kubeadm安装 多master节点的k8s高可用集群
Swap是交换分区，如果机器内存不够，会使用swap分区，但是swap分区的性能较低，k8s设计的时候为了能提升性能，默认是不允许使用交换分区的。Kubeadm初始化的时候会检测swap是否关闭，如果没关闭，那就初始化失败。拉取镜像，但是k8s.gcr.io访问不到，所以需要指定从registry.aliyuncs.com/google_containers仓库拉取镜像。说明：：手动指定仓库地址为
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一、环境规划
1.1、实验环境规划
| K8S集群角色 | Ip | 主机名 | 安装的组件 |
|---|---|---|---|
| 控制节点 | 192.168.40.180 | k8s-master1 | apiserver、controller-manager、scheduler、etcd、docker、kubelet、kube-proxy、keepalived、nginx、calico |
| 控制节点 | 192.168.40.181 | k8s-master2 | apiserver、controller-manager、scheduler、etcd、docker、kubelet、kube-proxy、keepalived、nginx、calico |
| 工作节点 | 192.168.40.182 | k8s-node1 | kubelet、kube-proxy、docker、calico、coredns |
| Vip | 192.168.40.199 |
实验环境规划：
- 操作系统：centos7.6
- 配置： 4Gib内存/4vCPU/100G硬盘
- 网络：Vmware NAT模式
k8s网络环境规划：
-
k8s版本：
v1.20.6 -
Pod网段：
10.244.0.0/16 -
Service网段：
10.10.0.0/16
1.2、节点初始化
1）配置静态ip地址
# 把虚拟机或者物理机配置成静态ip地址，这样机器重新启动后ip地址也不会发生改变。以master1主机修改静态IP为例
~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0
TYPE=Ethernet
BOOTPROTO=none
NAME=eth0
DEVICE=eth0
ONBOOT=yes
IPADDR=192.168.40.180 # 按实验规划修改
NETMASK=255.255.255.0
GATEWAY=192.168.40.2
DNS1=223.5.5.5
# 重启网络
~]# systemctl restart network
# 测试网络连通信
~]# ping baidu.com
PING baidu.com (39.156.69.79) 56(84) bytes of data.
64 bytes from 39.156.69.79 (39.156.69.79): icmp_seq=1 ttl=128 time=63.2 ms
64 bytes from 39.156.69.79 (39.156.69.79): icmp_seq=2 ttl=128 time=47.3 ms
2）配置主机名
~]# hostnamectl set-hostname <主机名> && bash
3）配置hosts文件
# 所有机器
cat >> /etc/hosts << EOF
192.168.40.180 k8s-master1
192.168.40.181 k8s-master2
192.168.40.182 k8s-node1
EOF
# 测试
~]# ping k8s-master1
PING k8s-master1 (192.168.40.180) 56(84) bytes of data.
64 bytes from k8s-master1 (192.168.40.180): icmp_seq=1 ttl=64 time=0.015 ms
64 bytes from k8s-master1 (192.168.40.180): icmp_seq=2 ttl=64 time=0.047 ms
4）配置主机之间无密码登录
# 生成ssh 密钥对,一路回车，不输入密码
ssh-keygen -t rsa
# 把本地的ssh公钥文件安装到远程主机对应的账户
ssh-copy-id -i .ssh/id_rsa.pub k8s-master1
ssh-copy-id -i .ssh/id_rsa.pub k8s-master2
ssh-copy-id -i .ssh/id_rsa.pub k8s-node1
5）关闭firewalld防火墙
systemctl stop firewalld && systemctl disable firewalld
6）关闭selinux
# 临时关闭
setenforce 0
# 永久关闭
sed -i 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config
# 查看
getenforce
7）关闭交换分区swap
#临时关闭
swapoff -a
#永久关闭：注释swap挂载，给swap开头加一下注释
sed -ri 's/.*swap.*/#&/' /etc/fstab
#注意：如果是克隆的虚拟机，需要删除UUID一行
问题一：为什么要关闭swap交换分区？
Swap是交换分区，如果机器内存不够，会使用swap分区，但是swap分区的性能较低，k8s设计的时候为了能提升性能，默认是不允许使用交换分区的。Kubeadm初始化的时候会检测swap是否关闭，如果没关闭，那就初始化失败。如果不想要关闭交换分区，安装k8s的时候可以指定--ignore-preflight-errors=Swap来解决。
8）修改内核参数
# 1、加载br_netfilter模块
modprobe br_netfilter
# 2、验证模块是否加载成功
lsmod |grep br_netfilter
# 3、修改内核参数
cat > /etc/sysctl.d/k8s.conf <<EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
EOF
# 4、使刚才修改的内核参数生效
sysctl -p /etc/sysctl.d/k8s.conf
9）配置阿里云repo源
# 备份
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
# 下载新的CentOS-Base.repo
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
# 生成缓存
yum clean all && yum makecache
10）配置时间同步
# 安装ntpdate命令，
yum install ntpdate -y
# 跟网络源做同步
ntpdate cn.pool.ntp.org
# 把时间同步做成计划任务
crontab -e
* */1 * * * /usr/sbin/ntpdate cn.pool.ntp.org
# 重启crond服务
service crond restart
11）安装iptables
# 安装iptables
yum install iptables-services -y
# 禁用iptables
service iptables stop && systemctl disable iptables
# 清空防火墙规则
iptables -F
12）开启ipvs
不开启ipvs将会使用iptables进行数据包转发，但是效率低，所以官网推荐需要开通ipvs。
# 创建ipvs.modules文件
~]# vim /etc/sysconfig/modules/ipvs.modules
#!/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_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 [ 0 -eq 0 ]; then
/sbin/modprobe ${kernel_module}
fi
done
# 执行脚本
~]# chmod 755 /etc/sysconfig/modules/ipvs.modules && bash /etc/sysconfig/modules/ipvs.modules && lsmod | grep ip_vs
ip_vs_ftp 13079 0
nf_nat 26787 1 ip_vs_ftp
ip_vs_sed 12519 0
ip_vs_nq 12516 0
ip_vs_sh 12688 0
ip_vs_dh 12688 0
ip_vs_lblcr 12922 0
ip_vs_lblc 12819 0
ip_vs_wrr 12697 0
ip_vs_rr 12600 0
ip_vs_wlc 12519 0
ip_vs_lc 12516 0
ip_vs 141092 22 ip_vs_dh,ip_vs_lc,ip_vs_nq,ip_vs_rr,ip_vs_sh,ip_vs_ftp,ip_vs_sed,ip_vs_wlc,ip_vs_wrr,ip_vs_lblcr,ip_vs_lblc
nf_conntrack 133387 2 ip_vs,nf_nat
libcrc32c 12644 4 xfs,ip_vs,nf_nat,nf_conntrack
注意事项：
# ipvs是什么？
ipvs (IP Virtual Server) 实现了传输层负载均衡，也就是我们常说的4层LAN交换，作为 Linux 内核的一部分。ipvs运行在主机上，在真实服务器集群前充当负载均衡器。ipvs可以将基于TCP和UDP的服务请求转发到真实服务器上，并使真实服务器的服务在单个 IP 地址上显示为虚拟服务。
# ipvs和iptable对比分析
kube-proxy支持 iptables 和 ipvs 两种模式， 在kubernetes v1.8 中引入了 ipvs 模式，在 v1.9 中处于 beta 阶段，在 v1.11 中已经正式可用了。iptables 模式在 v1.1 中就添加支持了，从 v1.2 版本开始 iptables 就是 kube-proxy 默认的操作模式，ipvs 和 iptables 都是基于netfilter的，但是ipvs采用的是hash表，因此当service数量达到一定规模时，hash查表的速度优势就会显现出来，从而提高service的服务性能。那么 ipvs 模式和 iptables 模式之间有哪些差异呢？
1、ipvs 为大型集群提供了更好的可扩展性和性能
2、ipvs 支持比 iptables 更复杂的复制均衡算法（最小负载、最少连接、加权等等）
3、ipvs 支持服务器健康检查和连接重试等功能
13）安装基础软件包
