kubeadm安裝k8s 1.15版
前提:
1、安裝 k8s 的節點必須是大於 1 核心的 CPU
2、阿里雲的repo 和base源
curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo
curl -o /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo
1、設置系統主機名以及host解析
hostnamectl set-hostname k8s-master
10.0.0.20 k8s-node01
10.0.0.21 k8s-node02
10.0.0.10 k8s-master
2、安裝依賴包
yum install -y conntrack ntpdate ntp ipvsadmin ipset jq iptables curl sysstat libseccomp wget vim net-tools git
3、設置防火牆爲 Iptables 並設置空規則
systemctl stop firewalld && systemctl disable firewalld
yum -y install iptables-services && systemctl start iptables && systemctl enable iptables && iptables -F && service iptables save
4、關閉selinux 關閉swap
開啓虛擬內存時 如果pod在swap中運行 那麼kubernetes出現報錯
swapoff -a && sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab
setenforce 0 && sed -i 's/^SELINUX=.*/SELINUX=disabled/' /etc/selinux/config
5、調整內核參數,對於 K8S
cat > kubernetes.conf <<EOF
net.bridge.bridge-nf-call-iptables=1 #開啓網橋模式
net.bridge.bridge-nf-call-ip6tables=1 #開啓網橋模式
net.ipv4.ip_forward=1
net.ipv4.tcp_tw_recycle=0
vm.swappiness=0 # 禁止使用 swap 空間,只有當系統 OOM 時才允許使用它
vm.overcommit_memory=1 # 不檢查物理內存是否夠用
vm.panic_on_oom=0 # 開啓 OOM
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 #關閉ipv6
net.netfilter.nf_conntrack_max=2310720
EOF
cp kubernetes.conf /etc/sysctl.d/kubernetes.conf 開機調用
sysctl -p /etc/sysctl.d/kubernetes.conf 立刻生效
6、調整系統時區
# 設置系統時區爲 中國/上海
timedatectl set-timezone Asia/Shanghai
# 將當前的 UTC 時間寫入硬件時鐘
timedatectl set-local-rtc 0
# 重啓依賴於系統時間的服務
systemctl restart rsyslog
systemctl restart crond
7、關閉系統不需要服務
systemctl stop postfix && systemctl disable postfix
8、設置 rsyslogd 和 systemd journald
使用日誌爲 journald 方式
mkdir /var/log/journal # 持久化保存日誌的目錄
mkdir /etc/systemd/journald.conf.d 創建配置文件存放目錄
創建journal 的日誌配置文件
cat > /etc/systemd/journald.conf.d/99-prophet.conf <<EOF
[Journal]
# 持久化保存到磁盤
Storage=persistent
# 壓縮歷史日誌
Compress=yes
SyncIntervalSec=5m
RateLimitInterval=30s
RateLimitBurst=1000
# 最大佔用空間 10G
SystemMaxUse=10G
# 單日誌文件最大 200M
SystemMaxFileSize=200M
# 日誌保存時間 2 周
MaxRetentionSec=2week
# 不將日誌轉發到 syslog
ForwardToSyslog=no
EOF
9、重啓服務
systemctl restart systemd-journald
10、升級系統內核爲 4.44
CentOS 7.x 系統自帶的 3.10.x 內核存在一些 Bugs,導致運行的 Docker、Kubernetes 不穩定,例如: rpm -Uvh
http://www.elrepo.org/elrepo-release-7.0-3.el7.elrepo.noarch.rpm
升級
rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-3.el7.elrepo.noarch.rpm
# 安裝完成後檢查 /boot/grub2/grub.cfg 中對應內核 menuentry 中是否包含 initrd16 配置,如果沒有,再安裝
一次!
