Files
grub-btrfs/41_snapshots-btrfs
2015-08-07 14:16:03 +02:00

225 lines
7.5 KiB
Bash

#! /usr/bin/bash
#
#
#########################################################################################################################################################
# Written by: Antynea #
# #
# Purpose: Include btrfs snapshots at boot options. #
# #
# What this script does: #
# - Automatically List snapshots existing on root partition (btrfs). #
# - Automatically Detect kernel, initramfs and intel microcode in "/boot" directory on snapshots. (For custon name, see below.) #
# - Automatically Create corresponding "menuentry" in grub.cfg , which ensures a very easy rollback. #
# #
# How to use it: #
# - Add this lines to /etc/default/grub: #
# #
# * GRUB_BTRFS_SUBMENUNAME="ArchLinux Snapshots" (Name menu appearing in grub.) #
# * GRUB_BTRFS_PREFIXENTRY="Snapshot:" (Add a name ahead your snapshots entries.) #
# * GRUB_BTRFS_NKERNEL=("vmlinuz-linux") (Use only if you have custom kernel name or auto-detect failed.) #
# * GRUB_BTRFS_NINIT=("initramfs-linux.img" "initramfs-linux-fallback.img") (Use only if you have custom initramfs name or auto-detect failed.) #
# * GRUB_BTRFS_INTEL_UCODE=("intel-ucode.img") (Use only if you have custom intel-ucode or auto-detect failed.) #
# #
# - Generate grub.cfg (on Archlinux use grub-mkconfig -o /boot/grub/grub.cfg ) #
# #
# - grub-btrfs automatically generates snapshots entries. #
# - You will see it appear different entries (e.g : Snapshot: my snapshot name overkill [2014-02-12 11:24:37]) #
# #
# Warning: #
# #
# Script in progress #
# to do : #
# # #
# * verify compatibility with manjaro and snapper (but I don't use them, so it will take some time) #
# #
#########################################################################################################################################################
set -e
#prefix="/usr"
#exec_prefix="${prefix}"
datarootdir="/usr/share"
#datadir="${datarootdir}"
sysconfdir="/etc"
. "${datarootdir}/grub/grub-mkconfig_lib"
. "${sysconfdir}/default/grub"
######################################
### variables in /etc/default/grub ###
######################################
## Choice of method
choise_of_method=${GRUB_BTRFS_SUBMENUNAME:-"1"}
## Submenu name
submenuname=${GRUB_BTRFS_SUBMENUNAME:-"ArchLinux Snapshots"}
## Prefix entry
prefixentry=${GRUB_BTRFS_PREFIXENTRY:-"Snapshot:"}
## Kernel(s) name(s)
nkernel=("${GRUB_BTRFS_NKERNEL[@]}")
## Initramfs name(s)
ninit=("${GRUB_BTRFS_NINIT[@]}")
## Microcode(s) name(s)
microcode=("${GRUB_BTRFS_INTEL_UCODE[@]:-intel-ucode.img}")
########################
### variables script ###
########################
## Internationalization (default : english)
export TEXTDOMAIN=grub-btrfs-git
export TEXTDOMAINDIR="/usr/share/locale"
## hints string
hs_boot=$(${grub_probe} --target="hints_string" "/boot" 2>/dev/null)
## UUID of the boot partition
boot_uuid=$(${grub_probe} --target="fs_uuid" "/boot" 2>/dev/null)
## Type filesystem of boot partition
boot_fs=$(${grub_probe} --target="fs" "/boot" 2>/dev/null)
## UUID of the root partition
root_uuid=$(${grub_probe} "/" --target="fs_uuid" 2>/dev/null)
## Parameters passed to the kernel
kernel_parameters="$GRUB_CMDLINE_LINUX $GRUB_CMDLINE_LINUX_DEFAULT"
## Mount point location
gbgmp="/tmp/gbgmp"
## Class for theme
CLASS="--class snapshots --class gnu-linux --class gnu --class os"
## save IFS
oldIFS=$IFS
## boot_dir (auto-detect if /boot is separate partition or not)
boot_dir()
{
boot_dir="$gbgmp/$snap_dir_name/boot"
[[ "$root_uuid" != "$boot_uuid" ]] && boot_dir="/boot"
echo "$boot_dir"
boot_dir_real_path="$(make_system_path_relative_to_its_root "$boot_dir")"
}
##############
### Script ###
##############
### BEGIN auto detect ###
## menu entries
snapshots_entry()
{
## \" required for snap,kernels,init,microcode with space in their name
echo " submenu '${1} ${2} ${3}' {"
for k in "${name_kernel[@]}"; do
for i in "${name_initramfs[@]}"; do
echo "\
menuentry '${2} with "${k}" & "${i}"' ${CLASS} "\$menuentry_id_option" 'gnulinux-snapshots-$boot_uuid'{
$(save_default_entry)
if [ x\$feature_all_video_module = xy ]; then
insmod all_video
fi
set gfxpayload=keep
insmod ${boot_fs}
if [ x\$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root ${hs_boot} ${boot_uuid}
else
search --no-floppy --fs-uuid --set=root ${boot_uuid}
fi
echo 'Loading Snapshot: "${snap_dir_name}" "${snap_date_time}"'
echo 'Loading Kernel: "${k}" ...'
