Centos7系统二进制安装Kubernetes(v1.18)集群

一、环境准备

1.1、集群环境

集群环境
角色 IP 组件
k8s-master01 192.168.100.31 kube-apiserver,kube-controller-manager,kube-scheduler,kubelet,kube-proxy,docker,etcd
k8s-master02 192.168.100.32

kube-apiserver,kube-controller-manager,kube-scheduler,kubelet,kube-proxy,docker

k8s-node01 192.168.100.33 kubelet,kube-proxy,docker,etcd
k8s-node01 192.168.100.34 kubelet、kube-proxy、docker、 etcd
nginx-master 192.168.100.35

kubelet,kube-proxy,docker,etcd

nginx-backup 192.168.100.36 Nginx L4+keepalived
VIP 192.168.100.37 Nginx L4+keepalived

1.2、软件环境

软件环境
软件 版本
操作系统

CentOS Linux release 7.9.2009 (Core)  内核:3.10.0-1160.99.1.el7.x86_64

Docker 19-ce
kubernetes 1.18

部署说明:

搭建这套K8s 高可用集群分两部分实施,先部署一套单 Master 架构(3 台),再扩容为多Master 架构(4 台或 6 台),顺便再熟悉下 Master 扩容流程。

单 Master 架构图:

 

1.3、系统环境初始化

1.3.1、修改网卡UUID

#查看网卡UUID
nmcli con

#获取新的UUID
uuidgen ens33

#把uuid添加到网卡配置
sed -i '5i UUID="aff7fd51-bc25-4724-93a7-c5fb44b98771"' /etc/sysconfig/network-scripts/ifcfg-ens33

#如果网卡里面有UUID的配置可以选择替换掉
sed -i 's/UUID="25ca232d-c891-4dd4-9566-55d0cf03c8b6"/UUID="aff7fd51-bc25-4724-93a7-c5fb44b98771"/g' /etc/sysconfig/network-scripts/ifcfg-ens33

#重启网卡
systemctl restart network

#查看
nmcli con

1.3.2、关闭防火墙

systemctl stop firewalld

systemctl disable --now firewalld

 1.3.3、关闭selinux

#永久关闭
sed -i 's/enforcing/disabled/' /etc/selinux/config

#临时关闭
setenforce 0 

1.3.4、关闭swap分区

sed -ri 's/.*swap.*/#&/' /etc/fstab

swapoff -a && sysctl -w vm.swappiness=0

cat /etc/fstab

# 参数解释:
# 
# -ri: 这个参数用于在原文件中替换匹配的模式。-r表示扩展正则表达式,-i允许直接修改文件。
# 's/.*swap.*/#&/': 这是一个sed命令,用于在文件/etc/fstab中找到包含swap的行,并在行首添加#来注释掉该行。
# /etc/fstab: 这是一个文件路径,即/etc/fstab文件,用于存储文件系统表。
# swapoff -a: 这个命令用于关闭所有启用的交换分区。
# sysctl -w vm.swappiness=0: 这个命令用于修改vm.swappiness参数的值为0,表示系统在物理内存充足时更倾向于使用物理内存而非交换分区。

1.3.5、时间同步

#加到计划任务每5分钟同步一次时间
echo "5 * * * *    ntpdate ntp1.aliyun.com" > /var/spool/cron/root

#同步时间
/usr/sbin/ntpdate ntp.aliyun.com

#同步到硬件时钟
hwclock --systohc

1.3.6、配置umilit

ulimit -SHn 65535
cat >> /etc/security/limits.conf <<EOF
* soft nofile 655360
* hard nofile 131072
* soft nproc 655350
* hard nproc 655350
* seft memlock unlimited
* hard memlock unlimitedd
EOF
 
# 参数解释
#
# soft nofile 655360
# soft表示软限制,nofile表示一个进程可打开的最大文件数,默认值为1024。这里的软限制设置为655360,即一个进程可打开的最大文件数为655360。
#
# hard nofile 131072
# hard表示硬限制,即系统设置的最大值。nofile表示一个进程可打开的最大文件数,默认值为4096。这里的硬限制设置为131072,即系统设置的最大文件数为131072。
#
# soft nproc 655350
# soft表示软限制,nproc表示一个用户可创建的最大进程数,默认值为30720。这里的软限制设置为655350,即一个用户可创建的最大进程数为655350。
#
# hard nproc 655350
# hard表示硬限制,即系统设置的最大值。nproc表示一个用户可创建的最大进程数,默认值为4096。这里的硬限制设置为655350,即系统设置的最大进程数为655350。
#
# seft memlock unlimited
# seft表示软限制,memlock表示一个进程可锁定在RAM中的最大内存,默认值为64 KB。这里的软限制设置为unlimited,即一个进程可锁定的最大内存为无限制。
#
# hard memlock unlimited
# hard表示硬限制,即系统设置的最大值。memlock表示一个进程可锁定在RAM中的最大内存,默认值为64 KB。这里的硬限制设置为unlimited,即系统设置的最大内存锁定为无限制。

1.3.7、 配置阿里yum源

# 配置CentOS 7 yum源
 
#配置centos源
#备份官方centos源
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
 
#下载阿里centos源
wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo
 
#配置epel源
wget -O /etc/yum.repos.d/epel.repo https://mirrors.aliyun.com/repo/epel-7.repo
 