~]# yum install -y yum-utils device-mapper-persistent-data lvm2 wget net-tools nfs-utils lrzsz gcc gcc-c++ make cmake libxml2-devel openssl-devel curl curl-devel unzip sudo ntp libaio-devel wget vim ncurses-devel autoconf automake zlib-devel python-devel epel-release openssh-server socat ipvsadm conntrack ntpdate telnet rsync
14）安装docker-ce
~]# yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
~]# yum install docker-ce docker-ce-cli containerd.io -y
~]# systemctl start docker && systemctl enable docker.service && systemctl status docker
15）配置docker镜像加速器
# 注意：修改docker文件驱动为systemd，默认为cgroupfs，kubelet默认使用systemd，两者必须一致才可以
~]# tee /etc/docker/daemon.json << 'EOF'
{
"registry-mirrors":["https://rsbud4vc.mirror.aliyuncs.com","https://registry.docker-cn.com","https://docker.mirrors.ustc.edu.cn","https://dockerhub.azk8s.cn","http://hub-mirror.c.163.com","http://qtid6917.mirror.aliyuncs.com", "https://rncxm540.mirror.aliyuncs.com"],
"exec-opts": ["native.cgroupdriver=systemd"]
}
EOF
~]# systemctl daemon-reload && systemctl restart docker && systemctl status docker
二、部署nginx及keepalived
1）安装nginx，keepalived
# 在k8s-master1和k8s-master2上做nginx主备安装
[root@k8s-master1 ~]# yum install nginx keepalived -y
[root@k8s-master2 ~]# yum install nginx keepalived -y
# 注意需要安装如下模块，报错：nginx: [emerg] unknown directive "stream" in /etc/nginx/nginx.conf:13
[root@k8s-master1 ~]# yum install nginx-mod-stream -y
[root@k8s-master1 ~]# nginx -v
nginx version: nginx/1.20.1
2）修改nginx配置文件，主备一样
[root@k8s-master1 ~]# cat /etc/nginx/nginx.conf
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 $upstream_bytes_sent';
access_log /var/log/nginx/k8s-access.log main;
upstream k8s-apiserver {
server 192.168.40.180:6443; # k8s-master1 APISERVER IP:PORT
server 192.168.40.181:6443; # k8s-master2 APISERVER IP:PORT
}
server {
listen 16443; # 由于nginx与master节点复用，这个监听端口不能是6443，否则会冲突
proxy_pass k8s-apiserver;
}
}
http {
log_format main '$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 / {
}
}
}
[root@k8s-master2 ~]# cat /etc/nginx/nginx.conf
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 $upstream_bytes_sent';
access_log /var/log/nginx/k8s-access.log main;
upstream k8s-apiserver {
server 192.168.40.180:6443; # k8s-master1 APISERVER IP:PORT
server 192.168.40.181:6443; # k8s-master2 APISERVER IP:PORT
}
server {
listen 16443; # 由于nginx与master节点复用，这个监听端口不能是6443，否则会冲突
proxy_pass k8s-apiserver;
}
}
http {
log_format main '$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 / {
}
}
}
3）keepalive配置
# master上配置
[root@k8s-master1 ~]# cat /etc/keepalived/keepalived.conf
global_defs {
notification_email {
acassen@firewall.loc
failover@firewall.loc
sysadmin@firewall.loc
}
notification_email_from Alexandre.Cassen@firewall.loc
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 eth0 # 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 {
192.168.40.199/24
}
track_script {
check_nginx
}
}
# master节点脚本配置
[root@k8s-master1 ~]# cat /etc/keepalived/check_nginx.sh
#!/bin/bash
count=$(ps -ef |grep nginx | grep sbin | egrep -cv "grep|$$")
if [ "$count" -eq 0 ];then
systemctl stop keepalived
fi
[root@k8s-master1 ~]# chmod +x /etc/keepalived/check_nginx.sh
# 备节点配置
[root@k8s-master2 ~]# cat /etc/keepalived/keepalived.conf
global_defs {
notification_email {
acassen@firewall.loc
failover@firewall.loc
sysadmin@firewall.loc
}
notification_email_from Alexandre.Cassen@firewall.loc
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id NGINX_BACKUP
}
vrrp_script check_nginx {
script "/etc/keepalived/check_nginx.sh"
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 51 # VRRP 路由 ID实例，每个实例是唯一的
priority 90
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.40.199/24
}
track_script {
check_nginx
}
}
[root@k8s-master2 ~]# cat /etc/keepalived/check_nginx.sh
#!/bin/bash
count=$(ps -ef |grep nginx | grep sbin | egrep -cv "grep|$$")
if [ "$count" -eq 0 ];then
systemctl stop keepalived
fi
[root@k8s-master2 ~]# 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。
4）启动服务
[root@k8s-master1 ~]# systemctl daemon-reload && systemctl start nginx keepalived && systemctl enable nginx keepalived
[root@k8s-master2 ~]# systemctl daemon-reload && systemctl start nginx keepalived && systemctl enable nginx keepalived
5）测试vip是否绑定成功
[root@k8s-master1 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:52:bf:68 brd ff:ff:ff:ff:ff:ff
inet 192.168.40.180/24 brd 192.168.40.255 scope global eth0
valid_lft forever preferred_lft forever
inet 192.168.40.199/24 scope global secondary eth0
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fe52:bf68/64 scope link
valid_lft forever preferred_lft forever
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN
link/ether 02:42:fc:92:c8:72 brd ff:ff:ff:ff:ff:ff
inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
valid_lft forever preferred_lft forever
[root@k8s-master2 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:f1:81:61 brd ff:ff:ff:ff:ff:ff