yum --enablerepo=elrepo-kernel install -y kernel-lt
# 設置開機從新內核啓動
grub2-set-default 'CentOS Linux (4.4.226-1.el7.elrepo.x86_64) 7 (Core)' && reboot
uname -r
11、kube-proxy開啓ipvs的前置條件
修改調度方式爲ipvs,解決pod和service的調度方式
modprobe br_netfilter 加載模塊
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
12、安裝 Docker 軟件
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
systemctl restart docker && systemctl enable docker
uname -r
## 創建 /etc/docker 目錄
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
13、 # 重啓docker服務
systemctl daemon-reload && systemctl restart docker && systemctl enable docker
14、安裝 Kubeadm (主從配置)
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
導入鏡像
每個節點都需要導入鏡像
鏡像下載
鏈接:https://pan.baidu.com/s/18UoPtPGM4XGZIpUYMW-zaQ
提取碼:lcrb
15、初始化主節點
kubeadm config print init-defaults > kubeadm-config.yaml
修改爲一下內容:
apiVersion: kubeadm.k8s.io/v1beta2
bootstrapTokens:
- groups:
- system:bootstrappers:kubeadm:default-node-token
token: abcdef.0123456789abcdef
ttl: 24h0m0s
usages:
- signing
- authentication
kind: InitConfiguration
localAPIEndpoint:
advertiseAddress: 10.0.0.10
bindPort: 6443
nodeRegistration:
criSocket: /var/run/dockershim.sock
name: k8s-master
taints:
- effect: NoSchedule
key: node-role.kubernetes.io/master
---
apiServer:
timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager: {}
dns:
type: CoreDNS
etcd:
local:
dataDir: /var/lib/etcd
imageRepository: k8s.gcr.io
kind: ClusterConfiguration
kubernetesVersion: v1.15.1
networking:
dnsDomain: cluster.local
podSubnet: "10.244.0.0/16"
serviceSubnet: 10.96.0.0/12
scheduler: {}
---
apiVersion: kubeproxy.config.k8s.io/v1alpha1
kind: KubeProxyConfiguration
featureGates:
SupportIPVSProxyMode: true
mode: ipvs
kubeadm init --config=kubeadm-config.yaml --experimental-upload-certs | tee kubeadm-init.log
安裝kubernetes日誌文件解釋:
[init] Using Kubernetes version: v1.15.1 版本信息
[preflight] Running pre-flight checks 檢測當前運行環境
[preflight] Pulling images required for setting up a Kubernetes cluster 下載鏡像
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env" 存放kubernetes的環境變量
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml" kubernetes的配置文件
[certs] Using certificateDir folder "/etc/kubernetes/pki" 存放kubernetes的證書
[certs] apiserver serving cert is signed for DNS names [k8s-master kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 10.0.0.10]
設置默認的dns
[certs] Generating "front-proxy-ca" certificate and key 密鑰的生成
[certs] etcd/server serving cert is signed for DNS names [k8s-master localhost] and IPs [10.0.0.10 127.0.0.1 ::1] DNS的名稱和地址
[kubeconfig] Using kubeconfig folder "/etc/kubernetes"配置文件存放位置
初始化後的操作
mkdir -p $HOME/.kube 當前家目錄下創建.kube的目錄
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config 拷貝管理員的配置文件到.kube
sudo chown $(id -u):$(id -g) $HOME/.kube/config 賦予屬主屬組的權限
此時查看節點信息
[root@k8s-master ~]# kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master NotReady master 9m4s v1.15.1
出現 NotReady 狀態的原因是 kubernetes需要扁平化的網絡,構建flannel網絡
加入主節點以及其餘工作節點
執行安裝日誌中的加入命令即可
16、部署網絡
/root/install-k8s/plugin/flannel
cd /root/install-k8s/plugin/flannel
wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
下載下來之後(什麼都不需要改)進行創建flannel網絡
kubectl create -f kube-flannel.yml
kubectl get pod -n kube-system 查看是否執行成功
kubectl get node 再次查看 發現狀態變爲了Ready
kubectl get pod -n kube-system -o wide 查看
在node節點執行日誌提示的加入信息
kubectl get node 全部都變爲了Ready
kubectl get pod -n kube-system -w 持續查看
搭建完成
[root@k8s-master ~]# kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master Ready master 26m v1.15.1
k8s-node01 Ready <none> 7m10s v1.15.1
k8s-node02 Ready <none> 7m7s v1.15.1