#清除缓存
yum clean all
 
#生成新的缓存
yum makecache

1.3.8、修改内核参数

cat <<EOF > /etc/sysctl.d/k8s.conf
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-iptables = 1
fs.may_detach_mounts = 1
vm.overcommit_memory=1
vm.panic_on_oom=0
fs.inotify.max_user_watches=89100
fs.file-max=52706963
fs.nr_open=52706963
net.netfilter.nf_conntrack_max=2310720

net.ipv4.tcp_keepalive_time = 600
net.ipv4.tcp_keepalive_probes = 3
net.ipv4.tcp_keepalive_intvl =15
net.ipv4.tcp_max_tw_buckets = 36000
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_max_orphans = 327680
net.ipv4.tcp_orphan_retries = 3
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.ip_conntrack_max = 65536
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.tcp_timestamps = 0
net.core.somaxconn = 16384
EOF

sysctl --system

# 这些是Linux系统的一些参数设置,用于配置和优化网络、文件系统和虚拟内存等方面的功能。以下是每个参数的详细解释:
# 
# 1. net.ipv4.ip_forward = 1
#    - 这个参数启用了IPv4的IP转发功能,允许服务器作为网络路由器转发数据包。
# 
# 2. net.bridge.bridge-nf-call-iptables = 1
#    - 当使用网络桥接技术时,将数据包传递到iptables进行处理。
#   
# 3. fs.may_detach_mounts = 1
#    - 允许在挂载文件系统时,允许被其他进程使用。
#   
# 4. vm.overcommit_memory=1
#    - 该设置允许原始的内存过量分配策略,当系统的内存已经被完全使用时,系统仍然会分配额外的内存。
# 
# 5. vm.panic_on_oom=0
#    - 当系统内存不足(OOM)时,禁用系统崩溃和重启。
# 
# 6. fs.inotify.max_user_watches=89100
#    - 设置系统允许一个用户的inotify实例可以监控的文件数目的上限。
# 
# 7. fs.file-max=52706963
#    - 设置系统同时打开的文件数的上限。
# 
# 8. fs.nr_open=52706963
#    - 设置系统同时打开的文件描述符数的上限。
# 
# 9. net.netfilter.nf_conntrack_max=2310720
#    - 设置系统可以创建的网络连接跟踪表项的最大数量。
# 
# 10. net.ipv4.tcp_keepalive_time = 600
#     - 设置TCP套接字的空闲超时时间(秒),超过该时间没有活动数据时,内核会发送心跳包。
# 
# 11. net.ipv4.tcp_keepalive_probes = 3
#     - 设置未收到响应的TCP心跳探测次数。
# 
# 12. net.ipv4.tcp_keepalive_intvl = 15
#     - 设置TCP心跳探测的时间间隔(秒)。
# 
# 13. net.ipv4.tcp_max_tw_buckets = 36000
#     - 设置系统可以使用的TIME_WAIT套接字的最大数量。
# 
# 14. net.ipv4.tcp_tw_reuse = 1
#     - 启用TIME_WAIT套接字的重新利用,允许新的套接字使用旧的TIME_WAIT套接字。
# 
# 15. net.ipv4.tcp_max_orphans = 327680
#     - 设置系统可以同时存在的TCP套接字垃圾回收包裹数的最大数量。
# 
# 16. net.ipv4.tcp_orphan_retries = 3
#     - 设置系统对于孤立的TCP套接字的重试次数。
# 
# 17. net.ipv4.tcp_syncookies = 1
#     - 启用TCP SYN cookies保护,用于防止SYN洪泛攻击。
# 
# 18. net.ipv4.tcp_max_syn_backlog = 16384
#     - 设置新的TCP连接的半连接数(半连接队列)的最大长度。
# 
# 19. net.ipv4.ip_conntrack_max = 65536
#     - 设置系统可以创建的网络连接跟踪表项的最大数量。
# 
# 20. net.ipv4.tcp_timestamps = 0
#     - 关闭TCP时间戳功能,用于提供更好的安全性。
# 
# 21. net.core.somaxconn = 16384
#     - 设置系统核心层的连接队列的最大值。

1.3.9、配置免密登录

yum install -y sshpass
ssh-keygen -f /root/.ssh/id_rsa -P ''
export IP="192.168.100.31 192.168.100.32 192.168.100.33 192.168.100.34 192.168.100.35 192.168.100.36"
export SSHPASS=086530
for HOST in $IP;do
     sshpass -e ssh-copy-id -o StrictHostKeyChecking=no $HOST
done
 
 
# 这段脚本的作用是在一台机器上安装sshpass工具,并通过sshpass自动将本机的SSH公钥复制到多个远程主机上,以实现无需手动输入密码的SSH登录。
# 
# 具体解释如下:
# 
# 1. `apt install -y sshpass` 或 `yum install -y sshpass`:通过包管理器(apt或yum)安装sshpass工具,使得后续可以使用sshpass命令。
# 
# 2. `ssh-keygen -f /root/.ssh/id_rsa -P ''`:生成SSH密钥对。该命令会在/root/.ssh目录下生成私钥文件id_rsa和公钥文件id_rsa.pub,同时不设置密码(即-P参数后面为空),方便后续通过ssh-copy-id命令自动复制公钥。
# 
# 3. `export IP="192.168.100.31 192.168.100.32 192.168.100.33 192.168.100.34 192.168.100.35 192.168.100.36"`:设置一个包含多个远程主机IP地址的环境变量IP,用空格分隔开,表示要将SSH公钥复制到这些远程主机上。
# 
# 4. `export SSHPASS=086530`:设置环境变量SSHPASS,将sshpass所需的SSH密码(在这里是"086530")赋值给它,这样sshpass命令可以自动使用这个密码进行登录。
# 
# 5. `for HOST in $IP;do`:遍历环境变量IP中的每个IP地址,并将当前IP地址赋值给变量HOST。
# 
# 6. `sshpass -e ssh-copy-id -o StrictHostKeyChecking=no $HOST`:使用sshpass工具复制本机的SSH公钥到远程主机。其中,-e选项表示使用环境变量中的密码(即SSHPASS)进行登录,-o StrictHostKeyChecking=no选项表示连接时不检查远程主机的公钥,以避免交互式确认。
# 
# 通过这段脚本,可以方便地将本机的SSH公钥复制到多个远程主机上,实现无需手动输入密码的SSH登录。

1.3.10、设置主机名

hostnamectl set-hostname k8s-master01
hostnamectl set-hostname k8s-master02
hostnamectl set-hostname k8s-node01
hostnamectl set-hostname k8s-node02
hostnamectl set-hostname nginx-master
hostnamectl set-hostname nginx-backup