inet 192.168.40.181/24 brd 192.168.40.255 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fef1:8161/64 scope link
valid_lft forever preferred_lft forever
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN
link/ether 02:42:c6:90:ba:4c brd ff:ff:ff:ff:ff:ff
inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
valid_lft forever preferred_lft forever
6）测试keepalived
# 停掉k8s-master1上的nginx,vip会漂移到k8s-master2
[root@k8s-master1 ~]# systemctl stop nginx
[root@k8s-master1 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:52:bf:68 brd ff:ff:ff:ff:ff:ff
inet 192.168.40.180/24 brd 192.168.40.255 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fe52:bf68/64 scope link
valid_lft forever preferred_lft forever
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN
link/ether 02:42:fc:92:c8:72 brd ff:ff:ff:ff:ff:ff
inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
valid_lft forever preferred_lft forever
[root@k8s-master2 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:f1:81:61 brd ff:ff:ff:ff:ff:ff
inet 192.168.40.181/24 brd 192.168.40.255 scope global eth0
valid_lft forever preferred_lft forever
inet 192.168.40.199/24 scope global secondary eth0
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fef1:8161/64 scope link
valid_lft forever preferred_lft forever
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN
link/ether 02:42:c6:90:ba:4c brd ff:ff:ff:ff:ff:ff
inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
valid_lft forever preferred_lft forever
# 重新启动master1的nginx和keepalived，vip会漂移回来
[root@k8s-master1 ~]# systemctl start nginx
[root@k8s-master1 ~]# systemctl start keepalived
[root@k8s-master1 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:52:bf:68 brd ff:ff:ff:ff:ff:ff
inet 192.168.40.180/24 brd 192.168.40.255 scope global eth0
valid_lft forever preferred_lft forever
inet 192.168.40.199/24 scope global secondary eth0
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fe52:bf68/64 scope link
valid_lft forever preferred_lft forever
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN
link/ether 02:42:fc:92:c8:72 brd ff:ff:ff:ff:ff:ff
inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
valid_lft forever preferred_lft forever
7）查看端口状态
[root@k8s-master1 ~]# netstat -lntp|grep 16443
tcp 0 0 0.0.0.0:16443 0.0.0.0:* LISTEN 22461/nginx: master
[root@k8s-master2 ~]# netstat -lntp|grep 16443
tcp 0 0 0.0.0.0:16443 0.0.0.0:* LISTEN 22461/nginx: master
三、kubeadm部署集群
3.1、配置kubernetes的repo源
[root@k8s-master1 ~]# vim /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=0
# 将k8s-master1上Kubernetes的repo源复制给k8s-master2和k8s-node1
[root@k8s-master1 ~]# scp /etc/yum.repos.d/kubernetes.repo k8s-master2:/etc/yum.repos.d/
[root@k8s-master1 ~]# scp /etc/yum.repos.d/kubernetes.repo k8s-node1:/etc/yum.repos.d/
3.2、下载相关软件包
# 注意：可以看到kubelet状态不是running状态，这个是正常的，不用管，等k8s组件起来这个kubelet就正常了
[root@k8s-master1 ~]# yum install -y kubelet-1.20.6 kubeadm-1.20.6 kubectl-1.20.6
[root@k8s-master1 ~]# systemctl enable kubelet && systemctl start kubelet
[root@k8s-master1 ~]# systemctl status kubelet
[root@k8s-master2 ~]# yum install -y kubelet-1.20.6 kubeadm-1.20.6 kubectl-1.20.6
[root@k8s-master2 ~]# systemctl enable kubelet && systemctl start kubelet
[root@k8s-master2 ~]# systemctl status kubelet
[root@k8s-node1 ~]# yum install -y kubelet-1.20.6 kubeadm-1.20.6 kubectl-1.20.6
[root@k8s-node1 ~]# systemctl enable kubelet && systemctl start kubelet
[root@k8s-node1 ~]# systemctl status kubelet
3.3、kubeadm初始化k8s集群
1）创建kubeadm-config.yaml文件
[root@k8s-master1 ~]# vim kubeadm-config.yaml
apiVersion: kubeadm.k8s.io/v1beta2
kind: ClusterConfiguration
kubernetesVersion: v1.20.6
controlPlaneEndpoint: 192.168.40.199:16443
imageRepository: registry.aliyuncs.com/google_containers
apiServer:
certSANs:
- 192.168.40.180
- 192.168.40.181
- 192.168.40.182
- 192.168.40.199
networking:
podSubnet: 10.244.0.0/16
serviceSubnet: 10.10.0.0/16
---
apiVersion: kubeproxy.config.k8s.io/v1alpha1
kind: KubeProxyConfiguration
mode: ipvs
参数--image-repository registry.aliyuncs.com/google_containers说明：：手动指定仓库地址为registry.aliyuncs.com/google_containers，kubeadm默认从k8s.grc.io拉取镜像，但是k8s.gcr.io访问不到，所以需要指定从registry.aliyuncs.com/google_containers仓库拉取镜像
2）使用kubeadm初始化k8s集群
[root@k8s-master1 ~]# kubeadm init --config kubeadm-config.yaml
[init] Using Kubernetes version: v1.20.6
[preflight] Running pre-flight checks
[WARNING SystemVerification]: this Docker version is not on the list of validated versions: 20.10.7. Latest validated version: 19.03
[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two, depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'
[certs] Using certificateDir folder "/etc/kubernetes/pki"
[certs] Generating "ca" certificate and key
[certs] Generating "apiserver" certificate and key
[certs] apiserver serving cert is signed for DNS names [k8s-master1 kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.10.0.1 192.168.40.180 192.168.40.199 192.168.40.181 192.168.40.182]
