Add systemd.path as option to monitor for new Snapshots (#53)

* Use systemd.path to regenerate grub-btrfs.cfg

* Added option GRUB_BTRFS_DIRNAME

* Updated README

41_snapshots-btrfs

@@ -2,68 +2,39 @@
 #
 #
 #########################################################################################################################################################################
-# Written by: Antynea																																					#
+# Written by: Antynea
-# BTC donation address: 1Lbvz244WA8xbpHek9W2Y12cakM6rDe5Rt																												#
+# BTC donation address: 1Lbvz244WA8xbpHek9W2Y12cakM6rDe5Rt
-# Github: https://github.com/Antynea/grub-btrfs 																														#
+# Github: https://github.com/Antynea/grub-btrfs
-#                                                                                                                                                                       #
+#                                                                                                                                                                       
-# Purpose: Include btrfs snapshots at boot options (grub-menu).																											#
+# Purpose: Include btrfs snapshots at boot options (grub-menu).
-#																																										#
+#
-# What this script does:																																				#
+# What this script does:
-# Simple rollback using snapshots you made previously.																													#
+# Simple rollback using snapshots you made previously.
-# - Automatically List snapshots existing on root partition (btrfs).																									#
+# - Automatically List snapshots existing on root partition (btrfs).
-# - Automatically Detect if "/boot" is in separate partition.																											#
+# - Automatically Detect if "/boot" is in separate partition.
-# - Automatically Detect kernel, initramfs and intel microcode in "/boot" directory on snapshots.                               										#
+# - Automatically Detect kernel, initramfs and intel microcode in "/boot" directory on snapshots.
-# - Automatically Create corresponding "menuentry" in grub.cfg , which ensures a very easy rollback.																	#
+# - Automatically Create corresponding "menuentry" in grub.cfg , which ensures a very easy rollback.
-# - Automatically detect snapper and use snapper's snapshot description if available.																					#
+# - Automatically detect snapper and use snapper's snapshot description if available.
-#																																										#
+#
-# How to customize it:																																					#
+# How to customize it:
-# - Add this lines to /etc/default/grub:																																#
+# - Refer 41_snapshots-btrfs_config for the list of available options and their default values.
-#																																										#
+# - Place your configurations to either /etc/grub.d/41_snapshots-btrfs_config or /etc/default/grub.
-# * GRUB_BTRFS_SUBMENUNAME="Arch Linux snapshots" 																														#
+#
-#		(Name appearing in the Grub menu.)																																#
+# - Generate grub.cfg (on Arch Linux use grub-mkconfig -o /boot/$grub_directory/grub.cfg)
-# * GRUB_BTRFS_PREFIXENTRY="Snapshot:"        		   																													#
+#
-#		(Add a name ahead your snapshots entries in the Grub menu.) 																									#
+# - grub-btrfs automatically generates snapshots entries.
-# * GRUB_BTRFS_DISPLAY_PATH_SNAPSHOT="true"																																#
+# - You will see it appear different entries (e.g : Snapshot: [2014-02-12 11:24:37] my snapshot name overkill)
-#		(Show full path snapshot or only name in the Grub menu)																											#
+#
-# * GRUB_BTRFS_TITLE_FORMAT="p/d/n"																																		#
+# Automatically update grub
-#		(Custom title, shows/hides p"prefix" d"date" n"name" in the Grub menu, separator "/", custom order available)													#
+#  If you would like grub to automatically update when Snapper timeline snapshots and cleanups occur, simply install 10-update_grub.conf in the following locations:
-# * GRUB_BTRFS_LIMIT="50"																																				#
+# - /etc/systemd/system/snapper-timeline.service.d/
-#		(Limit the number of snapshots populated in the GRUB menu.)																										#
+# - /etc/systemd/system/snapper-cleanup.service.d/
-# * GRUB_BTRFS_SUBVOLUME_SORT="descending"																																#
+# Once the configuration files are in place, systemctl daemon-reload should be run to reload the units and make the changes active.
-#		(Sort the found subvolumes by newest first ("descending") or oldest first ("ascending").																		#
+#
-#		If "ascending" is chosen then the $GRUB_BTRFS_LIMIT oldest subvolumes will populate the menu.)																	#
+# Special thanks for assistance and contributions:
-# * GRUB_BTRFS_SHOW_SNAPSHOTS_FOUND="true"																																#
+# - My friends
-#		(Show snapshots found during run "grub-mkconfig")																												#
+# - All contributors on Github
-# * GRUB_BTRFS_SHOW_TOTAL_SNAPSHOTS_FOUND="true"																														#
+#
-#		(Show Total of snapshots found during run "grub-mkconfig")																										#
-# * GRUB_BTRFS_NKERNEL=("vmlinuz-linux") 		 																														#
-#		(Use only if you have custom kernel name.)			                        																					#
-# * GRUB_BTRFS_NINIT=("initramfs-linux.img" "initramfs-linux-fallback.img")																								#
-#		(Use only if you have custom initramfs name.)						                      																		#
-# * GRUB_BTRFS_INTEL_UCODE=("intel-ucode.img") 																															#
-#		(Use only if you have custom intel-ucode.)		    			                          																		#
-# * GRUB_BTRFS_IGNORE_SPECIFIC_PATH=("var/lib/docker")					             																					#
-#		(Ignore specific path during run "grub-mkconfig")																												#
-# * GRUB_BTRFS_SNAPPER_CONFIG="root"																																	#
-#		(Snapper's config name to use)																																	#
-# * GRUB_BTRFS_DISABLE="false"																																			#
-#		Disable Grub-btrfs (default=active)																																#
-#																																										#
-# - Generate grub.cfg (on Arch Linux use grub-mkconfig -o /boot/grub/grub.cfg)																							#
-#																																										#
-# - grub-btrfs automatically generates snapshots entries.																												#
-# - You will see it appear different entries (e.g : Snapshot: [2014-02-12 11:24:37] my snapshot name overkill)															#
-#																																										#
-# Automatically update grub																																				#
-#  If you would like grub to automatically update when Snapper timeline snapshots and cleanups occur, simply install 10-update_grub.conf in the following locations:	#
-# - /etc/systemd/system/snapper-timeline.service.d/																														#
-# - /etc/systemd/system/snapper-cleanup.service.d/																														#
-# Once the configuration files are in place, systemctl daemon-reload should be run to reload the units and make the changes active.										#
-#																																										#
-# Special thanks for assistance and contributions:																														#
-# - My friends																																							#
-# - All contributors on Github																																			#
-#																																										#
 #########################################################################################################################################################################
 