1.3.11、所有节点配置hosts本地解析

cat > /etc/hosts <<EOF
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
 
192.168.100.31 k8s-master01
192.168.100.32 k8s-master02
192.168.100.33 k8s-node01
192.168.100.34 k8s-node02
192.168.100.35 nginx-master
192.168.100.36 nginx-backup
192.168.100.37 lb-vip
EOF

二、部署Etcd集群

Etcd 是一个分布式键值存储系统, Kubernetes使用Etcd进行数据存储,所以先准备一个Etcd数据库,为解决Etcd单点故障,应采用集群方式部署,这里使用3台组建集群,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。

 

K8s二进制软件包v1.18下载:

链接:https://pan.baidu.com/s/19qAlXFwgeajy8-mHvmMKug 
提取码:nvzb

 

k8s-master01、k8s-node01、k8s-node02三台机器安装

2.1、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Master01节点。

cd K8s二进制软件包v1.18/

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

2.2、生成Etcd证书

2.2.1、自签证书颁发机构(CA)

创建工作目录:

mkdir -p ~/TLS/{etcd,k8s}

cd ~/TLS/etcd

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 -

ls *pem
ca-key.pem  ca.pem

2.2.2、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": [
    "192.168.100.31",
    "192.168.100.33",
    "192.168.100.34",
    "192.168.100.38",
    "192.168.100.39"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "BeiJing",
            "ST": "BeiJing"
        }
    ]
}                      
EOF



#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(192.168.100.38,192.168.100.39为预留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

ls server*pem
server-key.pem  server.pem

2.3、 部署Etcd集群

以下在k8s-master01上操作,为简化操作,待会将k8s-master01生成的所有文件拷贝到k8s-node01节点和k8s-node02节点.

2.3.1、 创建工作目录并解压二进制包

cd K8s二进制软件包v1.18/

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/

2.3.2、创建etcd配置文件

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://192.168.100.31:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.100.31:2379"

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.100.31:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.100.31:2379"
ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.100.31:2380,etcd-2=https://192.168.100.33:2380,etcd-3=https://192.168.100.34:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
EOF


说明:
#ETCD_NAME:节点名称,集群中唯一
#ETCD_DATA_DIR:数据目录
#ETCD_LISTEN_PEER_URLS:集群通信监听地址
#ETCD_LISTEN_CLIENT_URLS:客户端访问监听地址
#ETCD_INITIAL_ADVERTISE_PEER_URLS:集群通告地址
#ETCD_ADVERTISE_CLIENT_URLS:客户端通告地址
#ETCD_INITIAL_CLUSTER:集群节点地址
#ETCD_INITIAL_CLUSTER_TOKEN:集群Token
#ETCD_INITIAL_CLUSTER_STATE:加入集群的当前状态,new是新集群,existing表示加入已有集群

2.3.3、systemd管理etcd

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

2.3.4、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 ~/TLS/etcd/ca*pem  ~/TLS/etcd/server*pem  /opt/etcd/ssl/

2.3.5、将k8s-master01节点所有生成的文件拷贝到k8s-node01节点和k8s-node02节点

scp -r /opt/etcd/ root@192.168.100.33:/opt/

scp /usr/lib/systemd/system/etcd.service root@192.168.100.33:/usr/lib/systemd/system/

scp -r /opt/etcd/ root@192.168.100.34:/opt/

scp /usr/lib/systemd/system/etcd.service root@192.168.100.34:/usr/lib/systemd/system/

然后在k8s-node01节点和k8s-node02节点分别修改etcd.conf配置文件中的节点名称和当前服务器IP:

vim /opt/etcd/cfg/etcd.conf
#[Member]
ETCD_NAME="etcd-1"   # 修改此处,k8s-node01节点改为etcd-2,k8s-node02节点改为etcd-3
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.100.31:2380"   # 修改此处为当前服务器IP
ETCD_LISTEN_CLIENT_URLS="https://192.168.100.31:2379" # 修改此处为当前服务器IP

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.100.31:2380" # 修改此处为当前服务器IP
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.100.31:2379" # 修改此处为当前服务器IP
ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.100.31:2380,etcd-2=https://192.168.100.33:2380,etcd-3=https://192.168.100.34:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"

2.3.6、启动并设置开机启动

systemctl daemon-reload
systemctl start etcd
systemctl enable etcd

2.3.7、查看集群状态

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://192.168.100.31:2379,https://192.168.100.33:2379,https://192.168.100.34:2379" endpoint health --write-out=table

+-----------------------------+--------+-------------+-------+
|          ENDPOINT           | HEALTH |    TOOK     | ERROR |
+-----------------------------+--------+-------------+-------+
| https://192.168.100.31:2379 |   true | 22.913584ms |       |
| https://192.168.100.33:2379 |   true | 25.470072ms |       |
| https://192.168.100.34:2379 |   true | 25.793772ms |       |
+-----------------------------+--------+-------------+-------+

三、安装Docker

以下在所有节点操作。这里采用二进制安装,用yum安装也一样。

3.1、解压docker二进制包

tar zxvf docker-19.03.9.tgz
mv docker/* /usr/bin

3.2、systemd管理docker

cat > /usr/lib/systemd/system/docker.service << EOF
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target firewalld.service
Wants=network-online.target

[Service]
Type=notify
ExecStart=/usr/bin/dockerd
ExecReload=/bin/kill -s HUP $MAINPID
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
TimeoutStartSec=0
Delegate=yes
KillMode=process
Restart=on-failure
StartLimitBurst=3
StartLimitInterval=60s

[Install]
WantedBy=multi-user.target
EOF

3.3、创建配置文件

mkdir /etc/docker
cat > /etc/docker/daemon.json << EOF
{
  "registry-mirrors": ["https://b9pmyelo.mirror.aliyuncs.com"]
}
EOF

3.4、启动并设置开机启动

systemctl daemon-reload
systemctl start docker
systemctl enable docker

四、部署Master Node

4.1 、生成kube-apiserver证书

4.1.1、自签证书颁发机构(CA)

cd ~/TLS/k8s/

cat > ca-config.json << EOF
{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "kubernetes": {
         "expiry": "87600h",
         "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ]
      }
    }
  }
}
EOF
cat > ca-csr.json << EOF
{
    "CN": "kubernetes",
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "Beijing",
            "ST": "Beijing",
            "O": "k8s",
            "OU": "System"
        }
    ]
}
EOF