[certs] Generating "apiserver-kubelet-client" certificate and key
[certs] Generating "front-proxy-ca" certificate and key
[certs] Generating "front-proxy-client" certificate and key
[certs] Generating "etcd/ca" certificate and key
[certs] Generating "etcd/server" certificate and key
[certs] etcd/server serving cert is signed for DNS names [k8s-master1 localhost] and IPs [192.168.40.180 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [k8s-master1 localhost] and IPs [192.168.40.180 127.0.0.1 ::1]
[certs] Generating "etcd/healthcheck-client" certificate and key
[certs] Generating "apiserver-etcd-client" certificate and key
[certs] Generating "sa" key and public key
[kubeconfig] Using kubeconfig folder "/etc/kubernetes"
[endpoint] WARNING: port specified in controlPlaneEndpoint overrides bindPort in the controlplane address
[kubeconfig] Writing "admin.conf" kubeconfig file
[endpoint] WARNING: port specified in controlPlaneEndpoint overrides bindPort in the controlplane address
[kubeconfig] Writing "kubelet.conf" kubeconfig file
[endpoint] WARNING: port specified in controlPlaneEndpoint overrides bindPort in the controlplane address
[kubeconfig] Writing "controller-manager.conf" kubeconfig file
[endpoint] WARNING: port specified in controlPlaneEndpoint overrides bindPort in the controlplane address
[kubeconfig] Writing "scheduler.conf" kubeconfig file
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Starting the kubelet
[control-plane] Using manifest folder "/etc/kubernetes/manifests"
[control-plane] Creating static Pod manifest for "kube-apiserver"
[control-plane] Creating static Pod manifest for "kube-controller-manager"
[control-plane] Creating static Pod manifest for "kube-scheduler"
[etcd] Creating static Pod manifest for local etcd in "/etc/kubernetes/manifests"
[wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory "/etc/kubernetes/manifests". This can take up to 4m0s
[kubelet-check] Initial timeout of 40s passed.
[apiclient] All control plane components are healthy after 113.537013 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.20" in namespace kube-system with the configuration for the kubelets in the cluster
[upload-certs] Skipping phase. Please see --upload-certs
[mark-control-plane] Marking the node k8s-master1 as control-plane by adding the labels "node-role.kubernetes.io/master=''" and "node-role.kubernetes.io/control-plane='' (deprecated)"
[mark-control-plane] Marking the node k8s-master1 as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: d8j1ts.o62xh6zi98031f5l
[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to get nodes
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstrap-token] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstrap-token] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstrap-token] Creating the "cluster-info" ConfigMap in the "kube-public" namespace
[kubelet-finalize] Updating "/etc/kubernetes/kubelet.conf" to point to a rotatable kubelet client certificate and key
[addons] Applied essential addon: CoreDNS
[endpoint] WARNING: port specified in controlPlaneEndpoint overrides bindPort in the controlplane address
[addons] Applied essential addon: kube-proxy
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 192.168.40.199:16443 --token d8j1ts.o62xh6zi98031f5l \
--discovery-token-ca-cert-hash sha256:1fa4f67a0e1ee0c3277f10929df562b0fa621cc44ffb16ff8fadb52c667f0a1b \
--control-plane
Then you can join any number of worker nodes by running the following on each as root:
kubeadm join 192.168.40.199:16443 --token d8j1ts.o62xh6zi98031f5l \
--discovery-token-ca-cert-hash sha256:1fa4f67a0e1ee0c3277f10929df562b0fa621cc44ffb16ff8fadb52c667f0a1b
3）配置kubectl的配置文件config
[root@k8s-master1 ~]# mkdir -p $HOME/.kube
[root@k8s-master1 ~]# sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
[root@k8s-master1 ~]# sudo chown $(id -u):$(id -g) $HOME/.kube/config
[root@k8s-master1 ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-master1 NotReady control-plane,master 2m27s v1.20.6
# 此时集群状态还是NotReady状态，因为没有安装网络插件。
3.4、扩容集群-添加master节点
1）创建证书存放目录
[root@k8s-master2 ~]# cd /root && mkdir -p /etc/kubernetes/pki/etcd && mkdir -p ~/.kube/
2）拷贝证书
[root@k8s-master1 ~]# scp /etc/kubernetes/pki/ca.crt k8s-master2:/etc/kubernetes/pki/
[root@k8s-master1 ~]# scp /etc/kubernetes/pki/ca.key k8s-master2:/etc/kubernetes/pki/
[root@k8s-master1 ~]# scp /etc/kubernetes/pki/sa.key k8s-master2:/etc/kubernetes/pki/
[root@k8s-master1 ~]# scp /etc/kubernetes/pki/sa.pub k8s-master2:/etc/kubernetes/pki/
[root@k8s-master1 ~]# scp /etc/kubernetes/pki/front-proxy-ca.crt k8s-master2:/etc/kubernetes/pki/
[root@k8s-master1 ~]# scp /etc/kubernetes/pki/front-proxy-ca.key k8s-master2:/etc/kubernetes/pki/
[root@k8s-master1 ~]# scp /etc/kubernetes/pki/etcd/ca.crt k8s-master2:/etc/kubernetes/pki/etcd/
