void-minecraft-usb/opt/system-image

102 lines
2.9 KiB
Bash

#!/usr/bin/env bash
# used to work around cases where stdin is unavailable or not a terminal
if bash -c ': > /dev/tty' > /dev/null 2>&1; then
TTY_OR_CONSOLE="/dev/tty"
else
TTY_OR_CONSOLE="/dev/console"
fi
function echo_tty {
if [ "$1" = "-n" ]; then
shift
echo -n "$@" > $TTY_OR_CONSOLE
else
echo "$@" > $TTY_OR_CONSOLE
fi
}
function yesno {
unset DISCARD_ME
while [ -z "$DISCARD_ME" ]; do
read -p "[y/n] " -n1 DISCARD_ME < $TTY_OR_CONSOLE > $TTY_OR_CONSOLE
case "$DISCARD_ME" in
y)
echo_tty
return 0
;;
n)
echo_tty
return 1
;;
*)
echo_tty " Please enter y for yes or n for no."
unset DISCARD_ME
;;
esac
done
}
#TODO: refuse to run if system is running
#TODO: add a way to force a new system image without asking (for example a file in /run/void-usb)
#TODO: colors (bright white / light gray for readability)
echo_tty "Create a new system image?
This will replace the existing system image with a snapshot of the currently
running system. Choosing no here will discard any newly installed programs,
updates, system configuration changes, etc.
This should not affect your files in /home as they are stored to disk directly.
Check /TODO/README.txt for more information.
Creating a new system image will take some time.
"
if yesno; then
echo_tty -n "Generating exclusion list... "
# cutting off the leading slash allows us to just ignore empty lines below
readarray -t MOUNT_LIST <<< "$(findmnt --output TARGET --noheadings --raw | sed -e 's|^/||' | sort)"
# always ignore /tmp and the package cache
EXCLUDE_LIST=("tmp" "var/cache/xbps")
for I in ${!MOUNT_LIST[@]}; do
if [ ! -z "${MOUNT_LIST[$I]}" ]; then
FOUND=0
for J in ${!EXCLUDE_LIST[@]}; do
if grep "${EXCLUDE_LIST[$J]}" > /dev/null <<< "${MOUNT_LIST[$I]}"; then
FOUND=1
break
fi
done
# if no parent dir of ${MOUNT_LIST[$I]} is found in $EXCLUDE_LIST
if [ $FOUND -eq 0 ]; then
EXCLUDE_LIST+=("${MOUNT_LIST[$I]}")
fi
fi
done
touch /run/void-usb/system-image-excludes
touch /run/void-usb/system-image-pseudo
for I in ${!EXCLUDE_LIST[@]}; do
echo "/${EXCLUDE_LIST[$I]}" >> /run/void-usb/system-image-excludes
FILE_PERMS="$(stat -c '%a %u %g' "${EXCLUDE_LIST[$I]}")"
echo "\"/${EXCLUDE_LIST[$I]}\" d $FILE_PERMS" >> /run/void-usb/system-image-pseudo
done
echo_tty "done"
echo_tty "Building image..."
mksquashfs / /run/void-usb/container/new_squashfs.img -b 1M -comp xz -progress -noappend -pf /run/void-usb/system-image-pseudo -ef /run/void-usb/system-image-excludes > $TTY_OR_CONSOLE
echo_tty -n "Moving new image in place... "
mv /run/void-usb/container/new_squashfs.img /run/void-usb/container/squashfs.img
echo_tty "done"
else
echo_tty "Discarding system changes."
fi
echo_tty -n "Syncing... "
sync
echo_tty "done"