PXE

# install tftp,dhcp,syslinux
yum install -y tftp-server dhcp-server syslinux

# setup dhcp-server
# if you use virt-install to install vm, dhcp is not required.

# dhcpd.conf
#
# Sample configuration file for ISC dhcpd
#

# option definitions common to all supported networks...
option domain-name "example.org";
option domain-name-servers ns1.example.org, ns2.example.org;

default-lease-time 600;
max-lease-time 7200;

# Use this to enble / disable dynamic dns updates globally.
#ddns-update-style none;

# If this DHCP server is the official DHCP server for the local
# network, the authoritative directive should be uncommented.
#authoritative;

# Use this to send dhcp log messages to a different log file (you also
# have to hack syslog.conf to complete the redirection).
log-facility local7;

class "class1" {
    #match if substring(hardware, 1, 8) = "9e:d9:36";
    match if binary-to-ascii(16,8,":",substring(hardware, 1, 3)) = "9e:d9:36";
}

subnet 172.20.0.0 netmask 255.255.0.0 {
  allow members of "class1";
  range 172.20.0.1 172.20.0.10;
  next-server 172.20.0.254;
  filename "pxelinux.0";
}

host veth1 {
  hardware ethernet d6:c9:2b:3b:c5:15;
  fixed-address 172.20.0.11;
  next-server 172.20.0.254;
  filename "pxelinux.0";
}

# setup tftp-server

# download isolinux files to tftpboot directory
[root@mlxsw-sn2100-01 dhcp]# cd /var/lib/tftpboot/
[root@mlxsw-sn2100-01 tftpboot]# ll
total 70176
-rw-r--r--. 1 root root       84 Nov 20 11:56 boot.msg
-rw-r--r--. 1 root root      325 Nov 20 11:56 grub.conf
-rw-r--r--. 1 root root 63026896 Nov 20 11:56 initrd.img
-rw-r--r--. 1 root root    38912 Nov 20 11:56 isolinux.bin
-rw-r--r--. 1 root root    3159  Nov 20 11:57 isolinux.cfg
-rw-r--r--. 1 root root   116096 Sep 25 09:18 ldlinux.c32
-rw-r--r--. 1 root root   180700 Sep 25 09:18 libcom32.c32
-rw-r--r--. 1 root root    22804 Sep 25 09:18 libutil.c32
-rw-r--r--. 1 root root   182704 Aug 12  2018 memtest
-rw-r--r--. 1 root root    42821 Dec  3 05:28 pxelinux.0
drwxr-xr-x. 2 root root       41 Dec  8 00:53 pxelinux.cfg
-rw-r--r--. 1 root root      186 Aug 16 09:30 splash.png
-rw-r--r--. 1 root root    26788 Sep 25 09:18 vesamenu.c32
-rw-r--r--. 1 root root  8188560 Nov 15 13:59 vmlinuz

# create pxelinux.cfg directory
# cp isolinux.cfg to pxelinux.cfg/default
[root@mlxsw-sn2100-01 tftpboot]# mkdir pxelinux.cfg/
[root@mlxsw-sn2100-01 tftpboot]# cp isolinux.cfg pxelinux.cfg/default
[root@mlxsw-sn2100-01 tftpboot]# ll pxelinux.cfg/
total 8
-rw-r--r--. 1 root root 3233 Dec  8 00:46 default

# set kernel image, initrd, kickstart file in pxelinux.cfg/default
kernel vmlinuz
append initrd=initrd.img  console=ttyS0 ks=http://10.73.128.15/ks.cfg

# ks.cfg is provided by http server

[root@mlxsw-sn2100-01 tftpboot]# cd /var/www/html/
[root@mlxsw-sn2100-01 html]# cat ks.cfg 
#url --url http://192.168.122.1:80/rhel8.iso
url --url http://download.eng.pek2.xxx.com//rhel-8/rel-eng/RHEL-8/RHEL-8.2.0-20191120.0/compose/BaseOS/x86_64/os/
reboot
rootpw --plaintext foobar
services --enabled="sshd,chronyd"
zerombr
clearpart --all
autopart --type lvm
%packages
@core
%end

#%post
#cat <<"EOF" > /etc/yum.repos.d/yum.repo
#[rhel8.2]
#name=rhel8.2
#baseurl=http://10.73.2.112/rhel-8/rel-eng/RHEL-8/RHEL-8.2.0-20191120.0/compose/BaseOS/x86_64/os/
#enabled=1
#baseurl=http://download.eng.pek2.xxx.com/rhel-8/rel-eng/RHEL-8/RHEL-8.2.0-20191120.0/compose/BaseOS/x86_64/os/
#gpgcheck=0
#EOF
#%end

# I have no bare metal system, so i use virt-install to install vm

# virsh net-destroy default
# virsh net-edit default
<network>
  <name>default</name>
  <uuid>356e5daf-3b06-49d5-98fd-178e847cf559</uuid>
  <forward mode='nat'/>
  <bridge name='virbr0' stp='on' delay='0'/>
  <mac address='52:54:00:aa:da:73'/>
  <ip address='192.168.122.1' netmask='255.255.255.0'>
    <tftp root='/var/lib/tftpboot'/>
    <dhcp>
      <range start='192.168.122.2' end='192.168.122.254'/>
      <bootp file='pxelinux.0'/>
    </dhcp>
  </ip>
</network>

# virt-install --pxe --network network=default --name pxe --memory 2048 --disk size=10 --nographics --boot menu=on,useserial=on