Simple Python Script to Edit an Ubuntu ISO to Add Automated Server Install Capability

edit_ubuntu_autoinstall.py

import io
import pathlib

import pycdlib

ubuntu = pathlib.Path('ubuntu-22.04.1-live-server-amd64.iso')
new_iso_path = pathlib.Path('ubuntu-22.04.1-live-server-amd64-auto.iso')

iso = pycdlib.PyCdlib()
iso.open(ubuntu)

extracted = io.BytesIO()
iso.get_file_from_iso_fp(extracted, iso_path='/BOOT/GRUB/GRUB.CFG;1')
extracted.seek(0)
data = extracted.read()
print(data.decode())

new = data.replace(b' ---', b'quiet autoinstall ds=nocloud\;s=/cdrom/nocloud/ ---')
print(new.decode())

iso.rm_file(iso_path='/BOOT/GRUB/GRUB.CFG;1', rr_name='grub.cfg')
iso.add_fp(io.BytesIO(new), len(new), '/BOOT/GRUB/GRUB.CFG;1', rr_name='grub.cfg')

iso.add_directory('/NOCLOUD', rr_name='nocloud')

user_data = b"""#cloud-config
autoinstall:
  version: 1
  identity:
    hostname: ubuntu-server
    password: "$6$exDY1mhS4KUYCE/2$zmn9ToZwTKLhCw.b4/b.ZRTIZM30JZ4QrOQ2aOXJ8yk96xpcCof0kxKwuX1kqLG/ygbJ1f8wxED22bTL4F46P0"
    username: ubuntu
"""

iso.add_fp(io.BytesIO(user_data), len(user_data), '/NOCLOUD/USER_DATA;1', rr_name='user-data')
iso.add_fp(io.BytesIO(b''), len(b''), '/NOCLOUD/META_DATA;1', rr_name='meta-data')
iso.write(new_iso_path)
iso.close()

edit_ubuntu_autoinstall_simple.py

import io
import pathlib

import pycdlib

ubuntu = pathlib.Path('ubuntu-22.04.1-live-server-amd64.iso')
new_iso = pathlib.Path('ubuntu-22.04.1-live-server-amd64-auto.iso')

iso = pycdlib.PyCdlib()
iso.open(ubuntu)

extracted = io.BytesIO()
iso.get_file_from_iso_fp(extracted, iso_path='/BOOT/GRUB/GRUB.CFG;1')
extracted.seek(0)
data = extracted.read()
print(data.decode())

new = data.replace(b' ---', b'quiet autoinstall ---').replace(b'timeout=30', b'timeout=1')
print(new.decode())

iso.rm_file(iso_path='/BOOT/GRUB/GRUB.CFG;1', rr_name='grub.cfg')
iso.add_fp(io.BytesIO(new), len(new), '/BOOT/GRUB/GRUB.CFG;1', rr_name='grub.cfg')

iso.write(new_iso)
iso.close()

make_cloud_init_data_iso.py

import io
import pathlib

import pycdlib

new_iso = pathlib.Path('ubuntu-22.04-auto.iso')

iso = pycdlib.PyCdlib()
iso.new(rock_ridge='1.09', vol_ident='CIDATA')

user_data = b"""#cloud-config
autoinstall:
  version: 1
  identity:
    hostname: ubuntu-server
    password: "$6$exDY1mhS4KUYCE/2$zmn9ToZwTKLhCw.b4/b.ZRTIZM30JZ4QrOQ2aOXJ8yk96xpcCof0kxKwuX1kqLG/ygbJ1f8wxED22bTL4F46P0"
    username: ubuntu
"""

iso.add_fp(io.BytesIO(user_data), len(user_data), '/USERDATA;1', rr_name='user-data')
iso.add_fp(io.BytesIO(b''), len(b''), '/METADATA;1', rr_name='meta-data')

iso.write(new_iso)
iso.close()

Thanks, I personally don't require a verification check. I just happened to notice during the process it was failing validation from the change to the grub.cfg. Thanks for posting the additional content to disable the check and thanks for your work! Made my life easier that's for sure :)

Made some modifications to disable the verifications for future reference.

import io
import pathlib

import pycdlib

ubuntu = pathlib.Path('ubuntu-20.04.5-live-server-amd64.iso')
new_iso = pathlib.Path('ubuntu-20.04.5-live-server-amd64-auto.iso')

iso = pycdlib.PyCdlib()
iso.open(ubuntu)

extracted = io.BytesIO()
iso.get_file_from_iso_fp(extracted, iso_path='/BOOT/GRUB/GRUB.CFG;1')
extracted.seek(0)
data = extracted.read()
print(data.decode())

new = data.replace(b'Install Ubuntu Server', b'Autoinstall Ubuntu Server - Disabled Verfification').replace(b' ---', b'quiet autoinstall fsck.mode=skip ---').replace(b'timeout=30', b'timeout=1')
print(new.decode())

iso.rm_file(iso_path='/BOOT/GRUB/GRUB.CFG;1', rr_name='grub.cfg')
iso.add_fp(io.BytesIO(new), len(new), '/BOOT/GRUB/GRUB.CFG;1', rr_name='grub.cfg')

iso.write(new_iso)
iso.close()