Ubuntu 20.04.3 AutoInstall

HowTo

# For recent versions of Ubuntu:
 - https://www.pugetsystems.com/labs/hpc/ubuntu-22-04-server-autoinstall-iso/

# Docs:
 - https://wiki.ubuntu.com/FoundationsTeam/AutomatedServerInstalls
 - https://wiki.ubuntu.com/FoundationsTeam/AutomatedServerInstalls/ConfigReference
 - https://cloudinit.readthedocs.io/en/latest/topics/datasources/nocloud.html
 - https://discourse.ubuntu.com/t/please-test-autoinstalls-for-20-04/15250/53

# Download ISO Installer:
wget https://ubuntu.volia.net/ubuntu-releases/20.04.3/ubuntu-20.04.3-live-server-amd64.iso

# Create ISO distribution dirrectory:
mkdir -p iso/nocloud/

# Extract ISO using 7z:
7z x ubuntu-20.04.3-live-server-amd64.iso -x'![BOOT]' -oiso
# Or extract ISO using xorriso and fix permissions:
xorriso -osirrox on -indev "ubuntu-20.04.3-live-server-amd64.iso" -extract / iso && chmod -R +w iso

# Create empty meta-data file:
touch iso/nocloud/meta-data

# Copy user-data file:
cp user-data iso/nocloud/user-data

# Update boot flags with cloud-init autoinstall:
## Should look similar to this: initrd=/casper/initrd quiet autoinstall ds=nocloud;s=/cdrom/nocloud/ ---
sed -i 's|---|autoinstall ds=nocloud\\\;s=/cdrom/nocloud/ ---|g' iso/boot/grub/grub.cfg
sed -i 's|---|autoinstall ds=nocloud;s=/cdrom/nocloud/ ---|g' iso/isolinux/txt.cfg

# Disable mandatory md5 checksum on boot:
md5sum iso/.disk/info > iso/md5sum.txt
sed -i 's|iso/|./|g' iso/md5sum.txt

# (Optionally) Regenerate md5:
# The find will warn 'File system loop detected' and return non-zero exit status on the 'ubuntu' symlink to '.'
# To avoid that, temporarily move it out of the way
mv iso/ubuntu .
(cd iso; find '!' -name "md5sum.txt" '!' -path "./isolinux/*" -follow -type f -exec "$(which md5sum)" {} \; > ../md5sum.txt)
mv md5sum.txt iso/
mv ubuntu iso

# Create Install ISO from extracted dir (ArchLinux):
xorriso -as mkisofs -r \
  -V Ubuntu\ custom\ amd64 \
  -o ubuntu-20.04.3-live-server-amd64-autoinstall.iso \
  -J -l -b isolinux/isolinux.bin -c isolinux/boot.cat -no-emul-boot \
  -boot-load-size 4 -boot-info-table \
  -eltorito-alt-boot -e boot/grub/efi.img -no-emul-boot \
  -isohybrid-gpt-basdat -isohybrid-apm-hfsplus \
  -isohybrid-mbr /usr/lib/syslinux/bios/isohdpfx.bin  \
  iso/boot iso

# Create Install ISO from extracted dir (Ubuntu):
xorriso -as mkisofs -r \
  -V Ubuntu\ custom\ amd64 \
  -o ubuntu-20.04.3-live-server-amd64-autoinstall.iso \
  -J -l -b isolinux/isolinux.bin -c isolinux/boot.cat -no-emul-boot \
  -boot-load-size 4 -boot-info-table \
  -eltorito-alt-boot -e boot/grub/efi.img -no-emul-boot \
  -isohybrid-gpt-basdat -isohybrid-apm-hfsplus \
  -isohybrid-mbr /usr/lib/ISOLINUX/isohdpfx.bin  \
  iso/boot iso