[root@k8s-master1 ~]# scp /etc/kubernetes/pki/etcd/ca.key k8s-master2:/etc/kubernetes/pki/etcd/
[root@k8s-master1 ~]# scp /etc/kubernetes/pki/ca.crt k8s-master3:/etc/kubernetes/pki/
[root@k8s-master1 ~]# scp /etc/kubernetes/pki/ca.key k8s-master3:/etc/kubernetes/pki/
[root@k8s-master1 ~]# scp /etc/kubernetes/pki/sa.key k8s-master3:/etc/kubernetes/pki/
[root@k8s-master1 ~]# scp /etc/kubernetes/pki/sa.pub k8s-master3:/etc/kubernetes/pki/
[root@k8s-master1 ~]# scp /etc/kubernetes/pki/front-proxy-ca.crt k8s-master3:/etc/kubernetes/pki/
[root@k8s-master1 ~]# scp /etc/kubernetes/pki/front-proxy-ca.key k8s-master3:/etc/kubernetes/pki/
[root@k8s-master1 ~]# scp /etc/kubernetes/pki/etcd/ca.crt k8s-master3:/etc/kubernetes/pki/etcd/
[root@k8s-master1 ~]# scp /etc/kubernetes/pki/etcd/ca.key k8s-master3:/etc/kubernetes/pki/etcd/
3）新控制节点加入集群
# 查看token，注意控制节点加入集群需要加上--control-plane
[root@k8s-master1 ~]# kubeadm token create --print-join-command
kubeadm join 192.168.40.199:16443 --token qh0gw4.2brd8ioh2hyscd1a --discovery-token-ca-cert-hash sha256:1fa4f67a0e1ee0c3277f10929df562b0fa621cc44ffb16ff8fadb52c667f0a1b
# 新节点加入
[root@k8s-master2 ~]# kubeadm join 192.168.40.199:16443 --token qh0gw4.2brd8ioh2hyscd1a --discovery-token-ca-cert-hash sha256:1fa4f67a0e1ee0c3277f10929df562b0fa621cc44ffb16ff8fadb52c667f0a1b --control-plane
[preflight] Running pre-flight checks
[WARNING SystemVerification]: this Docker version is not on the list of validated versions: 20.10.7. Latest validated version: 19.03
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -o yaml'
[preflight] Running pre-flight checks before initializing the new control plane instance
[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two, depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'
[certs] Using certificateDir folder "/etc/kubernetes/pki"
[certs] Generating "apiserver" certificate and key
[certs] apiserver serving cert is signed for DNS names [k8s-master2 kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.10.0.1 192.168.40.181 192.168.40.199 192.168.40.180 192.168.40.182]
[certs] Generating "apiserver-kubelet-client" certificate and key
[certs] Generating "front-proxy-client" certificate and key
[certs] Generating "etcd/server" certificate and key
[certs] etcd/server serving cert is signed for DNS names [k8s-master2 localhost] and IPs [192.168.40.181 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [k8s-master2 localhost] and IPs [192.168.40.181 127.0.0.1 ::1]
[certs] Generating "etcd/healthcheck-client" certificate and key
[certs] Generating "apiserver-etcd-client" certificate and key
[certs] Valid certificates and keys now exist in "/etc/kubernetes/pki"
[certs] Using the existing "sa" key
[kubeconfig] Generating kubeconfig files
[kubeconfig] Using kubeconfig folder "/etc/kubernetes"
[endpoint] WARNING: port specified in controlPlaneEndpoint overrides bindPort in the controlplane address
[kubeconfig] Writing "admin.conf" kubeconfig file
[endpoint] WARNING: port specified in controlPlaneEndpoint overrides bindPort in the controlplane address
[kubeconfig] Writing "controller-manager.conf" kubeconfig file
[endpoint] WARNING: port specified in controlPlaneEndpoint overrides bindPort in the controlplane address
[kubeconfig] Writing "scheduler.conf" kubeconfig file
[control-plane] Using manifest folder "/etc/kubernetes/manifests"
[control-plane] Creating static Pod manifest for "kube-apiserver"
[control-plane] Creating static Pod manifest for "kube-controller-manager"
[control-plane] Creating static Pod manifest for "kube-scheduler"
[check-etcd] Checking that the etcd cluster is healthy
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Starting the kubelet
[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap...
[etcd] Announced new etcd member joining to the existing etcd cluster
[etcd] Creating static Pod manifest for "etcd"
[etcd] Waiting for the new etcd member to join the cluster. This can take up to 40s
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[mark-control-plane] Marking the node k8s-master2 as control-plane by adding the labels "node-role.kubernetes.io/master=''" and "node-role.kubernetes.io/control-plane='' (deprecated)"
[mark-control-plane] Marking the node k8s-master2 as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
This node has joined the cluster and a new control plane instance was created:
* Certificate signing request was sent to apiserver and approval was received.
* The Kubelet was informed of the new secure connection details.
* Control plane (master) label and taint were applied to the new node.
* The Kubernetes control plane instances scaled up.
* A new etcd member was added to the local/stacked etcd cluster.
To start administering your cluster from this node, 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
Run 'kubectl get nodes' to see this node join the cluster.