 set -e
@@ -72,8 +43,10 @@ prefix="/usr"
 exec_prefix="/usr"
 datarootdir="/usr/share"
 sysconfdir="/etc"
+grub_btrfs_config="${sysconfdir}/grub.d/41_snapshots-btrfs_config"
 
 . "${sysconfdir}/default/grub"
+[[ -f "$grub_btrfs_config" ]] && . "$grub_btrfs_config"
 . "$datarootdir/grub/grub-mkconfig_lib"
 
 ######################################
@@ -113,6 +86,8 @@ ignore_specific_path=("${GRUB_BTRFS_IGNORE_SPECIFIC_PATH[@]}")
 ## snapper's config name
 snapper_config=${GRUB_BTRFS_SNAPPER_CONFIG:-"root"}
 
+grub_directory=${GRUB_BTRFS_DIRNAME:-"grub"}
+
 ########################
 ### variables script ###
 ########################
@@ -135,6 +110,16 @@ gbgmp=$(mktemp -d)
 CLASS="--class snapshots --class gnu-linux --class gnu --class os"
 ## save IFS
 oldIFS=$IFS
+## Detect uuid requirement (lvm,btrfs...)
+check_uuid_required() {
+if [ "x${GRUB_DEVICE_UUID}" = "x" ] || [ "x${GRUB_DISABLE_LINUX_UUID}" = "xtrue" ] \
+    || ! test -e "/dev/disk/by-uuid/${GRUB_DEVICE_UUID}" \
+    || ( test -e "${GRUB_DEVICE}" && uses_abstraction "${GRUB_DEVICE}" lvm ); then
+  LINUX_ROOT_DEVICE=${GRUB_DEVICE}
+else
+  LINUX_ROOT_DEVICE=UUID=${GRUB_DEVICE_UUID}
+fi
+}
 
