ip:/etc/kubernetes/pki/sa.pub scp /etc/kubernetes/pki/front-proxy-ca.crt $ip:/etc/kubernetes/pki/front-proxy-ca.crt scp /etc/kubernetes/pki/front-proxy-ca.key $ip:/etc/kubernetes/pki/front-proxy-ca.key scp /etc/kubernetes/pki/etcd/ca.crt $ip:/etc/kubernetes/pki/etcd/ca.crt scp /etc/kubernetes/pki/etcd/ca.key $ip:/etc/kubernetes/pki/etcd/ca.key scp /etc/kubernetes/admin.conf $ip:/etc/kubernetes/admin.conf scp /etc/kubernetes/admin.conf $ip:~/.kube/config ssh ${ip} "${JOIN_CMD} --experimental-control-plane" done
4)、master2、master3加入节点
JOIN_CMD=`kubeadm token create --print-join-command` ssh ${ip} "${JOIN_CMD} --experimental-control-plane"
完整脚本:
# 部署HA master bash -c "$(curl -fsSL https://raw.githubusercontent.com/hnbcao/kubeadm-ha-master/v1.14.0/kube-ha.sh)"
5、加入节点
- 各个节点需要配置keepalived 和 haproxy
#/etc/haproxy/haproxy.cfg global log 127.0.0.1 local2 chroot /var/lib/haproxy pidfile /var/run/haproxy.pid maxconn 4000 user haproxy group haproxy daemon stats socket /var/lib/haproxy/stats defaults mode tcp log global option tcplog option dontlognull option redispatch retries 3 timeout queue 1m timeout connect 10s timeout client 1m timeout server 1m timeout check 10s maxconn 3000 listen stats mode http bind :10086 stats enable stats uri /admin?stats stats auth admin:admin stats admin if TRUE frontend k8s_https *:8443 mode tcp maxconn 2000 default_backend https_sri backend https_sri balance roundrobin server master1-api ${MASTER1_IP}:6443 check inter 10000 fall 2 rise 2 weight 1 server master2-api ${MASTER2_IP}:6443 check inter 10000 fall 2 rise 2 weight 1 server master3-api ${MASTER3_IP}:6443 check inter 10000 fall 2 rise 2 weight 1
#/etc/keepalived/keepalived.conf global_defs { router_id LVS_DEVEL } vrrp_script check_haproxy { script /etc/keepalived/check_haproxy.sh interval 3 } vrrp_instance VI_1 { state MASTER interface eth0 virtual_router_id 80 priority 100 advert_int 1 authentication { auth_type PASS auth_pass just0kk } virtual_ipaddress { ${VIP}/24 } track_script { check_haproxy } } }
注意两个配置中的{MASTER2 _ IP}, {VIP}需要替换为自己集群相应的IP地址
- 重启keepalived和haproxy
systemctl stop keepalived systemctl enable keepalived systemctl start keepalived systemctl stop haproxy systemctl enable haproxy systemctl start haproxy
- 节点加入命令获取
#master节点执行该命令,再在节点执行获取到的命令 kubeadm token create --print-join-command
6、结束安装
当前集群安装完毕,还需要安装cni插件,推荐使用calico,性能优于其他。
作者:hnbcao
链接:https://www.jianshu.com/p/a55e7d95a875
为什么每个节点都要装keepalive和haproxy?
keepalive和haproxy我了解的不是很深入,当时的情况是如果不安装的话,节点是访问不到虚拟IP的。另,集群是运行在阿里云环境上的。
有个疑问,keepalived 跨网段这个应该不行吧?
是文章的问题,keepalived+haproxy配置里面应该是
echo “””
CP0_IP=192.168.56.103
CP1_IP=192.168.56.104
CP2_IP=192.168.56.105
VIP=192.168.56.102
NET_IF=eth0
CIDR=10.244.0.0/16
“”” > ./cluster-info
etcd呢?
所有kubernetes组件都是在容器里运行,包括etcd。