4）创建kubeconfig
[root@k8s-master2 ~]# mkdir -p $HOME/.kube
[root@k8s-master2 ~]# sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
[root@k8s-master2 ~]# sudo chown $(id -u):$(id -g) $HOME/.kube/config
5）查看集群状态
[root@k8s-master1 ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-master1 NotReady control-plane,master 24m v1.20.6
k8s-master2 NotReady control-plane,master 3m41s v1.20.6
3.5、扩容集群-添加node节点
1）加入集群
# 查看加入集群命令
[root@k8s-master1 ~]# kubeadm token create --print-join-command
kubeadm join 192.168.40.199:16443 --token ay4uyg.1x09kgx6ihjii29c --discovery-token-ca-cert-hash sha256:1fa4f67a0e1ee0c3277f10929df562b0fa621cc44ffb16ff8fadb52c667f0a1b
# 新node节点加入集群
[root@k8s-node1 ~]# kubeadm join 192.168.40.199:16443 --token ay4uyg.1x09kgx6ihjii29c --discovery-token-ca-cert-hash sha256:1fa4f67a0e1ee0c3277f10929df562b0fa621cc44ffb16ff8fadb52c667f0a1b
[preflight] Running pre-flight checks
[WARNING SystemVerification]: this Docker version is not on the list of validated versions: 20.10.7. Latest validated version: 19.03
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -o yaml'
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Starting the kubelet
[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap...
This node has joined the cluster:
* Certificate signing request was sent to apiserver and a response was received.
* The Kubelet was informed of the new secure connection details.
Run 'kubectl get nodes' on the control-plane to see this node join the cluster.
2）查看状态并打标签
[root@k8s-master1 ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-master1 NotReady control-plane,master 36m v1.20.6
k8s-master2 NotReady control-plane,master 16m v1.20.6
k8s-node1 NotReady <none> 93s v1.20.6
[root@k8s-master1 ~]# kubectl label node k8s-node1 node-role.kubernetes.io/worker=worker
node/k8s-node1 labeled
[root@k8s-master1 ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-master1 NotReady control-plane,master 36m v1.20.6
k8s-master2 NotReady control-plane,master 16m v1.20.6
k8s-node1 NotReady worker 107s v1.20.6
# 上面状态都是NotReady状态，说明没有安装网络插件
3）查看pod状态
[root@k8s-master1 ~]# kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
coredns-7f89b7bc75-5d8vn 0/1 Pending 0 37m # 网络插件未安装好
coredns-7f89b7bc75-xvkth 0/1 Pending 0 37m
etcd-k8s-master1 1/1 Running 0 37m
etcd-k8s-master2 1/1 Running 0 17m
kube-apiserver-k8s-master1 1/1 Running 1 37m
kube-apiserver-k8s-master2 1/1 Running 0 17m
kube-controller-manager-k8s-master1 1/1 Running 1 37m
kube-controller-manager-k8s-master2 1/1 Running 0 17m
kube-proxy-4r7kf 1/1 Running 0 37m
kube-proxy-6mwh6 1/1 Running 0 17m
kube-proxy-qsbp5 1/1 Running 0 2m44s
kube-scheduler-k8s-master1 1/1 Running 1 37m
kube-scheduler-k8s-master2 1/1 Running 0 17m
3.6、安装Calico
下载地址：https://docs.projectcalico.org/manifests/calico.yaml
[root@k8s-master1 ~]# kubectl apply -f calico.yaml
[root@k8s-master1 ~]# kubectl get pod -n kube-system
NAME READY STATUS RESTARTS AGE
calico-kube-controllers-6949477b58-lb52j 1/1 Running 0 3m58s
calico-node-9rqdd 1/1 Running 0 3m58s
calico-node-xdr5t 1/1 Running 0 3m58s
calico-node-xvkv5 1/1 Running 0 3m58s
coredns-7f89b7bc75-5d8vn 1/1 Running 0 49m
coredns-7f89b7bc75-xvkth 1/1 Running 0 49m
etcd-k8s-master1 1/1 Running 0 49m
etcd-k8s-master2 1/1 Running 0 29m
kube-apiserver-k8s-master1 1/1 Running 1 49m
kube-apiserver-k8s-master2 1/1 Running 0 29m
kube-controller-manager-k8s-master1 1/1 Running 1 49m
kube-controller-manager-k8s-master2 1/1 Running 0 29m
kube-proxy-4r7kf 1/1 Running 0 49m
kube-proxy-6mwh6 1/1 Running 0 29m
kube-proxy-qsbp5 1/1 Running 0 14m
kube-scheduler-k8s-master1 1/1 Running 1 49m
kube-scheduler-k8s-master2 1/1 Running 0 29m
[root@k8s-master1 ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-master1 Ready control-plane,master 50m v1.20.6
k8s-master2 Ready control-plane,master 29m v1.20.6
k8s-node1 Ready worker 15m v1.20.6
测试网络连通性：
[root@k8s-master1 ~]# kubectl get pod -n kube-system -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
calico-kube-controllers-6949477b58-lb52j 1/1 Running 0 5m49s 10.244.36.65 k8s-node1 <none> <none>
calico-node-9rqdd 1/1 Running 0 5m49s 192.168.40.182 k8s-node1 <none> <none>
calico-node-xdr5t 1/1 Running 0 5m49s 192.168.40.180 k8s-master1 <none> <none>
calico-node-xvkv5 1/1 Running 0 5m49s 192.168.40.181 k8s-master2 <none> <none>
coredns-7f89b7bc75-5d8vn 1/1 Running 0 51m 10.244.36.67 k8s-node1 <none> <none>
coredns-7f89b7bc75-xvkth 1/1 Running 0 51m 10.244.36.66 k8s-node1 <none> <none>
etcd-k8s-master1 1/1 Running 0 51m 192.168.40.180 k8s-master1 <none> <none>
etcd-k8s-master2 1/1 Running 0 30m 192.168.40.181 k8s-master2 <none> <none>
kube-apiserver-k8s-master1 1/1 Running 1 51m 192.168.40.180 k8s-master1 <none> <none>
kube-apiserver-k8s-master2 1/1 Running 0 30m 192.168.40.181 k8s-master2 <none> <none>
kube-controller-manager-k8s-master1 1/1 Running 1 51m 192.168.40.180 k8s-master1 <none> <none>
kube-controller-manager-k8s-master2 1/1 Running 0 31m 192.168.40.181 k8s-master2 <none> <none>
kube-proxy-4r7kf 1/1 Running 0 51m 192.168.40.180 k8s-master1 <none> <none>
kube-proxy-6mwh6 1/1 Running 0 31m 192.168.40.181 k8s-master2 <none> <none>
kube-proxy-qsbp5 1/1 Running 0 16m 192.168.40.182 k8s-node1 <none> <none>
kube-scheduler-k8s-master1 1/1 Running 1 51m 192.168.40.180 k8s-master1 <none> <none>
kube-scheduler-k8s-master2 1/1 Running 0 31m 192.168.40.181 k8s-master2 <none> <none>
# 注意使用busybox:1.28版本
[root@k8s-master1 ~]# kubectl run busybox --image busybox:1.28 --restart=Never --rm -it busybox -- sh
If you don't see a command prompt, try pressing enter.
