Kubernetes---高可用的 K8S 集群构建
⒈系统初始化
1.设置系统主机名以及 Host 文件的相互解析
hostnamectl set-hostname k8s-master01
2.安装依赖包
yum install -y conntrack ntpdate ntp ipvsadm ipset jq iptables curl sysstat libseccomp wget vim net-tools git
3.设置防火墙为Iptables 并设置空规则
systemctl stop firewalld && systemctl disable firewalld yum -y install iptables-services && systemctl start iptables && systemctl enable iptables && iptables -F && service iptables save
4.关闭SELINUX
swapoff -a && sed -i '/ swap / s/^\(.*\)$/#\1/g’ /etc/fstab setenforce 0 && sed -i 's/^SELINUX=.*/SELINUX=disabled/' /etc/selinux/config
5.调整内核参数，对于 K8S
cat > kubernetes.conf <<EOF net.bridge.bridge-nf-call-iptables=1 net.bridge.bridge-nf-call-ip6tables=1 net.ipv4.ip_forward=1 net.ipv4.tcp_tw_recycle=0 vm.swappiness=0 # 禁止使用 swap 空间，只有当系统 00M时才允许使用它 vm.overcommit_memory=1 # 不检查物理内存是否够用 vm.panic_on_oom=0 # 开启 00M fs.inotify.max_user_instances=8192 fs.inotify.max_user_watches=1048576 fs.file-max=52706963 fs.nr_open=52706963 net.ipv6.conf.all.disable_ipv6=1 net.netfilter.nf_conntrack_max=2310720 EOF cp kubernetes.conf /etc/sysctl.d/kubernetes.conf sysctl -p /etc/sysctl.d/kubernetes.conf
6.调整系统时区
# 设置系统时区为中国/上海 timedatectl set-timezone Asia/Shanghai #将当前的 UTC 时间写入硬件时钟 timedatectl set-local-rtc 0 # 重启依赖于系统时间的服务 systemctl restart rsyslog systemctl restart crond
7.关闭系统不需要服务
systemctl stop postfix && systemctl disable postfix
8.设置 rsyslogd 和 systemd journald
mkdir /var/log/journal #持久化保存日志的目录 mkdir /etc/systemd/journald.conf.d cat > /etc/systemd/journald.conf.d/99-prophet.conf <<E0F [Journal] # 持久化保存到磁盘 Storage=persistent # 压缩历史日志 Compress=yes SyncIntervalSec=5m RateLimitInterval=30s RateLimitBurst=1000 # 最大占用空间 10G SystemMaxUse=10G #单日志文件最大200M SystemMaxFileSize=200M # 日志保存时间2周 MaxRetentionSec=2week # 不将日志转发到 syslog ForwardToSyslog=no EOF systemctl restart systemd-journald
9.升级系统内核为4.44
CentOs7.x系统自带的3.10.x内核在在一些Bugs，导致运行的Docker、Kubernetes不稳定，例如:rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-3.el7.elrepo.noarch.rpm
rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-3.el7.elrepo.noarch.rpm # 安装完成后检查 /boot/grub2/grub.cfg 中对应内核 menuentry 中是否包含 initrd16 配置，如果没有，再安装 一次! yum --enablerepo=elrepo-kernel install -y kernel-lt #设置开机从新内核启动 grub2-set-default "CentOS Linux (4.4.182-1.el7.elrepo.x86_64) 7 (Core)" #重启后安装内核源文件 yum --enablerepo=elrepo-kernel install kernel-lt-devel-$(uname -r) kernel-lt-headers-$(uname -r)
10.关闭NUMA
cp /etc/default/grub{,.bak} vim /etc/default/grub #在 GRUB_CMDLINE_LINUX 一行添加`numa=off`参数，如下所示: diff /etc/default/grub.bak /etc/default/grub 6c6 < GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=centos/root rhgb quiet" --- > GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=centos/root rhgb quiet numa=off" cp /boot/grub2/grub.cfg{,.bak} grub2-mkconfig -o /boot/grub2/grub.cfg
⒉Kubeadm 部署安装
1.kube-proxy开启ipvs的前置条件
modprobe br_netfilter cat > /etc/sysconfig/modules/ipvs.modules <<EOF #!/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 && bash /etc/sysconfig/modules/ipvs.modules && lsmod | grep -e ip_vs -e nf_conntrack_ipv4
2.安装Docker软件
yum install -y yum-utils device-mapper-persistent-data lvm2 yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo yum update -y && yum install -y docker-ce # 创建 /etc/docker 目录 mkdir /etc/docker #配置 daemon. cat > /etc/docker/daemon.json <<EOF { "exec-opts": ["native.cgroupdriver=systemd"], "log-driver": "json-file", "log-opts": { "max-size"："100m" } } EOF mkdir -p /etc/systemd/system/docker.service.d #重启docker服务 systemctl daemon-reload && systemctl restart docker && systemctl enable docker
3.在主节点启动 Haproxy与 Keepalived容器
导入脚本>运行>查看可用节点
4.安装Kubeadm （主从配置)
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 -y install kubeadm-1.15.1 kubectl-1.15.1 kubelet-1.15.1 systemctl enable kubelet.service
5.初始化主节点
kubeadm config print init-defaults > kubeadm-config.yaml kubeadm init --config=kubeadm-config.yaml --experimental-upload-certs | tee kubeadm-init.log
6.加入主节点以及其余工作节点
执行安装日志中的加入命令即可
7.Etcd 集群状态查看
kubectl -n kube-system exec etcd-k8s-master01 -- etcdctl \ --endpoints=https://192.168.92.10:2379 \ --ca-file=/etc/kubernetes/pki/etcd/ca.crt \ --cert-file=/etc/kubernetes/pki/etcd/server.crt \ --key-file=/etc/kubernetes/pki/etcd/server.key cluster-health kubectl get endpoints kube-controller-manager --namespace=kube-system -o yaml kubectl get endpoints kube-scheduler --namespace=kube-system -o yaml
8.部署网络
kubectl apply -f kube-flannel.yml