生成证书:

cfssl gencert -initca ca-csr.json | cfssljson -bare ca -

ls *pem
ca-key.pem  ca.pem

4.1.2、使用自签CA签发kube-apiserver HTTPS证书

创建证书申请文件:

cat > server-csr.json << EOF
{
    "CN": "kubernetes",
    "hosts": [
      "10.0.0.1",
      "127.0.0.1",
      "192.168.100.31",
      "192.168.100.33",
      "192.168.100.34",
      "192.168.100.35",
      "192.168.100.36",
      "192.168.100.37",
      "192.168.100.38",
      "192.168.100.39",
      "kubernetes",
      "kubernetes.default",
      "kubernetes.default.svc",
      "kubernetes.default.svc.cluster",
      "kubernetes.default.svc.cluster.local"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "BeiJing",
            "ST": "BeiJing",
            "O": "k8s",
            "OU": "System"
        }
    ]
}                           
EOF

注:上述文件hosts字段中IP为所有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(192.168.100.38和192.168.100.39为预留IP)。

生成证书:

cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes server-csr.json | cfssljson -bare server

ls server*pem
server-key.pem  server.pem

4.2、 解压kubernetes-server二进制包

cd K8s二进制软件包v1.18/
mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs} 
tar zxvf kubernetes-server-linux-amd64.tar.gz
cd kubernetes/server/bin
cp kube-apiserver kube-scheduler kube-controller-manager /opt/kubernetes/bin
cp kubectl /usr/bin/

4.2.1、创建配置文件

cat > /opt/kubernetes/cfg/kube-apiserver.conf << EOF
KUBE_APISERVER_OPTS="--logtostderr=false \
--v=2 \
--log-dir=/opt/kubernetes/logs \
--etcd-servers=https://192.168.100.31:2379,https://192.168.100.33:2379,https://192.168.100.34:2379 \
--bind-address=192.168.100.31 \
--secure-port=6443 \
--advertise-address=192.168.100.31 \
--allow-privileged=true \
--service-cluster-ip-range=10.0.0.0/24 \
--enable-admission-plugins=NamespaceLifecycle,LimitRanger,ServiceAccount,ResourceQuota,NodeRestriction \
--authorization-mode=RBAC,Node \
--enable-bootstrap-token-auth=true \
--token-auth-file=/opt/kubernetes/cfg/token.csv \
--service-node-port-range=30000-32767 \
--kubelet-client-certificate=/opt/kubernetes/ssl/server.pem \
--kubelet-client-key=/opt/kubernetes/ssl/server-key.pem \
--tls-cert-file=/opt/kubernetes/ssl/server.pem  \
--tls-private-key-file=/opt/kubernetes/ssl/server-key.pem \
--client-ca-file=/opt/kubernetes/ssl/ca.pem \
--service-account-key-file=/opt/kubernetes/ssl/ca-key.pem \
--etcd-cafile=/opt/etcd/ssl/ca.pem \
--etcd-certfile=/opt/etcd/ssl/server.pem \
--etcd-keyfile=/opt/etcd/ssl/server-key.pem \
--audit-log-maxage=30 \
--audit-log-maxbackup=3 \
--audit-log-maxsize=100 \
--audit-log-path=/opt/kubernetes/logs/k8s-audit.log"
EOF

注:上面两个\ \ 第一个是转义符,第二个是换行符,使用转义符是为了使用EOF保留换行符。
•	--logtostderr:启用日志
•	---v:日志等级
•	--log-dir:日志目录
•	--etcd-servers:etcd集群地址
•	--bind-address:监听地址
•	--secure-port:https安全端口
•	--advertise-address:集群通告地址
•	--allow-privileged:启用授权
•	--service-cluster-ip-range:Service虚拟IP地址段
•	--enable-admission-plugins:准入控制模块
•	--authorization-mode:认证授权,启用RBAC授权和节点自管理
•	--enable-bootstrap-token-auth:启用TLS bootstrap机制
•	--token-auth-file:bootstrap token文件
•	--service-node-port-range:Service nodeport类型默认分配端口范围
•	--kubelet-client-xxx:apiserver访问kubelet客户端证书
•	--tls-xxx-file:apiserver https证书
•	1.20版本必须加的参数:--service-account-issuer,--service-account-signing-key-file
•	--etcd-xxxfile:连接Etcd集群证书
•	--audit-log-xxx:审计日志
•	启动聚合层相关配置:--requestheader-client-ca-file,--proxy-client-cert-file,--proxy-client-key-file,--requestheader-allowed-names,--requestheader-extra-headers-prefix,--requestheader-group-headers,--requestheader-username-headers,--enable-aggregator-routing

4.2.2、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 ~/TLS/k8s/ca*pem ~/TLS/k8s/server*pem /opt/kubernetes/ssl/

4.2.3、启用 TLS Bootstrapping 机制 

TLS Bootstraping:Master apiserver启用TLS认证后,Node节点kubelet和kube-proxy要与kube-apiserver进行通信,必须使用CA签发的有效证书才可以,当Node节点很多时,这种客户端证书颁发需要大量工作,同样也会增加集群扩展复杂度。为了简化流程,Kubernetes引入了TLS bootstraping机制来自动颁发客户端证书,kubelet会以一个低权限用户自动向apiserver申请证书,kubelet的证书由apiserver动态签署。所以强烈建议在Node上使用这种方式,目前主要用于kubelet,kube-proxy还是由我们统一颁发一个证书。

TLS bootstraping 工作流程:

创建上述配置文件中token文件:

cat > /opt/kubernetes/cfg/token.csv << EOF
c47ffb939f5ca36231d9e3121a252940,kubelet-bootstrap,10001,"system:node-bootstrapper"
EOF

格式:token,用户名,UID,用户组

token也可自行生成替换:

head -c 16 /dev/urandom | od -An -t x | tr -d ' '

