Makefile: Make sure make is invoked with appropriate permissions (#146)

* 41_snapshots: update header
  * Update "Automatically update Grub" section.
  * Update "Purpose" section.
  * Update "What this script does" section

41_snapshots-btrfs

@@ -7,16 +7,16 @@
 #
 # Purpose:
 #   Improves Grub by adding "btrfs snapshots" to the Grub menu.
-#   You can start your system on a "snapshot" from the Grub menu.
+#   You can boot your system on a "snapshot" from the Grub menu.
-#   Supports manual snapshots, snapper ...
+#   Supports manual snapshots, snapper, timeshift ...
-#   Warning : booting on read-only snapshots can be tricky
+#   Warning : booting on read-only snapshots can be tricky.
 #   (Read about it, https://github.com/Antynea/grub-btrfs#warning-booting-on-read-only-snapshots-can-be-tricky)
 #
 # What this script does:
 # - Automatically List snapshots existing on root partition (btrfs).
 # - 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/amd microcode in "/boot" directory on snapshots.
-# - Automatically Create corresponding "menuentry" in grub.cfg
+# - Automatically Create corresponding "menuentry" in grub.cfg.
 # - Automatically detect snapper and use snapper's snapshot description if available.
 # - Automatically generate grub.cfg if you use the provided systemd service.
 #
@@ -24,15 +24,11 @@
 # - Run `make install` or look into Makefile for instructions on where to put each file.
 #
 # Customization:
-#  Refer to config for the list of available options and their default values.
+#  You have the possibility to modify many parameters in /etc/default/grub-btrfs/config.
-#  Place your configurations to /etc/default/grub-btrfs/config.
 #
 # Automatically update Grub
-#  If you would like Grub to automatically update when a snapshots is made or deleted:
+#  If you would like grub-btrfs menu to automatically update when a snapshot is created or deleted:
-#  - Use systemctl start/enable grub-btrfs.path
+#  - Refer to https://github.com/Antynea/grub-btrfs#automatically-update-grub.
-#  - grub-btrfs.path automatically (re)generates grub.cfg when a modification appears in /.snapshots folder (by default).
-#  - If your snapshots aren't mounted in /.snapshots, you must modify the watch folder using systemctl edit grub-btrfs.path
-#  - See https://github.com/Antynea/grub-btrfs#automatically-update-grub
 #
 # Special thanks for assistance and contributions:
 # - My friends

Makefile

@@ -1,19 +1,25 @@
 PKGNAME ?= grub-btrfs
 PREFIX ?= /usr
 
+INITCPIO ?= false
+
 SHARE_DIR = $(DESTDIR)$(PREFIX)/share
 LIB_DIR = $(DESTDIR)$(PREFIX)/lib
 
 .PHONY: install uninstall help
 
 install:
+	@if test "$(shell id -u)" != 0; then \
+		echo "You are not root, run this target as root please."; \
+		exit 1; \
+	fi
 	@install -Dm755 -t "$(DESTDIR)/etc/grub.d/" 41_snapshots-btrfs
 	@install -Dm644 -t "$(DESTDIR)/etc/default/grub-btrfs/" config
 	@install -Dm644 -t "$(LIB_DIR)/systemd/system/" grub-btrfs.service
 	@install -Dm644 -t "$(LIB_DIR)/systemd/system/" grub-btrfs.path
 	@install -Dm644 -t "$(SHARE_DIR)/licenses/$(PKGNAME)/" LICENSE
 	@# Arch Linux like distros only :
-	@if command -V mkinitcpio >/dev/null 2>&1; then \
+	@if test "$(INITCPIO)" = true; then \
 		install -Dm644 "initramfs/Arch Linux/overlay_snap_ro-install" "$(LIB_DIR)/initcpio/install/grub-btrfs-overlayfs"; \
 		install -Dm644 "initramfs/Arch Linux/overlay_snap_ro-hook" "$(LIB_DIR)/initcpio/hooks/grub-btrfs-overlayfs"; \
 	 fi
@@ -21,6 +27,10 @@ install:
 	@install -Dm644 "initramfs/readme.md" "$(SHARE_DIR)/doc/$(PKGNAME)/initramfs-overlayfs.md"
 
