注:该文来源李振良老师。
《部署一套完整的企业级K8s集群》
v1.20,kubeadm方式
作者信息 |
李振良(阿良),微信:xyz12366699 |
DevOps实战学院 |
|
说明 |
该文档有导航窗格,方便阅读,如果左侧没有显示,请检查word是否启用。 转载请注明作者,拒绝不道德行为! |
最后更新时间 |
2021-04-21 |
目录
1.1 生产环境可部署Kubernetes集群的两种方式.... 2
二、部署Nginx+Keepalived高可用负载均衡器.... 6
2.3 keepalived配置文件(Nginx Master).... 9
2.4 keepalived配置文件(Nginx Backup).... 10
2.7 Nginx+Keepalived高可用测试.... 12
四、安装Docker/kubeadm/kubelet【所有节点】.... 21
4.3 安装kubeadm,kubelet和kubectl.. 21
一、前置知识点
1.1 生产环境可部署Kubernetes集群的两种方式
目前生产部署Kubernetes集群主要有两种方式:
- kubeadm
Kubeadm是一个K8s部署工具,提供kubeadm init和kubeadm join,用于快速部署Kubernetes集群。
- 二进制包
从github下载发行版的二进制包,手动部署每个组件,组成Kubernetes集群。
这里采用kubeadm搭建集群。
kubeadm工具功能:
- kubeadm init:初始化一个Master节点
- kubeadm join:将工作节点加入集群
- kubeadm upgrade:升级K8s版本
- kubeadm token:管理 kubeadm join 使用的令牌
- kubeadm reset:清空 kubeadm init 或者 kubeadm join 对主机所做的任何更改
- kubeadm version:打印 kubeadm 版本
- kubeadm alpha:预览可用的新功能
1.2 准备环境
服务器要求:
- 建议最小硬件配置:2核CPU、2G内存、30G硬盘
- 服务器最好可以访问外网,会有从网上拉取镜像需求,如果服务器不能上网,需要提前下载对应镜像并导入节点
软件环境:
软件 |
版本 |
操作系统 |
CentOS7.8_x64 (mini) |
Docker |
19-ce |
Kubernetes |
1.20 |
服务器整体规划:
角色 |
IP |
其他单装组件 |
k8s-master1 |
192.168.16.80 |
docker,etcd,nginx,keepalived |
k8s-master2 |
192.168.16.81 |
docker,etcd,nginx,keepalived |
k8s-node1 |
192.168.16.82 |
docker,etcd |
负载均衡器对外IP |
192.168.16.88 (VIP) |
架构图:
1.3 操作系统初始化配置
# 关闭防火墙 systemctl stop firewalld systemctl disable firewalld # 关闭selinux sed -i 's/enforcing/disabled/' /etc/selinux/config # 永久 setenforce 0 # 临时 # 关闭swap swapoff -a # 临时 sed -ri 's/.*swap.*/#&/' /etc/fstab # 永久 # 根据规划设置主机名 hostnamectl set-hostname <hostname> # 在master添加hosts cat >> /etc/hosts << EOF 192.168.16.80 k8s-master01
192.168.16.81 k8s-master02
192.168.16.82 k8s-node01
192.168.16.83 k8s-node02
192.168.16.88 k8s-vip EOF # 将桥接的IPv4流量传递到iptables的链 cat > /etc/sysctl.d/k8s.conf << EOF net.bridge.bridge-nf-call-ip6tables = 1 net.bridge.bridge-nf-call-iptables = 1 EOF sysctl --system # 生效 # 时间同步 yum install ntpdate -y ntpdate time.windows.com
ntpdate cn.pool.ntp.org
crontab -l
0 5 * * * /usr/sbin/ntpdate -u cn.pool.ntp.org
[root@k8s-master01 ~]# systemctl enable ntpdate.service
二、部署Nginx+Keepalived高可用负载均衡器
Kubernetes作为容器集群系统,通过健康检查+重启策略实现了Pod故障自我修复能力,通过调度算法实现将Pod分布式部署,并保持预期副本数,根据Node失效状态自动在其他Node拉起Pod,实现了应用层的高可用性。
针对Kubernetes集群,高可用性还应包含以下两个层面的考虑:Etcd数据库的高可用性和Kubernetes Master组件的高可用性。 而kubeadm搭建的K8s集群,Etcd只起了一个,存在单点,所以我们这里会独立搭建一个Etcd集群。
Master节点扮演着总控中心的角色,通过不断与工作节点上的Kubelet和kube-proxy进行通信来维护整个集群的健康工作状态。如果Master节点故障,将无法使用kubectl工具或者API做任何集群管理。
Master节点主要有三个服务kube-apiserver、kube-controller-manager和kube-scheduler,其中kube-controller-manager和kube-scheduler组件自身通过选择机制已经实现了高可用,所以Master高可用主要针对kube-apiserver组件,而该组件是以HTTP API提供服务,因此对他高可用与Web服务器类似,增加负载均衡器对其负载均衡即可,并且可水平扩容。
kube-apiserver高可用架构图:
- Nginx是一个主流Web服务和反向代理服务器,这里用四层实现对apiserver实现负载均衡。
- Keepalived是一个主流高可用软件,基于VIP绑定实现服务器双机热备,在上述拓扑中,Keepalived主要根据Nginx运行状态判断是否需要故障转移(偏移VIP),例如当Nginx主节点挂掉,VIP会自动绑定在Nginx备节点,从而保证VIP一直可用,实现Nginx高可用。
注:为了节省机器,这里与K8s master节点机器复用。也可以独立于k8s集群之外部署,只要nginx与apiserver能通信就行。
2.1 安装软件包(主/备)
yum install epel-release -y
yum install nginx keepalived -y
