#!/bin/bash

# Script to update and boot Ubuntu daily-live ISO with GRUB2

# Autor João Sousa tuxmind.blogspot.com

# Version 0.2 testado no Ubuntu 22.04 LTS

# Update 2022-04-17

### Find partition uuid where the iso file is

DEVICE=`df -h . | tail -1 | cut -d" " -f1`

ROOTUUID=`sudo blkid $DEVICE | awk -F 'UUID="' '{print $2}' | cut -d\" -f1`

### Install curl and zsync (Add repo "universe")

which curl || sudo apt-get install -y curl

which zsync || (sudo apt-get update; sudo add-apt-repository universe; sudo apt-get update; sudo apt-get install -y zsync)

### Find last "daily-live" codename (future URL changes will break this :( send me your feedback if you know a better way to do this :P )

codename=`curl -s https://cdimage.ubuntu.com/daily-live/current/SHA256SUMS | head -1 | cut -d* -f2 | cut -d- -f1`

cd

### zsync download/update ISO file

zsync http://cdimage.ubuntu.com/daily-live/current/$codename-desktop-amd64.iso.zsync && echo "Image $codename-desktop-amd64.iso is update"

### Remove simbolic link (only if exist)

rm -f Ubuntu-desktop-amd64.iso

### Simbolic link to Ubuntu-desktop-arm64.iso

ln -s $codename-desktop-amd64.iso Ubuntu-desktop-amd64.iso

### Separate home partition?

RAIZ=`echo "/$USER"`

### Or... same partition?

[ `df / | tail -1 | cut -d" " -f1` == `df /home | tail -1 | cut -d" " -f1` ] && RAIZ=`echo "/home/$USER"`

### Created "42_ubuntu-daily-live" (if doesn't exist)

if [ -e /etc/grub.d/42_ubuntu-daily-live ];

then

echo "42_ubuntu-daily-live ok"

else

### Add new boot option to Grub2

cat > 42_ubuntu-daily-live << EOF

#!/bin/sh

exec tail -n +3 \$0

menuentry "Ubuntu $codename Daily Live" {

insmod part_gpt

insmod ext2

if [ x$feature_platform_search_hint = xy ]; then

search --no-floppy --fs-uuid --set=root $ROOTUUID

else

search --no-floppy --fs-uuid --set=root $ROOTUUID

fi

set isofile="$RAIZ/Ubuntu-desktop-amd64.iso"

loopback loop \$isofile

linux (loop)/casper/vmlinuz root=UUID=$ROOTUUID boot=casper iso-scan/filename=\$isofile noprompt quiet splash --

initrd (loop)/casper/initrd.lz

}

EOF

### Move file "42_ubuntu-daily-live" to /etc/grub.d

sudo mv 42_ubuntu-daily-live /etc/grub.d/42_ubuntu-daily-live

### Change permissions

sudo chmod +x /etc/grub.d/42_ubuntu-daily-live

### Update Grub menu list

sudo update-grub

fi