 uninstall:
+	@if test "$(shell id -u)" != 0; then \
+		echo "You are not root, run this target as root please."; \
+		exit 1; \
+	fi
 	@grub_dirname="$$(grep -oP '^[[:space:]]*GRUB_BTRFS_GRUB_DIRNAME=\K.*' "$(DESTDIR)/etc/default/grub-btrfs/config" | sed "s|\s*#.*||;s|(\s*\(.\+\)\s*)|\1|;s|['\"]||g")"; \
 	 rm -f "$${grub_dirname:-/boot/grub}/grub-btrfs.cfg"
 	@rm -f "$(DESTDIR)/etc/default/grub-btrfs/config"
@@ -29,8 +39,8 @@ uninstall:
 	@rm -f "$(LIB_DIR)/systemd/system/grub-btrfs.path"
 	@rm -f "$(LIB_DIR)/initcpio/install/grub-btrfs-overlayfs"
 	@rm -f "$(LIB_DIR)/initcpio/hooks/grub-btrfs-overlayfs"
-	@# Arch Linux unlike distros only :
+	@# Arch Linux UNlike distros only :
-	@if ! command -V mkinitcpio >/dev/null 2>&1; then \
+	@if test "$(INITCPIO)" != true && test -d "$(LIB_DIR)/initcpio"; then \
 		rmdir --ignore-fail-on-non-empty "$(LIB_DIR)/initcpio/install" || :; \
 		rmdir --ignore-fail-on-non-empty "$(LIB_DIR)/initcpio/hooks" || :; \
 		rmdir --ignore-fail-on-non-empty "$(LIB_DIR)/initcpio" || :; \
@@ -50,11 +60,12 @@ help:
 	@echo "           uninstall"
 	@echo "           help"
 	@echo
-	@echo "  parameters | description                    | defaults"
+	@echo "  parameter | type | description                    | defaults"
-	@echo "  -----------+--------------------------------+----------------------------"
+	@echo "  ----------+------+--------------------------------+----------------------------"
-	@echo "  DESTDIR    | install destination            | <unset>"
+	@echo "  DESTDIR   | path | install destination            | <unset>"
-	@echo "  PREFIX     | system tree prefix             | '/usr'"
+	@echo "  PREFIX    | path | system tree prefix             | '/usr'"
-	@echo "  SHARE_DIR  | shared data location           | '\$$(DESTDIR)\$$(PREFIX)/share'"
+	@echo "  SHARE_DIR | path | shared data location           | '\$$(DESTDIR)\$$(PREFIX)/share'"
-	@echo "  LIB_DIR    | system libraries location      | '\$$(DESTDIR)\$$(PREFIX)/lib'"
+	@echo "  LIB_DIR   | path | system libraries location      | '\$$(DESTDIR)\$$(PREFIX)/lib'"
-	@echo "  PKGNAME    | name of the ditributed package | 'grub-btrfs'"
+	@echo "  PKGNAME   | name | name of the ditributed package | 'grub-btrfs'"
+	@echo "  INITCPIO  | bool | include mkinitcpio hook        | false"
 	@echo

README.md

@@ -6,10 +6,10 @@
 This is a version 4.xx of grub-btrfs
 ##### BTC donation address: `1Lbvz244WA8xbpHek9W2Y12cakM6rDe5Rt`
 ##
-### Description
+### Description :
 Improves Grub by adding "btrfs snapshots" to the Grub menu.
 
-You can start your system on a "snapshot" from the Grub menu.  
+You can boot your system on a "snapshot" from the Grub menu.  
 Supports manual snapshots, snapper, timeshift ...
 
 ##### Warning: booting on read-only snapshots can be tricky
@@ -46,29 +46,52 @@ NOTE: Generate your Grub menu after installation for the changes to take effect.
 On Arch Linux use `grub-mkconfig -o /boot/grub/grub.cfg`.
 