4.2.4、systemd管理apiserver 

cat > /usr/lib/systemd/system/kube-apiserver.service << EOF
[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/kubernetes/kubernetes

[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-apiserver.conf
ExecStart=/opt/kubernetes/bin/kube-apiserver \$KUBE_APISERVER_OPTS
Restart=on-failure

[Install]
WantedBy=multi-user.target
EOF

4.2.5、启动并设置开机启动 

systemctl daemon-reload
systemctl start kube-apiserver
systemctl enable kube-apiserver

4.2.6、授权kubelet-bootstrap用户允许请求证书

kubectl create clusterrolebinding kubelet-bootstrap \
--clusterrole=system:node-bootstrapper \
--user=kubelet-bootstrap

4.3、部署kube-controller-manager 

4.3.1、创建配置文件 

cat > /opt/kubernetes/cfg/kube-controller-manager.conf << EOF
KUBE_CONTROLLER_MANAGER_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--leader-elect=true \\
--master=127.0.0.1:8080 \\
--bind-address=127.0.0.1 \\
--allocate-node-cidrs=true \\
--cluster-cidr=10.244.0.0/16 \\
--service-cluster-ip-range=10.0.0.0/24 \\
--cluster-signing-cert-file=/opt/kubernetes/ssl/ca.pem \\
--cluster-signing-key-file=/opt/kubernetes/ssl/ca-key.pem  \\
--root-ca-file=/opt/kubernetes/ssl/ca.pem \\
--service-account-private-key-file=/opt/kubernetes/ssl/ca-key.pem \\
--experimental-cluster-signing-duration=87600h0m0s"
EOF

•	--kubeconfig:连接apiserver配置文件
•	--leader-elect:当该组件启动多个时,自动选举(HA)
•	--cluster-signing-cert-file/--cluster-signing-key-file:自动为kubelet颁发证书的CA,与apiserver保持一致

4.3.2、systemd管理controller-manager

cat > /usr/lib/systemd/system/kube-controller-manager.service << EOF
[Unit]
Description=Kubernetes Controller Manager
Documentation=https://github.com/kubernetes/kubernetes
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-controller-manager.conf
ExecStart=/opt/kubernetes/bin/kube-controller-manager \$KUBE_CONTROLLER_MANAGER_OPTS
Restart=on-failure
[Install]
WantedBy=multi-user.target
EOF

4.3.3、 启动并设置开机启动

systemctl daemon-reload
systemctl start kube-controller-manager
systemctl enable kube-controller-manager

4.4、部署kube-scheduler

4.4.1、创建配置文件

cat > /opt/kubernetes/cfg/kube-scheduler.conf << EOF
KUBE_SCHEDULER_OPTS="--logtostderr=false \
--v=2 \
--log-dir=/opt/kubernetes/logs \
--leader-elect \
--master=127.0.0.1:8080 \
--bind-address=127.0.0.1"
EOF

–master:通过本地非安全本地端口8080连接apiserver。

–leader-elect:当该组件启动多个时,自动选举(HA)

4.4.2、systemd管理scheduler

cat > /usr/lib/systemd/system/kube-scheduler.service << EOF
[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/kubernetes/kubernetes
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-scheduler.conf
ExecStart=/opt/kubernetes/bin/kube-scheduler \$KUBE_SCHEDULER_OPTS
Restart=on-failure
[Install]
WantedBy=multi-user.target
EOF

4.4.3、启动并设为开机自启

systemctl daemon-reload
systemctl start kube-scheduler
systemctl enable kube-scheduler

4.4.4、查看集群状态

kubectl get cs
NAME                 STATUS    MESSAGE             ERROR
controller-manager   Healthy   ok                  
scheduler            Healthy   ok                  
etcd-1               Healthy   {"health":"true"}   
etcd-0               Healthy   {"health":"true"}   
etcd-2               Healthy   {"health":"true"} 

#如上输出说明Master节点组件运行正常。

五、部署Worker Node

注意!!!下面还是在k8s-master01节点上操作,即同时作为Worker Node

5.1、 创建工作目录并拷贝二进制文件

在所有worker node创建工作目录:

mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs} 

将kube-proxy文件拷贝到/opt/kubernetes/bin目录下:

cp ~/K8s二进制软件包v1.18/kubernetes/server/bin/{kube-proxy,kubelet} /opt/kubernetes/bin

5.2、部署kubelet

5.2.1、创建配置文件

cat > /opt/kubernetes/cfg/kubelet.conf << EOF
KUBELET_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--hostname-override=k8s-master1 \\
--network-plugin=cni \\
--kubeconfig=/opt/kubernetes/cfg/kubelet.kubeconfig \\
--bootstrap-kubeconfig=/opt/kubernetes/cfg/bootstrap.kubeconfig \\
--config=/opt/kubernetes/cfg/kubelet-config.yml \\
--cert-dir=/opt/kubernetes/ssl \\
--pod-infra-container-image=lizhenliang/pause-amd64:3.0"
EOF


•	--hostname-override:显示名称,集群中唯一
•	--network-plugin:启用CNI
•	--kubeconfig:空路径,会自动生成,后面用于连接apiserver
•	--bootstrap-kubeconfig:首次启动向apiserver申请证书
•	--config:配置参数文件
•	--cert-dir:kubelet证书生成目录
•	--pod-infra-container-image:管理Pod网络容器的镜像

5.2.2、配置参数文件

cat > /opt/kubernetes/cfg/kubelet-config.yml << EOF
kind: KubeletConfiguration
apiVersion: kubelet.config.k8s.io/v1beta1
address: 0.0.0.0
port: 10250
readOnlyPort: 10255
cgroupDriver: cgroupfs
clusterDNS:
- 10.0.0.2
clusterDomain: cluster.local 
failSwapOn: false
authentication:
  anonymous:
    enabled: false
  webhook:
    cacheTTL: 2m0s
    enabled: true
  x509:
    clientCAFile: /opt/kubernetes/ssl/ca.pem 
authorization:
  mode: Webhook
  webhook:
    cacheAuthorizedTTL: 5m0s
    cacheUnauthorizedTTL: 30s
evictionHard:
  imagefs.available: 15%
  memory.available: 100Mi
  nodefs.available: 10%
  nodefs.inodesFree: 5%
maxOpenFiles: 1000000
maxPods: 110
EOF