2.2 Nginx配置文件(主/备一样)
cat > /etc/nginx/nginx.conf << "EOF" user nginx; worker_processes auto; error_log /var/log/nginx/error.log; pid /run/nginx.pid; include /usr/share/nginx/modules/*.conf; events { worker_connections 1024; } # 四层负载均衡,为两台Master apiserver组件提供负载均衡 stream { log_format main '$remote_addr $upstream_addr - [$time_local] $status $upstream_bytes_sent'; access_log /var/log/nginx/k8s-access.log main; upstream k8s-apiserver { server 192.168.16.80:6443; # Master1 APISERVER IP:PORT server 192.168.16.81:6443; # Master2 APISERVER IP:PORT } server { listen 16443; # 由于nginx与master节点复用,这个监听端口不能是6443,否则会冲突 proxy_pass k8s-apiserver; } } http { log_format main '$remote_addr - $remote_user [$time_local] "$request" ' '$status $body_bytes_sent "$http_referer" ' '"$http_user_agent" "$http_x_forwarded_for"'; access_log /var/log/nginx/access.log main; sendfile on; tcp_nopush on; tcp_nodelay on; keepalive_timeout 65; types_hash_max_size 2048; include /etc/nginx/mime.types; default_type application/octet-stream; server { listen 80 default_server; server_name _; location / { } } } EOF
2.3 keepalived配置文件(Nginx Master)
cat > /etc/keepalived/keepalived.conf << EOF global_defs { notification_email { [email protected] [email protected] [email protected] } notification_email_from [email protected] smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id NGINX_MASTER } vrrp_script check_nginx { script "/etc/keepalived/check_nginx.sh" } vrrp_instance VI_1 { state MASTER interface ens33 # 修改为实际网卡名 virtual_router_id 51 # VRRP 路由 ID实例,每个实例是唯一的 priority 100 # 优先级,备服务器设置 90 advert_int 1 # 指定VRRP 心跳包通告间隔时间,默认1秒 authentication { auth_type PASS auth_pass 1111 } # 虚拟IP virtual_ipaddress { 192.168.16.88/24 } track_script { check_nginx } } EOF
- vrrp_script:指定检查nginx工作状态脚本(根据nginx状态判断是否故障转移)
- virtual_ipaddress:虚拟IP(VIP)
准备上述配置文件中检查nginx运行状态的脚本:
cat > /etc/keepalived/check_nginx.sh << "EOF"
#!/bin/bash
count=$(ss -antp |grep 16443 |egrep -cv "grep|$$")
if [ "$count" -eq 0 ];then
exit 1
else
exit 0
fi
EOF
chmod +x /etc/keepalived/check_nginx.sh
2.4 keepalived配置文件(Nginx Backup)
cat > /etc/keepalived/keepalived.conf << EOF global_defs { notification_email { [email protected] [email protected] [email protected] } notification_email_from [email protected] smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id NGINX_BACKUP } vrrp_script check_nginx { script "/etc/keepalived/check_nginx.sh" } vrrp_instance VI_1 { state BACKUP interface ens33 virtual_router_id 51 # VRRP 路由 ID实例,每个实例是唯一的 priority 90 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.16.88/24 } track_script { check_nginx } } EOF
准备上述配置文件中检查nginx运行状态的脚本:
cat > /etc/keepalived/check_nginx.sh << "EOF"
#!/bin/bash
count=$(ss -antp |grep 16443 |egrep -cv "grep|$$")
if [ "$count" -eq 0 ];then
exit 1
else
exit 0
fi
EOF
chmod +x /etc/keepalived/check_nginx.sh
注:keepalived根据脚本返回状态码(0为工作正常,非0不正常)判断是否故障转移。
2.5 启动并设置开机启动
systemctl daemon-reload systemctl start nginx —— nginx启动不成功 systemctl start keepalived systemctl enable nginx systemctl enable keepalived
2.6 查看keepalived工作状态
ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether 00:0c:29:04:f7:2c brd ff:ff:ff:ff:ff:ff
inet 192.168.31.80/24 brd 192.168.31.255 scope global noprefixroute ens33
valid_lft forever preferred_lft forever
inet 192.168.31.88/24 scope global secondary ens33
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fe04:f72c/64 scope link
valid_lft forever preferred_lft forever
可以看到,在ens33网卡绑定了192.168.31.88 虚拟IP,说明工作正常。
2.7 Nginx+Keepalived高可用测试
关闭主节点Nginx,测试VIP是否漂移到备节点服务器。
在Nginx Master执行 pkill nginx
在Nginx Backup,ip addr命令查看已成功绑定VIP。
三、部署Etcd集群
如果你在学习中遇到问题或者文档有误可联系阿良~ 微信: xyz12366699
Etcd 是一个分布式键值存储系统,Kubernetes使用Etcd进行数据存储,kubeadm搭建默认情况下只启动一个Etcd Pod,存在单点故障,生产环境强烈不建议,所以我们这里使用3台服务器组建集群,可容忍1台机器故障,当然,你也可以使用5台组建集群,可容忍2台机器故障。
节点名称 |
IP |
etcd-1 |
192.168.16.80 |
etcd-2 |
192.168.16.81 |
etcd-3 |
192.168.16.82 |
注:为了节省机器,这里与K8s节点机器复用。也可以独立于k8s集群之外部署,只要apiserver能连接到就行。
3.1 准备cfssl证书生成工具
cfssl是一个开源的证书管理工具,使用json文件生成证书,相比openssl更方便使用。
找任意一台服务器操作,这里用Master节点。
[root@k8s-master01 ~]# cd /opt/
wget https://pkg.cfssl.org/R1.2/cfssl_linux-amd64
wget https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
wget https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64
chmod +x cfssl_linux-amd64 cfssljson_linux-amd64 cfssl-certinfo_linux-amd64
mv cfssl_linux-amd64 /usr/local/bin/cfssl
mv cfssljson_linux-amd64 /usr/local/bin/cfssljson
mv cfssl-certinfo_linux-amd64 /usr/bin/cfssl-certinfo
3.2 生成Etcd证书
1. 自签证书颁发机构(CA)
创建工作目录:
mkdir -p ~/etcd_tls
cd ~/etcd_tls
自签CA:
cat > ca-config.json << EOF
{
"signing": {
"default": {
"expiry": "87600h"
},
"profiles": {
"www": {
"expiry": "87600h",
"usages": [
"signing",
"key encipherment",
"server auth",
"client auth"
]
}
}
}
}
EOF
cat > ca-csr.json << EOF
{
"CN": "etcd CA",
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"L": "Beijing",
"ST": "Beijing"
}
]
}
EOF
生成证书:
cfssl gencert -initca ca-csr.json | cfssljson -bare ca -
会生成ca.pem和ca-key.pem文件。
2. 使用自签CA签发Etcd HTTPS证书
创建证书申请文件:
cat > server-csr.json << EOF
{
"CN": "etcd",
"hosts": [
"192.168.16.80",
"192.168.16.81",
"192.168.16.82"
],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"L": "BeiJing",
"ST": "BeiJing"
}
]
}
EOF
注:上述文件hosts字段中IP为所有etcd节点的集群内部通信IP,一个都不能少!为了方便后期扩容可以多写几个预留的IP。
生成证书:
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=www server-csr.json | cfssljson -bare server
会生成server.pem和server-key.pem文件。
3.3 从Github下载二进制文件
下载地址:https://github.com/etcd-io/etcd/releases/download/v3.4.9/etcd-v3.4.9-linux-amd64.tar.gz
3.4 部署Etcd集群
以下在节点1上操作,为简化操作,待会将节点1生成的所有文件拷贝到节点2和节点3。
1. 创建工作目录并解压二进制包
mkdir /opt/etcd/{bin,cfg,ssl} -p tar zxvf etcd-v3.4.9-linux-amd64.tar.gz mv etcd-v3.4.9-linux-amd64/{etcd,etcdctl} /opt/etcd/bin/
cat > /opt/etcd/cfg/etcd.conf << EOF
#[Member]
ETCD_NAME="etcd-1"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.16.80:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.16.80:2379"
#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.16.80:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.16.80:2379"
ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.16.80:2380,etcd-2=https://192.168.16.81:2380,etcd-3=https://192.168.16.82:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