 
 ######################
@@ -164,10 +149,10 @@ test_btrfs()
 
 ## Create entry
 entry()	{
-echo "$@" >> "/boot/grub/grub-btrfs.cfg"
+echo "$@" >> "/boot/$grub_directory/grub-btrfs.cfg"
 # local arg="$@"
-# echo "${arg}" >> "/boot/grub/grub-btrfs.cfg"
+# echo "${arg}" >> "/boot/$grub_directory/grub-btrfs.cfg"
-# cat << EOF >> "/boot/grub/grub-btrfs.cfg"
+# cat << EOF >> "/boot/$grub_directory/grub-btrfs.cfg"
 # ${arg}
 # EOF
 }
@@ -212,7 +197,7 @@ make_menu_entries()
 		fi
 		echo 'Loading Snapshot: "${snap_date_time}" "${snap_dir_name}"'
 		echo 'Loading Kernel: "${k}" ...'
-		linux \"${boot_dir_root_grub}/"${k}"\" root=UUID=${root_uuid} rw rootflags=subvol=\""${snap_dir_name}"\" ${kernel_parameters}"
+		linux \"${boot_dir_root_grub}/"${k}"\" root="${LINUX_ROOT_DEVICE}" rw rootflags=subvol=\""${snap_dir_name}"\" ${kernel_parameters}"
 				if [[ -f "${boot_dir}"/"${u}" && "${i}" != "${prefix_i}-${kversion}-${alt_suffix_i}" ]] ; then
 					entry "\
 		echo 'Loading Microcode & Initramfs: "${u}" "${i}" ...'
@@ -421,7 +406,7 @@ boot_bounded()
 		snap_dir_name="$(trim "$snap_dir_name")"
 		snap_date_time="$(echo "$item" | cut -d' ' -f1-2)"
 		snap_date_time="$(trim "$snap_date_time")"
-		
+
 		boot_dir="$gbgmp/$snap_dir_name/boot"
 		# Kernel (Original + custom kernel)
 		detect_kernel
@@ -464,12 +449,12 @@ boot_separate()
 	detect_kernel
 	if [ -z "${list_kernel}" ]; then print_error "Kernels not found."; fi
 	name_kernel=("${list_kernel[@]##*"/"}")
-	
+
 	# Initramfs (Original + custom initramfs)
 	detect_initramfs
 	if [ -z "${list_initramfs}" ]; then print_error "Initramfs not found."; fi
 	name_initramfs=("${list_initramfs[@]##*"/"}")
-	
+
 	# microcode (auto-detect + custom microcode)
 	detect_microcode
 	name_microcode=("${list_ucode[@]##*"/"}")
@@ -509,8 +494,8 @@ printf "###### - Grub-btrfs: Snapshot detection started - ######\n" >&2 ;
 # if btrfs prog isn't installed, exit
 test_btrfs
 # Delete existing config
-#rm -f --preserve-root "/boot/grub/grub-btrfs.cfg"
+#rm -f --preserve-root "/boot/$grub_directory/grub-btrfs.cfg"
-> "/boot/grub/grub-btrfs.cfg"
+> "/boot/$grub_directory/grub-btrfs.cfg"
 # Create mount point then mounting
 [[ ! -d $gbgmp ]] && mkdir -p $gbgmp
 mount -o subvolid=5 /dev/disk/by-uuid/$root_uuid $gbgmp/
@@ -518,6 +503,8 @@ mount -o subvolid=5 /dev/disk/by-uuid/$root_uuid $gbgmp/
 count_warning_menuentries=0
 # Count snapshots
 count_limit_snap=0
+# detect uuid requirement
+check_uuid_required
 # Detects if /boot is a separate partition
 if [[ "$root_uuid" != "$boot_uuid" ]]; then
 	printf "# Info: Separate boot partition detected \n" >&2 ;
@@ -539,7 +526,7 @@ fi
 if [[ "${count_limit_snap}" = "0" || -z "${count_limit_snap}" ]]; then
 	print_error "No snapshots found."
 fi
-root_grub="$(make_system_path_relative_to_its_root /boot/grub)"
+root_grub="$(make_system_path_relative_to_its_root /boot/$grub_directory)"
 # Make a submenu in GRUB (grub.cfg)
 cat << EOF
 submenu '${submenuname}' {

