```sh
# 设置变量
alias cp='cp'
centos7_iso='https://mirrors.tuna.tsinghua.edu.cn/centos/7.9.2009/os/x86_64/'
ubuntu_iso'https://mirrors.tuna.tsinghua.edu.cn/ubuntu-releases/22.04/ubuntu-22.04.2-live-server-amd64.iso'
dhip=$(ip addr |grep inet -w|awk -F' ' '{print $2}'|sed -n '2p' |awk -F'/' '{print $1}')
dhipNet=$(echo ${dhip:0:-$(expr length `echo $dhip |cut -d '.' -f4`)})
dhipStart=${dhipNet}100
dhipEnd=${dhipNet}200

# 关闭selinux
echo '- 关闭selinux'
setenforce 0
sed -i 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config
# 关闭防火墙
echo '- 关闭防火墙'
systemctl stop firewalld
# 安装软件
echo -e '开始安装tftp/xinetd/vsftpd/syslinux...\n'
yum install tftp-server xinetd vsftpd syslinux-4.05 dhcp-4.2.5 -y > /dev/null

if [ ! -e /var/ftp/centos7 ]
then 
    mkdir -p /var/ftp/centos7
elif [ ! -e /mnt/centos7 ]
then
    mkdir -p /mnt/centos7
fi
mount -o loop /dev/sr0 /mnt/centos7
if [[ $? -eq 0 || -s /mnt/centos7/isolinux ]]
then
    echo '拷贝镜像文件到ftp目录下'
    cp -rf /mnt/centos7/* /var/ftp/centos7/
else
    echo -e '未挂载iso文件,将使用华为镜像站镜像!\n'
    # 在华为镜像站下载启动文件,也可以用本地iso镜像里的文件,拷贝到/var/lib/tftpboot目录即可
    echo '开始下载初始化文件'
    wget -P /var/lib/tftpboot/ --no-check-certificate ${centos7_iso}images/pxeboot/initrd.img
    echo '开始下载内核文件'
    wget -P /var/lib/tftpboot/ --no-check-certificate ${centos7_iso}images/pxeboot/vmlinuz

fi
sed -i 's/yes/no/g' /etc/xinetd.d/tftp
# grep -v "^#" /usr/share/doc/dhcp-4.2.5/dhcpd.conf.example |grep -v "^$"| grep -v "opt*" |head -n5

# 配置dhcp
cat > /etc/dhcp/dhcpd.conf << EOF
log-facility local7;
ignore client-updates;
# 创建地址池
subnet ${dhipNet}0 netmask 255.255.255.0{
    range ${dhipStart} ${dhipEnd}; #地址池
    option routers ${dhip}; # 网关地址
    ddns-update-style none; # 禁止ddns动态更新
    next-server ${dhip}; # 服务器地址
    filename "pxelinux.0"; # 指定pxe引导文件
    default-lease-time 600;
    max-lease-time 7200;
}
EOF
# 拷贝引导程序
cp /usr/share/syslinux/pxelinux.0 /var/lib/tftpboot/
cp /usr/share/syslinux/menu.c32  /var/lib/tftpboot/

# 配置引导文件
cat > /var/lib/tftpboot/pxelinux.cfg/default << EOF
#UI menu.c32
default centos7 local
prompt 1
timeout 5
label centos7 local
    kernel vmlinuz  
    append initrd=initrd.img method=ftp://${dhip}/centos7
label centos7 net
    kernel vmlinuz
    append initrd=initrd.img method=${centos7_iso} # ks=ftp
EOF
# 设置开机自启,并重新启动
systemctl enable --now tftp vsftpd dhcpd xinetd
systemctl restart tftp vsftpd dhcpd xinetd
if [ $? -eq 0 ]
then
    echo 'pxe引导服务搭建成功!'
fi
```

## 无人值守引导配置
```sh
#platform=x86, AMD64, 或 Intel EM64T
#version=DEVEL
# Install OS instead of upgrade
install
# Keyboard layouts
keyboard 'us'
# Root password
rootpw --iscrypted $1$RrxYwvA3$RQQcS4Mas0Ef.TqS0Ptot/
# System language
lang en_US.UTF-8 --addsupport=zh_CN.UTF-8
# System authorization information
auth  --useshadow  --passalgo=sha512
# Use text mode install
text
# SELinux configuration
selinux --disabled
# Do not configure the X Window System
skipx


# Firewall configuration
firewall --disabled
# Network information
network  --bootproto=dhcp --device=eth0
# Reboot after installation
reboot
# System timezone
timezone Asia/Shanghai
# Use network installation
url --url="http://https://repo.huaweicloud.com/centos/7.9.2009/os/x86_64/"
# url --url=ftp://<user>:<password>@<server>/<path>

#platform=x86, AMD64, 或 Intel EM64T
#version=DEVEL
# Install OS instead of upgrade
install
# Keyboard layouts
keyboard 'us'
# Root password
rootpw --iscrypted $1$RrxYwvA3$RQQcS4Mas0Ef.TqS0Ptot/
# System language
lang en_US.UTF-8 --addsupport=zh_CN.UTF-8
# System authorization information
auth  --useshadow  --passalgo=sha512
# Use text mode install
text
# SELinux configuration
selinux --disabled
# Do not configure the X Window System
skipx


# Firewall configuration
firewall --disabled
# Network information
network  --bootproto=dhcp --device=eth0
# Reboot after installation
reboot
# System timezone
timezone Asia/Shanghai
# Use network installation
#url="http://https://repo.huaweicloud.com/centos/7.9.2009/os/x86_64/"
url --url=ftp://192.168.225.133/centos7

# System bootloader configuration
bootloader --location=mbr
# Clear the Master Boot Record
zerombr
# Partition clearing information
ignoredisk --only-use=sda
clearpart --all --initlabel
# Disk partitioning information
part /boot --fstype="xfs" --asprimary --size=2048
part /  --fstype="xfs" --grow --asprimary --size=1

services --enabled="sshd,network"

# 安装软件包
%packages
network-tools
openssh
openssl-devel
wget

%end

# 系统安装前运行程序
%pre --interpreter=/bin/bash
echo 'centos7 install'
%end

# 系统安装后运行程序
%post --interpreter=/bin/bash

wget -O /etc/yum.repos.d/CentOS-Base.repo https://repo.huaweicloud.com/repository/conf/CentOS-7-
reg.repo
%end

```