EOF
- ETCD_NAME:节点名称,集群中唯一
- ETCDDATADIR:数据目录
- ETCDLISTENPEER_URLS:集群通信监听地址
- ETCDLISTENCLIENT_URLS:客户端访问监听地址
- ETCDINITIALADVERTISEPEERURLS:集群通告地址
- ETCDADVERTISECLIENT_URLS:客户端通告地址
- ETCDINITIALCLUSTER:集群节点地址
- ETCDINITIALCLUSTER_TOKEN:集群Token
- ETCDINITIALCLUSTER_STATE:加入集群的当前状态,new是新集群,existing表示加入已有集群
cat > /usr/lib/systemd/system/etcd.service << EOF
[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target
[Service]
Type=notify
EnvironmentFile=/opt/etcd/cfg/etcd.conf
ExecStart=/opt/etcd/bin/etcd \
--cert-file=/opt/etcd/ssl/server.pem \
--key-file=/opt/etcd/ssl/server-key.pem \
--peer-cert-file=/opt/etcd/ssl/server.pem \
--peer-key-file=/opt/etcd/ssl/server-key.pem \
--trusted-ca-file=/opt/etcd/ssl/ca.pem \
--peer-trusted-ca-file=/opt/etcd/ssl/ca.pem \
--logger=zap
Restart=on-failure
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
EOF
4. 拷贝刚才生成的证书
把刚才生成的证书拷贝到配置文件中的路径:
cp ~/etcd_tls/ca*pem ~/etcd_tls/server*pem /opt/etcd/ssl/
systemctl daemon-reload
systemctl start etcd
systemctl enable etcd
6. 将上面节点1所有生成的文件拷贝到节点2和节点3
scp -r /opt/etcd/ [email protected]:/opt/
scp /usr/lib/systemd/system/etcd.service [email protected]:/usr/lib/systemd/system/
scp -r /opt/etcd/ [email protected]:/opt/
scp /usr/lib/systemd/system/etcd.service [email protected]:/usr/lib/systemd/system/
然后在节点2和节点3分别修改etcd.conf配置文件中的节点名称和当前服务器IP:
vi /opt/etcd/cfg/etcd.conf #[Member] ETCD_NAME="etcd-1" # 修改此处,节点2改为etcd-2,节点3改为etcd-3 ETCD_DATA_DIR="/var/lib/etcd/default.etcd" ETCD_LISTEN_PEER_URLS="https://192.168.31.71:2380" # 修改此处为当前服务器IP ETCD_LISTEN_CLIENT_URLS="https://192.168.31.71:2379" # 修改此处为当前服务器IP #[Clustering] ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.31.71:2380" # 修改此处为当前服务器IP ETCD_ADVERTISE_CLIENT_URLS="https://192.168.31.71:2379" # 修改此处为当前服务器IP ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.31.71:2380,etcd-2=https://192.168.31.72:2380,etcd-3=https://192.168.31.73:2380" ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster" ETCD_INITIAL_CLUSTER_STATE="new"
最后启动etcd并设置开机启动,同上。
ETCDCTL_API=3 /opt/etcd/bin/etcdctl --cacert=/opt/etcd/ssl/ca.pem --cert=/opt/etcd/ssl/server.pem --key=/opt/etcd/ssl/server-key.pem --endpoints="https://192.168.16.80:2379,https://192.168.16.81:2379,https://192.168.16.82:2379" endpoint health --write-out=table
+----------------------------+--------+-------------+-------+
| ENDPOINT | HEALTH | TOOK | ERROR |
+----------------------------+--------+-------------+-------+
| https://192.168.31.61:2379 | true | 10.301506ms | |
| https://192.168.31.63:2379 | true | 12.87467ms | |
| https://192.168.31.62:2379 | true | 13.225954ms | |
+----------------------------+--------+-------------+-------+
查看原因tailf -n 10 /var/log/messages request sent was ignored by remote peer due to cluster ID mismatch
问题解决:
针对新集群的解决办法
停止三个etcd服务,将三个节点的etcd数据都删除,再重载启动,三个etcd服务都能正常启动了。
[root@k8s-master01 ~]# systemctl stop etcd
[root@k8s-master01 ~]# cd /var/lib/etcd/default.etcd
[root@k8s-master01 default.etcd]# rm -rf member/