linux \"${boot_dir_real_path}/"${k}"\" root=UUID=${root_uuid} rw rootflags=subvol=\""${snap_dir_name}"\" ${kernel_parameters}
echo 'Loading Initramfs: "${i}" ...'"
if [ -f "/${boot_dir_real_path}/"${microcode}"" ] ; then
echo "\
initrd \"${boot_dir_real_path}/"${microcode}"\" initrd \"/${snap_dir_name}/boot/"${i}"\""
else
echo "\
initrd \"${boot_dir_real_path}/"${i}"\""
fi
echo " }"
done
done
echo " }"
}
## List of snapshots on filesystem
snapshot_list()
{
for snap in $(btrfs subvolume list -sa /); do
IFS=$oldIFS
snap=($snap)
local snap_path_name=${snap[@]:13:${#snap[@]}}
# Discard deleted snapshots
if [ $snap_path_name = "DELETED" ]; then continue; fi
[[ ${snap_path_name%%"/"*} == "<FS_TREE>" ]] && snap_path_name=${snap_path_name#*"/"}
echo ${snap[@]:10:2} ${snap_path_name}
done
}
detect_kernel()
{
## Arch original kernel (auto-detect)
for akernel in $(boot_dir)/vmlinuz-* ; do
list_kernel+=("$akernel")
done
## Custom name kernel in GRUB_BTRFS_NKERNEL
if [ ! -z ${nkernel} ] ; then
for ckernel in "${nkernel[@]}" ; do
[[ ! -f /$(boot_dir)/${ckernel} ]] && continue;
list_kernel+=("$ckernel")
done
fi
}
detect_initramfs()
{
## Arch original kernel (auto-detect)
for ainitramfs in $(boot_dir)/initramfs-* ; do
list_initramfs+=("$ainitramfs")
done
## Custom name initramfs in GRUB_BTRFS_NINIT
if [ ! -z ${ninit} ] ; then
for cinitramfs in "${ninit[@]}" ; do
[[ ! -f /$(boot_dir)/${ninit} ]] && continue;
list_initramfs+=("$ninit")
done
fi
}
## List of kernels and initramfs in snapshots
list_kernels_initramfs()
{
if [ $root_uuid = $boot_uuid ] ; then
[[ ! -d $gbgmp ]] && mkdir -p $gbgmp
mount -o subvolid=0 /dev/disk/by-uuid/$root_uuid $gbgmp/
fi
IFS=$'\n'
for item in $(snapshot_list); do
IFS=$oldIFS
item=($item)
snap_dir_name=${item[@]:2:${#item[@]}}
if [ -f $(boot_dir)/grub/grub.cfg ]; then
snap_date_time=${item[@]:0:2}
gettext_printf $"# Found Snapshot: %s\n" "$snap_dir_name $snap_date_time" >&2 ;
unset list_kernel
detect_kernel
name_kernel=("${list_kernel[@]##*"/"}")
# echo "kernel = ${name_kernel[*]}"
unset list_initramfs
detect_initramfs
name_initramfs=("${list_initramfs[@]##*"/"}")
echo "initramfs = ${name_initramfs[*]}"
fi
# Create menu entries
# snapshots_entry "${prefixentry}" "${snap_dir_name}" "${snap_date_time}"
done
IFS=$oldIFS
if [ $root_uuid = $boot_uuid ] ; then umount $gbgmp ; fi
}
### END auto detect ###
### Choice of method ###
if [ ${choise_of_method} = "1" ] ; then
gettext_printf "###### - Grub-btrfs: Auto-detect - ######\n" >&2 ;
echo "submenu '${submenuname}' {"
list_kernels_initramfs ;
echo "}"
gettext_printf "###### - Grub-btrfs: Auto-detect - ######\n" >&2 ;
fi
### End choice of method ###