boot CoreOS and other images over the network, utilizing iPXE

netboot-server.service

[Unit]
Description=netboot server
Wants=network-online.target
After=network-online.target sys-subsystem-net-devices-ext0.device
AssertPathExists=/srv/ftp/tftproot

[Service]
Slice=machine.slice
KillMode=mixed
Restart=on-abort
# Resource limits
Delegate=true
CPUShares=512
MemoryLimit=256M

ExecStartPre=/usr/bin/mkdir --parents /var/lib/coreos
ExecStartPre=-/usr/bin/rkt rm --uuid-file=/var/lib/coreos/%p.uuid

ExecStart=/usr/bin/rkt run \
  --uuid-file-save=/var/lib/coreos/%p.uuid \
  --net=host --dns=host \
  --volume tftpboot,kind=host,source=/srv/ftp/tftproot \
  blitznote.com/aci/netboot-server-tftp \
  --caps-retain=CAP_SYS_CHROOT,CAP_NET_BIND_SERVICE,CAP_SETGID,CAP_SETUID \
  --readonly-rootfs=true \
  blitznote.com/aci/netboot-server-http \
  --caps-retain=CAP_SYS_CHROOT,CAP_NET_BIND_SERVICE,CAP_SETGID,CAP_SETUID \
  --readonly-rootfs=true

ExecStop=-/usr/bin/rkt stop --uuid-file=/var/lib/coreos/%p.uuid
ExecStopPost=-/usr/bin/rkt gc --mark-only

[Install]
WantedBy=multi-user.target

pxelinux.cfg-default

default vesamenu.c32
MENU WIDTH 80
MENU MARGIN 10
MENU ROWS 12
MENU ENDROW 24
MENU TIMEOUTROW 18
MENU VSHIFT 2

prompt 0
timeout 150
ontimeout coreos
menu title PXE Network Boot

label memtest86
  menu label Memtest86+ 5.01
  kernel ::images/memtest/memtest86+

label coreos
  menu default
  menu label CoreOS amd64 1465.4.0
  kernel ::coreos/1465.4.0/coreos_production_pxe.vmlinuz
  initrd ::coreos/1465.4.0/coreos_production_pxe_image.cpio.gz
  append sshkey="ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIHFUL/SXo3o6BAgGGI7ay+87n+r0ofH9x3vAVklfBLiU mark@surfdev" coreos.autologin=tty1

label winpe_10x64
  menu label Windows 10 PE x64
  kernel memdisk
  initrd http://192.168.1.555:69/images/winpe/WinPE_10x64.iso
  append iso raw