# After install:
 - login with 'root:root' and change root user password
 - set correct hostname with 'hostnamectl'

user-data

#cloud-config
autoinstall:
  version: 1
  interactive-sections:
    - network
    - storage
  locale: en_US.UTF-8
  keyboard:
    layout: us
  ssh:
    allow-pw: true
    install-server: false
  late-commands:
    - curtin in-target --target=/target -- apt-get --purge -y --quiet=2 remove apport bcache-tools btrfs-progs byobu cloud-guest-utils cloud-initramfs-copymods cloud-initramfs-dyn-netconf friendly-recovery fwupd landscape-common lxd-agent-loader ntfs-3g open-vm-tools plymouth plymouth-theme-ubuntu-text popularity-contest rsync screen snapd sosreport tmux ufw
    - curtin in-target --target=/target -- apt-get --purge -y --quiet=2 autoremove
    - curtin in-target --target=/target -- apt-get clean
    - sed -i 's/ENABLED=1/ENABLED=0/' /target/etc/default/motd-news
    - sed -i 's|# en_US.UTF-8 UTF-8|en_US.UTF-8 UTF-8|' /target/etc/locale.gen
    - curtin in-target --target=/target -- locale-gen
    - ln -fs /dev/null /target/etc/systemd/system/connman.service
    - ln -fs /dev/null /target/etc/systemd/system/display-manager.service
    - ln -fs /dev/null /target/etc/systemd/system/motd-news.service
    - ln -fs /dev/null /target/etc/systemd/system/motd-news.timer
    - ln -fs /dev/null /target/etc/systemd/system/plymouth-quit-wait.service
    - ln -fs /dev/null /target/etc/systemd/system/plymouth-start.service
    - ln -fs /dev/null /target/etc/systemd/system/systemd-resolved.service
    - ln -fs /usr/share/zoneinfo/Europe/Kiev /target/etc/localtime
    - rm -f /target/etc/resolv.conf
    - printf 'nameserver 8.8.8.8\nnameserver 1.1.1.1\noptions timeout:1\noptions attempts:1\noptions rotate\n' > /target/etc/resolv.conf
    - rm -f /target/etc/update-motd.d/10-help-text
    - rm -rf /target/root/snap
    - rm -rf /target/snap
    - rm -rf /target/var/lib/snapd
    - rm -rf /target/var/snap
    - curtin in-target --target=/target -- passwd -q -u root
    - curtin in-target --target=/target -- passwd -q -x -1 root
    - curtin in-target --target=/target -- passwd -q -e root
    - sed -i 's|^root:.:|root:$6$3b873df474b55246$GIpSsujar7ihMzG8urUKpzF9/2yZJhR.msyFRa5ouGXOKRCVszsc4aBcE2yi3IuFVxtAGwrPKin2WAzK3qOtB.:|' /target/etc/shadow
  user-data:
    disable_root: false

user-data_with_ssh_and_project_quota

#cloud-config
autoinstall:
  version: 1
  interactive-sections:
    - network
    - storage
  locale: en_US.UTF-8
  keyboard:
    layout: us
  ssh:
    allow-pw: true
    install-server: false
  late-commands:
    - curtin in-target --target=/target -- apt-get --purge -y --quiet=2 remove apport bcache-tools btrfs-progs byobu cloud-guest-utils cloud-initramfs-copymods cloud-initramfs-dyn-netconf friendly-recovery fwupd landscape-common lxd-agent-loader ntfs-3g open-vm-tools plymouth plymouth-theme-ubuntu-text popularity-contest screen snapd sosreport tmux ufw
    - curtin in-target --target=/target -- apt-get -qq update
    - curtin in-target --target=/target -- apt-get -y install wget gnupg python2.7 openssh-server
    - curtin in-target --target=/target -- apt-get -qq update
    - curtin in-target --target=/target -- apt-get -y dist-upgrade
    - curtin in-target --target=/target -- apt-get --purge -y --quiet=2 autoremove
    - sed -i 's/#PermitRootLogin prohibit-password/PermitRootLogin yes/' /target/etc/ssh/sshd_config
    - sed -i 's/ENABLED=1/ENABLED=0/' /target/etc/default/motd-news
    - sed -i 's|# en_US.UTF-8 UTF-8|en_US.UTF-8 UTF-8|' /target/etc/locale.gen
    - curtin in-target --target=/target -- locale-gen
    - ln -fs /dev/null /target/etc/systemd/system/connman.service
    - ln -fs /dev/null /target/etc/systemd/system/display-manager.service
    - ln -fs /dev/null /target/etc/systemd/system/motd-news.service
    - ln -fs /dev/null /target/etc/systemd/system/motd-news.timer
    - ln -fs /dev/null /target/etc/systemd/system/plymouth-quit-wait.service
    - ln -fs /dev/null /target/etc/systemd/system/plymouth-start.service
    - ln -fs /dev/null /target/etc/systemd/system/systemd-resolved.service
    - ln -fs /usr/share/zoneinfo/Europe/Kiev /target/etc/localtime
    - rm -f /target/etc/resolv.conf
    - printf 'nameserver 8.8.8.8\nnameserver 1.1.1.1\noptions timeout:1\noptions attempts:1\noptions rotate\n' > /target/etc/resolv.conf
    - rm -f /target/etc/update-motd.d/10-help-text
    - rm -rf /target/root/snap
    - rm -rf /target/snap
    - rm -rf /target/var/lib/snapd
    - rm -rf /target/var/snap
    - curtin in-target --target=/target -- passwd -q -u root
    - curtin in-target --target=/target -- passwd -q -x -1 root
    - curtin in-target --target=/target -- passwd -q -e root
    - sed -i 's|^root:.:|root:$6$3b873df474b55246$GIpSsujar7ihMzG8urUKpzF9/2yZJhR.msyFRa5ouGXOKRCVszsc4aBcE2yi3IuFVxtAGwrPKin2WAzK3qOtB.:|' /target/etc/shadow
    - sed -i 's/ext4 defaults/ext4 prjquota,lazytime/g' /target/etc/fstab
    - findmnt --real -U -n -t ext4 -o source | awk '{system("umount -l "$1)}'
    - blkid -t TYPE="ext4" -o device | awk '{system("tune2fs -O project,quota -Q prjquota "$1)}'
  user-data:
    disable_root: false

The last line is an IPv6 address which we don't use so you can leave that alone.

Thank you!