5.2.3、生成bootstrap.kubeconfig文件

# apiserver IP:PORT
KUBE_APISERVER="https://192.168.100.31:6443" 

# 与token.csv里保持一致
TOKEN="c47ffb939f5ca36231d9e3121a252940" 

# 生成 kubelet bootstrap kubeconfig 配置文件
kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=bootstrap.kubeconfig
kubectl config set-credentials "kubelet-bootstrap" \
  --token=${TOKEN} \
  --kubeconfig=bootstrap.kubeconfig
kubectl config set-context default \
  --cluster=kubernetes \
  --user="kubelet-bootstrap" \
  --kubeconfig=bootstrap.kubeconfig
  
kubectl config use-context default --kubeconfig=bootstrap.kubeconfig

#拷贝到配置文件路径:
cp bootstrap.kubeconfig /opt/kubernetes/cfg

5.2.4、systemd管理kubelet

cat > /usr/lib/systemd/system/kubelet.service << EOF
[Unit]
Description=Kubernetes Kubelet
After=docker.service

[Service]
EnvironmentFile=/opt/kubernetes/cfg/kubelet.conf
ExecStart=/opt/kubernetes/bin/kubelet \$KUBELET_OPTS
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF

 5.2.5、启动并设置开机启动

systemctl daemon-reload
systemctl start kubelet
systemctl enable kubelet

 5.3、批准kubelet证书申请并加入集群

# 查看kubelet证书请求
kubectl get csr
NAME                                                   AGE   SIGNERNAME                                    REQUESTOR           CONDITION
node-csr--zye9OtuaCCQgTb0JzUATHLek9yIOa1xs3YxaTpvTQ4   44s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending

#批准申请
kubectl certificate approve node-csr--zye9OtuaCCQgTb0JzUATHLek9yIOa1xs3YxaTpvTQ4
certificatesigningrequest.certificates.k8s.io/node-csr--zye9OtuaCCQgTb0JzUATHLek9yIOa1xs3YxaTpvTQ4 approved

#查看节点
kubectl get node

注:由于网络插件还没有部署,节点会没有准备就绪 NotReady

5.4、部署kube-proxy

5.4.1、创建配置文件

cat > /opt/kubernetes/cfg/kube-proxy.conf << EOF
KUBE_PROXY_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--config=/opt/kubernetes/cfg/kube-proxy-config.yml"
EOF

5.4.2、配置文件参数

cat > /opt/kubernetes/cfg/kube-proxy-config.yml << EOF
kind: KubeProxyConfiguration
apiVersion: kubeproxy.config.k8s.io/v1alpha1
bindAddress: 0.0.0.0
metricsBindAddress: 0.0.0.0:10249
clientConnection:
  kubeconfig: /opt/kubernetes/cfg/kube-proxy.kubeconfig
hostnameOverride: k8s-master1
clusterCIDR: 10.0.0.0/24
EOF

5.4.3、生成kube-proxy.kubeconfig文件

生成kube-proxy证书:

# 切换工作目录
cd ~/TLS/k8s

# 创建证书请求文件
cat > kube-proxy-csr.json << EOF
{
  "CN": "system:kube-proxy",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "L": "BeiJing",
      "ST": "BeiJing",
      "O": "k8s",
      "OU": "System"
    }
  ]
}
EOF

#生成证书
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-proxy-csr.json | cfssljson -bare kube-proxy

ls kube-proxy*pem
kube-proxy-key.pem  kube-proxy.pem

#生成kubeconfig文件:
KUBE_APISERVER="https://192.168.100.31:6443"

kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=kube-proxy.kubeconfig
kubectl config set-credentials kube-proxy \
  --client-certificate=./kube-proxy.pem \
  --client-key=./kube-proxy-key.pem \
  --embed-certs=true \
  --kubeconfig=kube-proxy.kubeconfig
kubectl config set-context default \
  --cluster=kubernetes \
  --user=kube-proxy \
  --kubeconfig=kube-proxy.kubeconfig
kubectl config use-context default --kubeconfig=kube-proxy.kubeconfig

#拷贝到配置文件指定路径:
cp kube-proxy.kubeconfig /opt/kubernetes/cfg/

5.4.4、systemd管理kube-proxy

cat > /usr/lib/systemd/system/kube-proxy.service << EOF
[Unit]
Description=Kubernetes Proxy
After=network.target
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-proxy.conf
ExecStart=/opt/kubernetes/bin/kube-proxy \$KUBE_PROXY_OPTS
Restart=on-failure
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
EOF

5.4.5、启动并设置开机启动

systemctl daemon-reload
systemctl start kube-proxy
systemctl enable kube-proxy

5.5、部署CNI网络

5.5.1、解压二进制包并移动到默认工作目录:

mkdir /opt/cni/bin
tar zxvf cni-plugins-linux-amd64-v0.8.6.tgz -C /opt/cni/bin

5.5.2、部署CNI网络:

cd ~/K8s二进制软件包v1.18/

#默认镜像地址无法访问,修改为docker hub镜像仓库。
sed -i -r "s#quay.io/coreos/flannel:.*-amd64#lizhenliang/flannel:v0.12.0-amd64#g" kube-flannel.yml

kubectl apply -f kube-flannel.yml

kubectl get pods -n kube-system
NAME                          READY   STATUS    RESTARTS   AGE
kube-flannel-ds-amd64-jr7n6   1/1     Running   2          45h


kubectl get node
NAME          STATUS   ROLES    AGE   VERSION
k8s-master1   Ready    <none>   45h   v1.18.3