 ##
-### Customization:
+### Customization :
 
 You have the possibility to modify many parameters in `/etc/default/grub-btrfs/config`.  
 See [config file](https://github.com/Antynea/grub-btrfs/blob/master/config) for more information.
 
 ##
 ### Automatically update grub
-If you would like Grub to automatically update when a snapshot is made or deleted:
+1- If you would like grub-btrfs menu to automatically update when a snapshot is created or deleted:
-* Use `systemctl start/enable grub-btrfs.path`.
+* Use `systemctl enable grub-btrfs.path`.
-* `grub-btrfs.path` automatically (re)generates `grub.cfg` when a modification appears in `/.snapshots` folder (by default).
+  * `grub-btrfs.path` automatically (re)generates `grub-btrfs.cfg` when a modification appears in `/.snapshots` mount point (by default).
-* If your snapshots aren't mounted in `/.snapshots`, you must modify the watch folder using `systemctl edit grub-btrfs.path`.  
+  * If the `/.snapshots` mount point is already mounted, then use `systemctl start grub-btrfs.path` to start monitoring.  
-	* For example: Timeshift mount its snapshots in `/run/timeshift/backup/timeshift-btrfs/snapshots` folder.
+    Otherwise, the unit will automatically start monitoring when the mount point will be available.
+* If your snapshots location aren't mounted in `/.snapshots`, you must modify `grub-btrfs.path` unit using  
+`systemctl edit --full grub-btrfs.path` and run `systemctl reenable grub-btrfs.path` for changes take effect.  
+To find out the name of the `.mount` unit  
+use `systemctl list-units -t mount`.  
+	* For example: Timeshift mounts its snapshot folder in `/run/timeshift/backup/timeshift-btrfs/snapshots`.
 
-		Use `systemctl edit grub-btrfs.path`.
+		Use `systemctl edit --full grub-btrfs.path`.
-		Then wrote:
+		Then replace the whole block by:
 		```
+		[Unit]
+		Description=Monitors for new snapshots
+		DefaultDependencies=no
+		Requires=run-timeshift-backup.mount
+		After=run-timeshift-backup.mount
+		BindsTo=run-timeshift-backup.mount
+
 		[Path]
 		PathModified=/run/timeshift/backup/timeshift-btrfs/snapshots
+
+		[Install]
+		WantedBy=run-timeshift-backup.mount
 		```
-		and finally save.
+		Then save and finally run `systemctl reenable grub-btrfs.path` for changes take effect.  
+		Optional:  
+		If the `/run/timeshift/backup/timeshift-btrfs/snapshots` mount point is already mounted,  
+		then use `systemctl start grub-btrfs.path` to start monitoring.  
+		Otherwise, the unit will automatically start monitoring when the mount point will be available.  
 	* You can view your change to `systemctl cat grub-btrfs.path`.
 	* To revert change use `systemctl revert grub-btrfs.path`.
-##### Warning:
+
+2- If you would like grub-btrfs menu to automatically update on system restart/shutdown:  
+[Look at this comment](https://github.com/Antynea/grub-btrfs/issues/138#issuecomment-766918328)  
+Currently not implemented  
+##### Warning :
 by default, `grub-mkconfig` command is used.  
 Might be `grub2-mkconfig` on some systems (Fedora ...).   
 Edit `GRUB_BTRFS_MKCONFIG` variable in `/etc/default/grub-btrfs/config` file to reflect this.

grub-btrfs.path

@@ -1,8 +1,12 @@
 [Unit]
 Description=Monitors for new snapshots
+DefaultDependencies=no
+Requires=\x2esnapshots.mount
+After=\x2esnapshots.mount
+BindsTo=\x2esnapshots.mount
 
 [Path]
 PathModified=/.snapshots
 
 [Install]
-WantedBy=multi-user.target
+WantedBy=\x2esnapshots.mount