/ # ping 10.244.36.67
PING 10.244.36.67 (10.244.36.67): 56 data bytes
64 bytes from 10.244.36.67: seq=0 ttl=63 time=0.113 ms
64 bytes from 10.244.36.67: seq=1 ttl=63 time=0.203 ms
/ # ping baidu.com
PING baidu.com (39.156.69.79): 56 data bytes
64 bytes from 39.156.69.79: seq=0 ttl=127 time=47.840 ms
64 bytes from 39.156.69.79: seq=1 ttl=127 time=62.833 ms
3.7、测试部署tomcat服务
[root@k8s-master1 ~]# cat tomcat.yaml
apiVersion: v1
kind: Pod
metadata:
name: demo-pod
namespace: default
labels:
app: myapp
env: dev
spec:
containers:
- name: tomcat-pod-java
ports:
- containerPort: 8080
image: tomcat:8.5-jre8-alpine
imagePullPolicy: IfNotPresent
- name: busybox
image: busybox:latest
command:
- "/bin/sh"
- "-c"
- "sleep 3600"
[root@k8s-master1 ~]# cat tomcat-service.yaml
apiVersion: v1
kind: Service
metadata:
name: tomcat
spec:
type: NodePort
ports:
- port: 8080
nodePort: 30080
selector:
app: myapp
env: dev
[root@k8s-master1 ~]# kubectl apply -f tomcat.yaml
pod/demo-pod created
[root@k8s-master1 ~]# kubectl apply -f tomcat-service.yaml
service/tomcat created
[root@k8s-master1 ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
demo-pod 2/2 Running 0 116s
[root@k8s-master1 ~]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.10.0.1 <none> 443/TCP 59m
tomcat NodePort 10.10.235.180 <none> 8080:30080/TCP 114s
浏览器访问测试：
3.8、测试coredns服务
# 注意：busybox要用指定的1.28版本，不能用最新版本，最新版本，nslookup会解析不到dns和ip
[root@k8s-master1 ~]# kubectl run busybox --image busybox:1.28 --restart=Never --rm -it busybox -- sh
If you don't see a command prompt, try pressing enter.
/ # nslookup kubernetes.default.svc.cluster.local
Server: 10.10.0.10
Address 1: 10.10.0.10 kube-dns.kube-system.svc.cluster.local
Name: kubernetes.default.svc.cluster.local
Address 1: 10.10.0.1 kubernetes.default.svc.cluster.local
/ # nslookup tomcat.default.svc.cluster.local
Server: 10.10.0.10
Address 1: 10.10.0.10 kube-dns.kube-system.svc.cluster.local
Name: tomcat.default.svc.cluster.local
Address 1: 10.10.235.180 tomcat.default.svc.cluster.local
五、实验总结
1、集群中只要有一个master节点正常运行就可以正常对外提供业务服务。
2、如果需要在master节点使用kubectl相关的命令，必须保证至少有2个master节点正常运行才可以使用，不然会有 Unable to connect to the server: net/http: TLS handshake timeout 这样的错误。
3、当一台可以查看nodes节点的master宕机之后，其余两台随机一台获取vip，然后可以观察nodes节点，但是当超过两台master宕机之后，集群需重建才可以观察nodes节点，但服务未停止；当两台宕机主机回复之后，服务停止，node节点不可观察，集群停止，需重建！
4、Node节点故障时pod自动转移：当pod所在的Node节点宕机后，根据 controller-manager的–pod-eviction-timeout 配置，默认是5分钟，5分钟后k8s会把pod状态设置为unkown， 然后在其它节点启动pod。当故障节点恢复后，k8s会删除故障节点上面的unkown pod。如果你想立即强制迁移，可以用 kubectl drain nodename
5、为了保证集群的高可用性，建议master节点和node节点至少分别部署3台及以上，且master节点应该部署基数个实例(3、5、7、9)。
多master kubespere 安装
apiVersion: installer.kubesphere.io/v1alpha1
kind: ClusterConfiguration
metadata:
name: ks-installer
namespace: kubesphere-system
labels:
version: v3.3.0
spec:
persistence:
storageClass: "" #这里保持默认即可，因为我们有了默认的存储类
authentication:
jwtSecret: "" # Keep the jwtSecret consistent with the Host Cluster. Retrieve the jwtSecret by executing "kubectl -n kubesphere-system get cm kubesphere-config -o yaml | grep -v "apiVersion" | grep jwtSecret" on the Host Cluster.
local_registry: "" # Add your private registry address if it is needed.
etcd:
monitoring: true # 改为"true"，表示开启etcd的监控功能
endpointIps: '17.2.1.220,17.2.1.221,17.2.1.222' # 改为自己的master节点IP地址
port: 2379 # etcd port.
tlsEnable: true
common:
redis:
enabled: true #改为"true"，开启redis功能
openldap:
enabled: true #改为"true"，开启轻量级目录协议
minioVolumeSize: 20Gi # Minio PVC size.
openldapVolumeSize: 2Gi # openldap PVC size.
redisVolumSize: 2Gi # Redis PVC size.
monitoring:
# type: external # Whether to specify the external prometheus stack, and need to modify the endpoint at the next line.
endpoint: http://prometheus-operated.kubesphere-monitoring-system.svc:9090 # Prometheus endpoint to get metrics data.
es: # Storage backend for logging, events and auditing.
