15.系统自动部署

1 基于centos8实现PXE自动安装系统

红帽官方文档：

https://access.redhat.com/documentation/zh-cn/red_hat_enterprise_linux/7/html/installation_guide/chap-installation-server-setup#sect-network-boot-setup-bios

Syslinux参考站点：

https://wiki.syslinux.org/wiki/index.php?title=PXELINUX#Description

https://wiki.archlinux.org/index.php/Syslinux_(简体中文)

1.1 安装前准备

关闭防火墙和SELINUX，DHCP服务器静态IP

网络要求：关闭Vmware软件中的DHCP服务，基于NAT模式

主机分配：将所有服务安装在同一台服务器中

实现centos8的自动安装

1.2 安装相关软件包

#安装软件包
[root@centos8 ~]# yum -y install dhcp-server tftp-server httpd syslinux-nonlinux

#启动服务
[root@centos8 ~]# systemctl enable --now httpd tftp

#查看是否启动成功
[root@centos8 ~]# ss -ntul
Netid      State       Recv-Q      Send-Q            Local Address:Port             Peer Address:Port      
udp        UNCONN      0           0                             *:69               *:*         
tcp        LISTEN      0           128                     0.0.0.0:22             0.0.0.0:*     
tcp        LISTEN      0           128                           *:80               *:*         
tcp        LISTEN      0           128                        [::]:22               [::]:*

1.3 配置DHCP服务

#默认/etc下dhcp文件是空的，所以先拷贝范例配置文件便于配置
[root@centos8 ~]# cp /usr/share/doc/dhcp-server/dhcpd.conf.example /etc/dhcp/dhcpd.conf

#配置DHCP
[root@centos8 ~]# ip a
1: ens160: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:0c:29:ed:28:61 brd ff:ff:ff:ff:ff:ff
    inet 10.0.0.100/24 scope global ens160
       valid_lft forever preferred_lft forever

[root@centos8 ~]# vim /etc/dhcp/dhcpd.conf 	#注意不要丢失尾部分号，否则启动不了服务
option domain-name "example.org";
option domain-name-servers ns1.example.org, ns2.example.org;

default-lease-time 600;
max-lease-time 7200;
log-facility local7;

subnet 10.0.0.0 netmask 255.255.255.0 {
 range 10.0.0.1 10.0.0.200;
 option routers 10.0.0.1;
 next-server 10.0.0.100;
 filename "pxelinux.0";
}

#启动dhcp服务
[root@centos8 ~]# systemctl start dhcpd

1.4 准备yum 源和相关目录

#创建文件夹
[root@centos8 ~]# mkdir -pv /var/www/html/centos/8/os/x86_64/
mkdir: created directory '/var/www/html/centos'
mkdir: created directory '/var/www/html/centos/8'
mkdir: created directory '/var/www/html/centos/8/os'
mkdir: created directory '/var/www/html/centos/8/os/x86_64/'
[root@centos8 ~]# ll /var/www/html/centos/8/os/x86_64/ -d
drwxr-xr-x. 2 root root 6 Apr 29 01:52 /var/www/html/centos/8/os/x86_64/

#挂载本地光盘
[root@centos8 ~]# mount /dev/sr0 /var/www/html/centos/8/os/x86_64/
mount: /var/www/html/centos/8/os/x86_64: WARNING: device write-protected, mounted read-only.

#这时我们可以访问http://10.0.0.100/centos/8/os/x86_64/来验证是否成功

1.5 准备PXE启动相关文件

#创建文件夹
[root@centos8 ~]# mkdir /var/lib/tftpboot/centos8

#复制内核文件至tftp目录
[root@centos8 ~]# cp /var/www/html/centos/8/os/x86_64/isolinux/{vmlinuz,initrd.img} /var/lib/tftpboot/centos8/

#复制syslinux相关文件至tftp
[root@centos8 ~]# cp /usr/share/syslinux/{pxelinux.0,ldlinux.c32,menu.c32,libcom32.c32,libutil.c32} /var/lib/tftpboot/
[root@centos8 ~]# ll /var/lib/tftpboot/
total 160
drwxr-xr-x. 2 root root     39 Apr 30 00:02 centos8
-rw-r--r--. 1 root root 116096 Apr 30 01:05 ldlinux.c32
-rw-r--r--. 1 root root  42791 Apr 30 01:05 pxelinux.0

#生成菜单文件
[root@centos8 ~]# mkdir /var/lib/tftpboot/pxelinux.cfg/
[root@centos8 ~]# cp /var/www/html/centos/8/os/x86_64/isolinux/isolinux.cfg /var/lib/tftpboot/pxelinux.cfg/default

1.6 准备kickstart文件

[root@centos8 ~]# mkdir /var/www/html/ks
[root@centos8 ~]# cat /var/www/html/ks/centos8.cfg 
ignoredisk --only-use=sda
zerombr
text
reboot
clearpart --all --initlabel
selinux --disabled
firewall --disabled
url --url=http://10.0.0.100/centos/8/os/x86_64/
keyboard --vckeymap=us --xlayouts='us'
lang en_US.UTF-8
network  --bootproto=dhcp --device=ens160 --ipv6=auto --activate
network  --hostname=centos8.magedu.com
rootpw --iscrypted $6$18lCu5Jb7ncPFxK2$xu15Q3igR6OmU71EiUxuzEv7eic7sYdSmhE7kuRfZ8VfqwCrm/0AbojEgvIz0KXg4HntKbufBmnx/dgqsSvOY.
firstboot --enable
skipx
services --disabled="chronyd"
timezone Asia/Shanghai --isUtc --nontp
part / --fstype="xfs" --ondisk=sda --size=102400
part /data --fstype="xfs" --ondisk=sda --size=51200
part swap --fstype="swap" --ondisk=sda --size=2048
part /boot --fstype="ext4" --ondisk=sda --size=1024
%packages
@^minimal-environment
kexec-tools
%end
%addon com_redhat_kdump --enable --reserve-mb='auto'
%end
%anaconda
pwpolicy root --minlen=6 --minquality=1 --notstrict --nochanges --notempty
pwpolicy user --minlen=6 --minquality=1 --notstrict --nochanges --emptyok
pwpolicy luks --minlen=6 --minquality=1 --notstrict --nochanges --notempty
%end
%post
useradd test1
%end

1.7 配置启动菜单文件

[root@centos8 ~]# vim /var/lib/tftpboot/pxelinux.cfg/default
[root@centos8 ~]# cat /var/lib/tftpboot/pxelinux.cfg/default 
default menu.c32
timeout 600

menu title CentOS Linux 8

label linux8
  menu label ^Install CentOS Linux 8
  kernel centos8/vmlinuz
  append initrd=centos8/initrd.img ks=http://10.0.0.100/ks/centos8.cfg

label manual
  menu label ^Manual Install CentOS Linux 8.0
  kernel centos8/vmlinuz
  append initrd=centos8/initrd.img
 inst.repo=http://10.0.0.100/centos/8/os/x86_64/ 

label rescue
  menu label ^Rescue a CentOS Linux system 8
  kernel centos8/vmlinuz
  append initrd=centos8/initrd.img
 inst.repo=http://10.0.0.100/centos/8/os/x86_64/ rescue
  
label local
  menu default
  menu label Boot from ^local drive
  localboot 0xffff

1.8 测试客户端基于PXE实现自动安装

菜单选择界面

系统自动安装完成后查看是否成功创建test1用户