[root@k8s-master01 default.etcd]# systemctl daemon-reload
[root@k8s-master01 default.etcd]# systemctl start etcd
分析:之前第三个etcd服务不能启动(状态一直是启动中)的原因是因为那个服务器的时间与其它两台不同步。
ntpdate cn.pool.ntp.org
除了安装ntpdate服务并执行同步时间服务器外,还需要将ntpdate服务设置成开机自启
如果输出上面信息,就说明集群部署成功。
如果有问题第一步先看日志:/var/log/message 或 journalctl -u etcd
四、安装Docker/kubeadm/kubelet【所有节点】
这里使用Docker作为容器引擎,也可以换成别的,例如containerd
4.1 安装Docker
wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo yum -y install docker-ce systemctl enable docker && systemctl start docker
配置镜像下载加速器:
cat > /etc/docker/daemon.json << EOF
{
"registry-mirrors": ["https://b9pmyelo.mirror.aliyuncs.com"]
}
EOF
systemctl restart docker
docker info
4.2 添加阿里云YUM软件源
cat > /etc/yum.repos.d/kubernetes.repo << EOF
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF
4.3 安装kubeadm,kubelet和kubectl
由于版本更新频繁,这里指定版本号部署:
yum install -y kubelet-1.20.0 kubeadm-1.20.0 kubectl-1.20.0
systemctl enable kubelet
五、部署Kubernetes Master
如果你在学习中遇到问题或者文档有误可联系阿良~ 微信: xyz12366699
5.1 初始化Master1
生成初始化配置文件:
cat > kubeadm-config.yaml << EOF apiVersion: kubeadm.k8s.io/v1beta2 bootstrapTokens: - groups: - system:bootstrappers:kubeadm:default-node-token token: 9037x2.tcaqnpaqkra9vsbw ttl: 24h0m0s usages: - signing - authentication kind: InitConfiguration localAPIEndpoint: advertiseAddress: 192.168.16.80 bindPort: 6443 nodeRegistration: criSocket: /var/run/dockershim.sock name: k8s-master01 taints: - effect: NoSchedule key: node-role.kubernetes.io/master --- apiServer: certSANs: # 包含所有Master/LB/VIP IP,一个都不能少!为了方便后期扩容可以多写几个预留的IP。 - k8s-master01 - k8s-master02 - 192.168.16.80 - 192.168.16.81 - 192.168.16.82 - 127.0.0.1 extraArgs: authorization-mode: Node,RBAC timeoutForControlPlane: 4m0s apiVersion: kubeadm.k8s.io/v1beta2 certificatesDir: /etc/kubernetes/pki clusterName: kubernetes controlPlaneEndpoint: 192.168.16.88:16443 # 负载均衡虚拟IP(VIP)和端口 controllerManager: {} dns: type: CoreDNS etcd: external: # 使用外部etcd endpoints: - https://192.168.16.80:2379 # etcd集群3个节点 - https://192.168.16.81:2379 - https://192.168.16.82:2379 caFile: /opt/etcd/ssl/ca.pem # 连接etcd所需证书 certFile: /opt/etcd/ssl/server.pem keyFile: /opt/etcd/ssl/server-key.pem imageRepository: registry.aliyuncs.com/google_containers # 由于默认拉取镜像地址k8s.gcr.io国内无法访问,这里指定阿里云镜像仓库地址 kind: ClusterConfiguration kubernetesVersion: v1.20.0 # K8s版本,与上面安装的一致 networking: dnsDomain: cluster.local podSubnet: 10.244.0.0/16 # Pod网络,与下面部署的CNI网络组件yaml中保持一致 serviceSubnet: 10.96.0.0/12 # 集群内部虚拟网络,Pod统一访问入口 scheduler: {} EOF
或者使用配置文件引导:
kubeadm init --config kubeadm-config.yaml ... Your Kubernetes control-plane has initialized successfully! To start using your cluster, you need to run the following as a regular user: mkdir -p $HOME/.kube sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config sudo chown $(id -u):$(id -g) $HOME/.kube/config Alternatively, if you are the root user, you can run: export KUBECONFIG=/etc/kubernetes/admin.conf You should now deploy a pod network to the cluster. Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at: https://kubernetes.io/docs/concepts/cluster-administration/addons/ 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 192.168.31.88:16443 --token 9037x2.tcaqnpaqkra9vsbw \ --discovery-token-ca-cert-hash sha256:b1e726042cdd5df3ce62e60a2f86168cd2e64bff856e061e465df10cd36295b8 \ --control-plane Then you can join any number of worker nodes by running the following on each as root: kubeadm join 192.168.31.88:16443 --token 9037x2.tcaqnpaqkra9vsbw \ --discovery-token-ca-cert-hash sha256:b1e726042cdd5df3ce62e60a2f86168cd2e64bff856e061e465df10cd36295b8
初始化完成后,会有两个join的命令,带有 --control-plane 是用于加入组建多master集群的,不带的是加入节点的。
拷贝kubectl使用的连接k8s认证文件到默认路径:
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master1 NotReady control-plane,master 6m42s v1.20.0
5.2 初始化Master2
将Master1节点生成的证书拷贝到Master2:
scp -r /etc/kubernetes/pki/ 192.168.16.81:/etc/kubernetes/
复制加入master join命令在master2执行:
kubeadm join 192.168.31.88:16443 --token 9037x2.tcaqnpaqkra9vsbw \
--discovery-token-ca-cert-hash sha256:b1e726042cdd5df3ce62e60a2f86168cd2e64bff856e061e465df10cd36295b8 \
--control-plane
拷贝kubectl使用的连接k8s认证文件到默认路径:
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master1 NotReady control-plane,master 28m v1.20.0
k8s-master2 NotReady control-plane,master 2m12s v1.20.0
注:由于网络插件还没有部署,还没有准备就绪 NotReady
5.3 访问负载均衡器测试
找K8s集群中任意一个节点,使用curl查看K8s版本测试,使用VIP访问:
curl -k https://192.168.16.88:16443/version
{
"major": "1",
"minor": "20",
"gitVersion": "v1.20.0",
"gitCommit": "e87da0bd6e03ec3fea7933c4b5263d151aafd07c",
"gitTreeState": "clean",
"buildDate": "2021-02-18T16:03:00Z",
"goVersion": "go1.15.8",
"compiler": "gc",
"platform": "linux/amd64"
}
可以正确获取到K8s版本信息,说明负载均衡器搭建正常。该请求数据流程:curl -> vip(nginx) -> apiserver
通过查看Nginx日志也可以看到转发apiserver IP:
tail /var/log/nginx/k8s-access.log -f
192.168.31.71 192.168.31.71:6443 - [02/Apr/2021:19:17:57 +0800] 200 423
192.168.31.71 192.168.31.72:6443 - [02/Apr/2021:19:18:50 +0800] 200 423
六、加入Kubernetes Node
在192.168.16.82(Node)执行。
向集群添加新节点,执行在kubeadm init输出的kubeadm join命令:
kubeadm join 192.168.16.88:16443 --token 9037x2.tcaqnpaqkra9vsbw \
--discovery-token-ca-cert-hash sha256:e6a724bb7ef8bb363762fbaa088f6eb5975e0c654db038560199a7063735a697
后续其他节点也是这样加入。
注:默认token有效期为24小时,当过期之后,该token就不可用了。这时就需要重新创建token,可以直接使用命令快捷生成:kubeadm token create --print-join-command
七、部署网络组件
Calico是一个纯三层的数据中心网络方案,是目前Kubernetes主流的网络方案。
部署Calico:
kubectl apply -f calico.yaml
kubectl get pods -n kube-system
等Calico Pod都Running,节点也会准备就绪:
kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master1 Ready control-plane,master 50m v1.20.0
k8s-master2 Ready control-plane,master 24m v1.20.0
k8s-node1 Ready <none> 20m v1.20.0
八、部署 Dashboard
Dashboard是官方提供的一个UI,可用于基本管理K8s资源。
kubectl apply -f kubernetes-dashboard.yaml # 查看部署 kubectl get pods -n kubernetes-dashboard
访问地址:https://NodeIP:30001
创建service account并绑定默认cluster-admin管理员集群角色:
kubectl create serviceaccount dashboard-admin -n kube-system
kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kube-system:dashboard-admin
kubectl describe secrets -n kube-system $(kubectl -n kube-system get secret | awk '/dashboard-admin/{print $1}')
使用输出的token登录Dashboard。