41_snapshots-btrfs_config

@@ -0,0 +1,17 @@
+#!/usr/bin/env bash
+
+# GRUB_BTRFS_SUBMENUNAME="Arch Linux snapshots"                              # Name appearing in the Grub menu
+# GRUB_BTRFS_PREFIXENTRY="Snapshot:"                                         # Add a name ahead your snapshots entries in the Grub menu
+# GRUB_BTRFS_DISPLAY_PATH_SNAPSHOT="true"                                    # Show full path snapshot or only name in the Grub menu
+# GRUB_BTRFS_TITLE_FORMAT="p/d/n"                                            # Custom title, shows/hides p"prefix" d"date" n"name" in the Grub menu, separator "/", custom order available
+# GRUB_BTRFS_LIMIT="50"                                                      # Limit the number of snapshots populated in the GRUB menu
+# GRUB_BTRFS_SUBVOLUME_SORT="descending"                                     # Sort the found subvolumes by newest first ("descending") or oldest first ("ascending") and show $GRUB_BTRFS_LIMIT first entries.
+# GRUB_BTRFS_SHOW_SNAPSHOTS_FOUND="true"                                     # Show snapshots found during run "grub-mkconfig"
+# GRUB_BTRFS_SHOW_TOTAL_SNAPSHOTS_FOUND="true"                               # Show Total of snapshots found during run "grub-mkconfig"
+# GRUB_BTRFS_NKERNEL=("vmlinuz-linux")                                       # Use only if you have custom kernel name
+# GRUB_BTRFS_NINIT=("initramfs-linux.img" "initramfs-linux-fallback.img")    # Use only if you have custom initramfs name
+# GRUB_BTRFS_INTEL_UCODE=("intel-ucode.img")                                 # Use only if you have custom intel-ucode
+# GRUB_BTRFS_IGNORE_SPECIFIC_PATH=("var/lib/docker")                         # Ignore specific path during run "grub-mkconfig"
+# GRUB_BTRFS_SNAPPER_CONFIG="root"                                           # Snapper's config name to use
+# GRUB_BTRFS_DISABLE="false"                                                 # Disable Grub-btrfs
+# GRUB_BTRFS_DIRNAME=grub							     # Might be grub2 on some systems ex. /boot/grub2/...

README.md

@@ -86,6 +86,10 @@ Add this lines to /etc/default/grub:
 
 	(Disable grub-btrfs)
 
+* GRUB_BTRFS_DIRNAME="grub"
+
+	(Name of the grub folder on /boot/)
+
 
 Generate grub.cfg (on Arch linux use grub-mkconfig -o /boot/grub/grub.cfg )
 
@@ -100,6 +104,8 @@ If you would like grub to automatically update when Snapper timeline snapshots a
 - `/etc/systemd/system/snapper-timeline.service.d/`
 - `/etc/systemd/system/snapper-cleanup.service.d/`
 
+Or copy `grub-btrfs.path` and `grub-btrfs.service` to `/etc/systemd/system/`
+
 Once the configuration files are in place, `systemctl daemon-reload` should be run to reload the units and make the changes active.
 
 ##

grub-btrfs.path

@@ -0,0 +1,8 @@
+[Unit]
+Description=Monitors for new snapshots
+
+[Path]
+PathModified=/.snapshots
+
+[Install]
+WantedBy=multi-user.target

grub-btrfs.service

@@ -0,0 +1,10 @@
+[Unit]
+Description=Regenerate grub-btrfs.cfg
+
+[Service]
+Type=oneshot
+#Inital setup
+EnvironmentFile=/etc/grub.d/41_snapshots-btrfs_config
+ExecStartPre=-/bin/bash -c '[ ! -f "/boot/${GRUB_BTRFS_DIRNAME:-grub}/grub-btrfs.cfg" ] && grub2-mkconfig -o /boot/${GRUB_BTRFS_DIRNAME:-grub}/grub.cfg'
+#Regenerate grub-btrfs.cfg instead of the whole grub menu
+ExecStart=/etc/grub.d/41_snapshots-btrfs