Debian stretch headless install

This is my adaptation of this for debian stretch.

Mount the iso and copy the contents for rw.

Change the menu to load SSH on boot by default, edit isonew/isolinux/gtk.cfg (To see what file to edit in case of future changes you can run grep "menu default" isolinux/*)

I replaced the entire file with

default netinstall
label netinstall
    menu label ^Install Over SSH
    menu default
    kernel /install.amd/vmlinuz
    append auto=true vga=788 file=/cdrom/preseed.cfg initrd=/install.amd/initrd.gz locale=en_US console-keymaps-at/keymap=us

Generate isonew/preseed.cfg

#### Contents of the preconfiguration file
### Localization
# Locale sets language and country.
d-i debian-installer/locale select en_US
# Keyboard selection.
d-i console-keymaps-at/keymap select us
d-i keyboard-configuration/xkb-keymap select us
### Network configuration
# netcfg will choose an interface that has link if possible. This makes it
# skip displaying a list if there is more than one interface.
d-i netcfg/choose_interface select auto
# Any hostname and domain names assigned from dhcp take precedence over
# values set here. However, setting the values still prevents the questions
# from being shown, even if values come from dhcp.
d-i netcfg/get_hostname string newdebian
d-i netcfg/get_domain string local
# If non-free firmware is needed for the network or other hardware, you can
# configure the installer to always try to load it, without prompting. Or
# change to false to disable asking.
d-i hw-detect/load_firmware boolean true
# The wacky dhcp hostname that some ISPs use as a password of sorts.
#d-i netcfg/dhcp_hostname string radish
d-i preseed/early_command string anna-install network-console
# Setup ssh password
d-i network-console/password password install
d-i network-console/password-again password install

recreate md5sum.txt

chmod 666 md5sum.txt
find -follow -type f -exec md5sum {} \; > md5sum.txt
chmod 444 md5sum.txt

run inside isonew/

xorriso -as mkisofs -b isolinux/isolinux.bin -c isolinux/boot.cat -iso-level 3 -no-emul-boot -partition_offset 16 -boot-load-size 4 -boot-info-table -o ../debian-9.3.0-amd64-headless.iso ../isonew/

test with kvm -m 512 -cdrom debian-9.3.0-amd64-headless.iso