# elasticsearchMasterReplicas: 1 # The total number of master nodes. Even numbers are not allowed.
# elasticsearchDataReplicas: 1 # The total number of data nodes.
elasticsearchMasterVolumeSize: 4Gi # The volume size of Elasticsearch master nodes.
elasticsearchDataVolumeSize: 20Gi # The volume size of Elasticsearch data nodes.
logMaxAge: 7 # Log retention time in built-in Elasticsearch. It is 7 days by default.
elkPrefix: logstash # The string making up index names. The index name will be formatted as ks-<elk_prefix>-log.
basicAuth:
enabled: false
username: ""
password: ""
externalElasticsearchUrl: ""
externalElasticsearchPort: ""
console:
enableMultiLogin: true # Enable or disable simultaneous logins. It allows different users to log in with the same account at the same time.
port: 30880
alerting: # (CPU: 0.1 Core, Memory: 100 MiB) It enables users to customize alerting policies to send messages to receivers in time with different time intervals and alerting levels to choose from.
enabled: true # 改为"true"，开启告警功能
# thanosruler:
# replicas: 1
# resources: {}
auditing: # Provide a security-relevant chronological set of records，recording the sequence of activities happening on the platform, initiated by different tenants.
enabled: true # 改为"true"，开启审计功能
devops: # (CPU: 0.47 Core, Memory: 8.6 G) Provide an out-of-the-box CI/CD system based on Jenkins, and automated workflow tools including Source-to-Image & Binary-to-Image.
enabled: true # 改为"true"，开启DevOps功能
jenkinsMemoryLim: 2Gi # Jenkins memory limit.
jenkinsMemoryReq: 1500Mi # Jenkins memory request.
jenkinsVolumeSize: 8Gi # Jenkins volume size.
jenkinsJavaOpts_Xms: 512m # The following three fields are JVM parameters.
jenkinsJavaOpts_Xmx: 512m
jenkinsJavaOpts_MaxRAM: 2g
events: # Provide a graphical web console for Kubernetes Events exporting, filtering and alerting in multi-tenant Kubernetes clusters.
enabled: true # 改为"true"，开启集群的事件功能
ruler:
enabled: true
replicas: 2
logging: # (CPU: 57 m, Memory: 2.76 G) Flexible logging functions are provided for log query, collection and management in a unified console. Additional log collectors can be added, such as Elasticsearch, Kafka and Fluentd.
enabled: true # 改为"true"，开启日志功能
logsidecar:
enabled: true
replicas: 2
metrics_server: # (CPU: 56 m, Memory: 44.35 MiB) It enables HPA (Horizontal Pod Autoscaler).
enabled: false # 这个不用修改，因为在上面我们已经安装过了，如果这里开启，镜像是官方的，会拉取镜像失败
monitoring:
storageClass: "" # If there is an independent StorageClass you need for Prometheus, you can specify it here. The default StorageClass is used by default.
# prometheusReplicas: 1 # Prometheus replicas are responsible for monitoring different segments of data source and providing high availability.
prometheusMemoryRequest: 400Mi # Prometheus request memory.
prometheusVolumeSize: 20Gi # Prometheus PVC size.
# alertmanagerReplicas: 1 # AlertManager Replicas.
multicluster:
clusterRole: none # host | member | none # You can install a solo cluster, or specify it as the Host or Member Cluster.
network:
networkpolicy: # Network policies allow network isolation within the same cluster, which means firewalls can be set up between certain instances (Pods).
# Make sure that the CNI network plugin used by the cluster supports NetworkPolicy. There are a number of CNI network plugins that support NetworkPolicy, including Calico, Cilium, Kube-router, Romana and Weave Net.
enabled: true # 改为"true"，开启网络策略
ippool: # Use Pod IP Pools to manage the Pod network address space. Pods to be created can be assigned IP addresses from a Pod IP Pool.
type: none #如果你的网络插件是calico，需要修改为"calico"，这里我是Flannel，保持默认。
topology: # Use Service Topology to view Service-to-Service communication based on Weave Scope.
type: none # Specify "weave-scope" for this field to enable Service Topology. "none" means that Service Topology is disabled.
openpitrix: # An App Store that is accessible to all platform tenants. You can use it to manage apps across their entire lifecycle.
store:
enabled: true # 改为"true"，开启应用商店
servicemesh: # (0.3 Core, 300 MiB) Provide fine-grained traffic management, observability and tracing, and visualized traffic topology.
enabled: true # 改为"true"，开启微服务治理
kubeedge: # Add edge nodes to your cluster and deploy workloads on edge nodes.
enabled: false # 这个就不修改了，这个是边缘服务，我们也没有边缘的设备。
cloudCore:
nodeSelector: {"node-role.kubernetes.io/worker": ""}
tolerations: []
cloudhubPort: "10000"
cloudhubQuicPort: "10001"
cloudhubHttpsPort: "10002"
cloudstreamPort: "10003"
tunnelPort: "10004"
cloudHub:
advertiseAddress: # At least a public IP address or an IP address which can be accessed by edge nodes must be provided.
- "" # Note that once KubeEdge is enabled, CloudCore will malfunction if the address is not provided.
nodeLimit: "100"
service:
cloudhubNodePort: "30000"
cloudhubQuicNodePort: "30001"
cloudhubHttpsNodePort: "30002"
cloudstreamNodePort: "30003"
tunnelNodePort: "30004"
edgeWatcher:
nodeSelector: {"node-role.kubernetes.io/worker": ""}
tolerations: []
edgeWatcherAgent:
nodeSelector: {"node-role.kubernetes.io/worker": ""}
tolerations: []
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