#部署好网络插件,Node准备就绪。

5.5.3、授权apiserver访问kubelet

cat > apiserver-to-kubelet-rbac.yaml << EOF
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  annotations:
    rbac.authorization.kubernetes.io/autoupdate: "true"
  labels:
    kubernetes.io/bootstrapping: rbac-defaults
  name: system:kube-apiserver-to-kubelet
rules:
  - apiGroups:
      - ""
    resources:
      - nodes/proxy
      - nodes/stats
      - nodes/log
      - nodes/spec
      - nodes/metrics
      - pods/log
    verbs:
      - "*"
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: system:kube-apiserver
  namespace: ""
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: system:kube-apiserver-to-kubelet
subjects:
  - apiGroup: rbac.authorization.k8s.io
    kind: User
    name: kubernetes
EOF

kubectl apply -f apiserver-to-kubelet-rbac.yaml

 5.6、新增加Worker Node

 5.6.1、拷贝已部署好的Node相关文件到新节点

 在master节点将Worker Node涉及文件拷贝到新节点192.168.100.33/34

scp -r /opt/kubernetes root@192.168.100.33:/opt/

scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service root@192.168.100.33:/usr/lib/systemd/system

scp -r /opt/cni/ root@192.168.100.33:/opt/

scp /opt/kubernetes/ssl/ca.pem root@192.168.100.33:/opt/kubernetes/ssl

 5.6.2、删除kubelet证书和kubeconfig文件

rm /opt/kubernetes/cfg/kubelet.kubeconfig 
rm -f /opt/kubernetes/ssl/kubelet*

#注:这几个文件是证书申请审批后自动生成的,每个Node不同,必须删除重新生成。

 5.6.3、修改主机名

vim /opt/kubernetes/cfg/kubelet.conf
--hostname-override=k8s-node1

vim /opt/kubernetes/cfg/kube-proxy-config.yml
hostnameOverride: k8s-node1

 5.6.4、启动并设为开机自启

systemctl daemon-reload
systemctl start kubelet
systemctl enable kubelet
systemctl start kube-proxy
systemctl enable kube-proxy

 5.6.5、在Master上批准新Node kubelet证书申请

kubectl get csr
NAME                                                   AGE   SIGNERNAME                                    REQUESTOR           CONDITION
node-csr-0wcuEkD-p05qjNZCfK9RKGsQdXcjG3FN8Pnpa_xmQ10   46h   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Approved,Issued

kubectl certificate approve node-csr-0wcuEkD-p05qjNZCfK9RKGsQdXcjG3FN8Pnpa_xmQ10

5.6.6、查看node状态

kubectl get node
NAME          STATUS   ROLES    AGE   VERSION
k8s-master1   Ready    <none>   46h   v1.18.3
k8s-node1     Ready    <none>   45h   v1.18.3
k8s-node2     Ready    <none>   45h   v1.18.3

Node2(192.168.100.34 )节点同上。记得修改主机名!

六、部署Dashboard和CoreDNS

6.1、部署Dashboard

默认Dashboard只能集群内部访问,修改Service为NodePort类型,暴露到外部

cat kubernetes-dashboard.yaml
...
---

kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
spec:
  ports:
    - port: 443
      targetPort: 8443
      nodePort: 30001
  type: NodePort
  selector:
    k8s-app: kubernetes-dashboard

---
...

kubectl apply -f kubernetes-dashboard.yaml

kubectl get pods,svc -n kubernetes-dashboard
NAME                                             READY   STATUS    RESTARTS   AGE
pod/dashboard-metrics-scraper-694557449d-7wqww   1/1     Running   2          45h
pod/kubernetes-dashboard-7548ffc8b7-lxljl        1/1     Running   2          45h

NAME                           TYPE       CLUSTER-IP   EXTERNAL-IP   PORT(S)         AGE
service/kubernetes-dashboard   NodePort   10.0.0.117   <none>        443:30001/TCP   45h

#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。

 

 6.2、部署CoreDNS

 CoreDNS用于集群内部Service名称解析。

kubectl apply -f coredns.yaml
 
kubectl get pods -n kube-system 
NAME                          READY   STATUS    RESTARTS   AGE
coredns-5ffbfd976d-lg96h      1/1     Running   2          45h
kube-flannel-ds-amd64-jr7n6   1/1     Running   2          45h
kube-flannel-ds-amd64-rzwn4   1/1     Running   2          45h
kube-flannel-ds-amd64-sft8r   1/1     Running   2          46h
kube-flannel-ds-amd64-xcjln   1/1     Running   2          45h

 DNS解析测试:

kubectl run -it --rm dns-test --image=busybox:1.28.4 sh
If you don't see a command prompt, try pressing enter.

/ # nslookup kubernetes
Server:    10.0.0.2
Address 1: 10.0.0.2 kube-dns.kube-system.svc.cluster.local

Name:      kubernetes
Address 1: 10.0.0.1 kubernetes.default.svc.cluster.local

解析没问题。

至此,单Master集群部署完成,下一步扩容为多Master集群~

七、高可用架构(扩容多Master架构)

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Etcd我们已经采用3个节点组建集群实现高可用,本节将对Master节点高可用进行说明和实施。

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-mansger和kube-scheduler,其中kube-controller-mansger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。

多Master架构图:

7.1、安装docker

同上

7.2、部署Master2 Node(192.168.100.32)

Master2 与已部署的Master1所有操作一致。所以我们只需将Master1所有K8s文件拷贝过来,再修改下服务器IP和主机名启动即可。

7.2.1、创建etcd证书目录

在Master2创建etcd证书目录

mkdir -p /opt/etcd/ssl

7.2.2、拷贝文件(在Master1操作)

拷贝Master1上所有K8s文件和etcd证书到Master2:

scp -r /opt/kubernetes root@192.168.100.32:/opt
scp -r /opt/cni/ root@192.168.100.32:/opt
scp -r /opt/etcd/ssl root@192.168.100.32:/opt/etcd
scp /usr/lib/systemd/system/kube* root@192.168.100.32:/usr/lib/systemd/system
scp /usr/bin/kubectl  root@192.168.100.32:/usr/bin

7.2.3、删除证书文件

删除kubelet证书和kubeconfig文件:

rm -f /opt/kubernetes/cfg/kubelet.kubeconfig
rm -f /opt/kubernetes/ssl/kubelet*

7.2.4、修改配置文件IP和主机名

修改apiserver、kubelet和kube-proxy配置文件为本地IP:

vim /opt/kubernetes/cfg/kube-apiserver.conf
...
--bind-address=192.168.100.32 \
--advertise-address=192.168.100.32 \
...

vim /opt/kubernetes/cfg/kubelet.conf
--hostname-override=k8s-master2

vim /opt/kubernetes/cfg/kube-proxy-config.yml
hostnameOverride: k8s-master2

7.2.5、启动设置开机启动

systemctl daemon-reload
systemctl start kube-apiserver
systemctl start kube-controller-manager
systemctl start kube-scheduler
systemctl start kubelet
systemctl start kube-proxy
systemctl enable kube-apiserver
systemctl enable kube-controller-manager
systemctl enable kube-scheduler
systemctl enable kubelet
systemctl enable kube-proxy

7.2.6、查看集群状态

kubectl get cs
NAME                 STATUS    MESSAGE             ERROR
scheduler            Healthy   ok                  
controller-manager   Healthy   ok                  
etcd-1               Healthy   {"health":"true"}   
etcd-2               Healthy   {"health":"true"}   
etcd-0               Healthy   {"health":"true"} 

7.2.7、批准kubelet证书申请

kubectl get csr

kubectl certificate approve node-csr-PCDrLAD1dA8azZmUr5qWLuJfDGq6U7994pytidbUfMk

kubectl get node
NAME          STATUS   ROLES    AGE   VERSION
k8s-master1   Ready    <none>   46h   v1.18.3
k8s-master2   Ready    <none>   45h   v1.18.3
k8s-node1     Ready    <none>   46h   v1.18.3
k8s-node2     Ready    <none>   46h   v1.18.3

7.3、部署nginx负载均衡器

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。

7.3.1、安装软件包(主/备)

yum install epel-release -y
yum install nginx keepalived -y
yum -y install nginx-all-modules.noarch

7.3.2、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 192.168.100.31:6443;   # Master1 APISERVER IP:PORT
       server 192.168.100.32:6443;   # Master2 APISERVER IP:PORT
    }
    
    server {
       listen 6443;
       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

7.3.3、keepalived配置文件(Nginx Master)

cat > /etc/keepalived/keepalived.conf << EOF
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 ens33
    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 {
        192.168.100.37/24
    }
    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)

检查nginx状态脚本:

cat > /etc/keepalived/check_nginx.sh  << "EOF"
#!/bin/bash
count=$(ps -ef |grep nginx |egrep -cv "grep|$$")

if [ "$count" -eq 0 ];then
    exit 1
else
    exit 0
fi
EOF
chmod +x /etc/keepalived/check_nginx.sh

7.3.4、keepalived配置文件(Nginx Backup)

cat > /etc/keepalived/keepalived.conf << EOF
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 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 {
        192.168.100.37/24
    }
    track_script {
        check_nginx
    }
}
EOF

上述配置文件中检查nginx运行状态脚本:

cat > /etc/keepalived/check_nginx.sh  << "EOF"
#!/bin/bash
count=$(ps -ef |grep nginx |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。

7.3.5、启动并设置开机启动

systemctl daemon-reload
systemctl start nginx
systemctl start keepalived
systemctl enable nginx
systemctl enable keepalived

7.3.6、查看keepalived工作状态

ip a
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:29:21:e1:da brd ff:ff:ff:ff:ff:ff
    inet 192.168.100.35/24 brd 192.168.100.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet 192.168.100.37/24 scope global secondary ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::9c33:6951:42ac:86ca/64 scope link noprefixroute 
       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。

7.3.7、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。

7.3.8、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:

[root@k8s-node1 ~]# curl -k https://192.168.100.37:6443/version
{
  "major": "1",
  "minor": "18",
  "gitVersion": "v1.18.3",
  "gitCommit": "2e7996e3e2712684bc73f0dec0200d64eec7fe40",
  "gitTreeState": "clean",
  "buildDate": "2020-05-20T12:43:34Z",
  "goVersion": "go1.13.9",
  "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:

[root@nginx-master ~]# tail /var/log/nginx/k8s-access.log -f
192.168.100.31 192.168.100.31:6443 - [28/Oct/2023:00:58:26 +0800] 200 427
192.168.100.2 192.168.100.32:6443 - [28/Oct/2023:01:00:43 +0800] 200 669
192.168.100.2 192.168.100.31:6443 - [28/Oct/2023:01:03:49 +0800] 200 1502
192.168.100.31 192.168.100.31:6443 - [28/Oct/2023:01:12:15 +0800] 200 427
192.168.100.33 192.168.100.31:6443 - [29/Oct/2023:22:37:41 +0800] 200 427

到此还没结束,还有下面最关键的一步

7.4、修改所有Worker Node连接LB VIP

试想下,虽然我们增加了Master2和负载均衡器,但是我们是从单Master架构扩容的,也就是说目前所有的Node组件连接都还是Master1,如果不改为连接VIP走负载均衡器,那么Master还是单点故障。

因此接下来就是要改所有Node组件配置文件,由原来192.168.100.31修改为192.168.100.37(VIP):

也就是通过kubectl get node命令查看到的节点。

在上述所有Worker Node执行:

sed -i 's#192.168.100.31:6443#192.168.100.37:6443#' /opt/kubernetes/cfg/*
systemctl restart kubelet
systemctl restart kube-proxy

检查节点状态:

kubectl get node
NAME          STATUS   ROLES    AGE   VERSION
k8s-master1   Ready    <none>   46h   v1.18.3
k8s-master2   Ready    <none>   45h   v1.18.3
k8s-node1     Ready    <none>   46h   v1.18.3
k8s-node2     Ready    <none>   46h   v1.18.3

至此,一套完整的 Kubernetes 高可用集群就部署完成了!

PS:如果你是在公有云上,一般都不支持keepalived,那么你可以直接用它们的负载均衡器产品(内网就行,还免费~),架构与上面一样,直接负载均衡多台Master kube-apiserver即可!

 

posted @ 2023-10-19 00:18  我的城市没有海  阅读(159)  评论(0)    收藏  举报