Truly support custom PREFIX= install

* Before, doing `$ PREFIX=/usr/local make install` would install files to`/usr/local/usr/local..` which is wrong
* With this PR, files will be installed to the expected location e.g. `/usr/local/etc/restic`
* `Makefile` almost completely rewritten
   * As e.g. `default.env` would source `_global.env`, `default.env` must be edited to find the right location of `_global.env` depending on what `$PREFIX` was set to.
   * see documented build stages in the `Makefile` itself.
   *  Made sure that the rules are correct so that only modifed files are installed, not all at once unnecessarily like before.
* A sub-goal was that the [PKGBUILD](https://aur.archlinux.org/cgit/aur.git/tree/PKGBUILD?h=restic-systemd-automatic-backup#n20) for Arch should not need to do any custom install configuration, to keep everything easier to maintain. `$ make install` should work out of the box for Arch.
* Additionally added the `-b` flag to `install(1)` that makes a backup of existing `etc/restic/*` files before installing a newer version.

Fixes #49

.gitignore

@@ -1,7 +1,5 @@
-# Prevent check-in of these sensitive files. Instead they are generated from the corresponding *.template file.
-etc/restic/pw.txt
-etc/restic/_global.env
-etc/restic/default.env
+# make install
+/build
 
 # IntelliJ
 .idea/

CHANGELOG.md

@@ -7,6 +7,19 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 ### Added
 - `resticw` wrapper for working with different profiles without the need to source the profiles first.
+- `$make install` will now make a timestamped backup of any existing `/etc/restic/*` files before installing a newer version.
+
+### Changed
+- **BREAKING CHANGE** moved systemd installation with makefile from `/etc/systemd/system` to `/usr/lib/systemd/system` as this is what packages should do. This is to be able to simplify the arch [PKGBUILD](https://aur.archlinux.org/cgit/aur.git/tree/PKGBUILD?h=restic-systemd-automatic-backup) so that it does not need to do anything else than `make install`.
+   - If you upgrade form an existing install, you should disable and then re-enable the timer, so that the symlink is pointing to the new location of the timer.
+   ```console
+   # systemctl disable restic-backup@<profile>.timer
+   # systemctl enable restic-backup@<profile>.timer
+   ```
+- **BREAKING CHANGE** moved script installation with makefile from `/usr/local/sbin` to `/sbin` to have a simpler interface to work with `$PREFIX`.
+
+### Fixed
+- Installation with custom `PREFIX` now works properly with Make: `$ PREFIX=/usr/local make install` whill now install everything at the expected location. With this, it's easy to use this script as non-root user on e.g. an macOS system.
 
 ## [4.0.0] - 2022-02-01
 ### Fixed
@@ -46,6 +59,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 - `restic_backup.sh` now finds `.backup_exclude` files on each backup path as intended.
+- Install executeables to `$PREFIX/sbin` instead of `$PREFIX/user/local/sbin`, so that `$ PREFIX=/usr/local make install` does what is expected.
 
 ## [1.0.1] - 2021-12-03
 ### Fixed

Makefile

@@ -1,20 +1,77 @@
-# Not file targets.
-.PHONY: help install install-scripts install-conf install-systemd uninstall
+### Notes ###
+# This build process is done in three stages:
+# 1. copy source files to the local build directory.
+# 2. replace the string "$INSTALL_PREFIX" with the value of $PREFIX
+# 3. copy files from the build directory to the target directory.
+#
+# Why this dance?
+# * To fully support that a user can install this project to a custom path e.g. $(PREFIX=/usr/local make install),
+#   we need to modify the files that refer to other files on disk. We do this by having a placeholder "$INSTALL_PREFIX"
+#   that is substituted with the value of $PREFIX when installed
+# * We don't want to modify the files that are controlled by git, thus let's copy them to a build directory and then modify.
+
+### Non-file targets ###
+.PHONY: help install install-scripts install-conf install-systemd clean uninstall
 
 ### Macros ###
-SRCS_SCRIPTS	= $(filter-out %cron_mail, $(wildcard usr/local/sbin/*))
+NOW := $(shell date +%Y-%m-%d_%H:%M:%S)
+
+# Source: https://stackoverflow.com/a/14777895/265508
+ifeq ($(OS),Windows_NT)
+    CUR_OS := Windows
+else
+    CUR_OS := $(shell uname)
+endif
+
+# GNU install and macOS install have incompatible command line arguments.
+ifeq ($(CUR_OS),Darwin)
+    BAK_SUFFIX = -B .$(NOW).bak
+else
+    BAK_SUFFIX = --suffix=.$(NOW).bak
+endif
+
+# Create parent directories of a file, if not existing.
+# Reference: https://stackoverflow.com/a/25574592/265508
+MKDIR_PARENTS=sh -c '\
+	     dir=$$(dirname $$1); \
+	     test -d $$dir || mkdir -p $$dir \
+	     ' MKDIR_PARENTS
+
+
+# Source directories.
+DIR_SCRIPTS	= sbin
+DIR_CONF	= etc/restic
+DIR_SYSTEMD	= usr/lib/systemd/system
+
+# Source files.
+SRCS_SCRIPTS	= $(filter-out %cron_mail, $(wildcard $(DIR_SCRIPTS)/*))
 # $(sort) remove duplicates that comes from running make install >1 times.
-SRCS_CONF	= $(sort $(patsubst %.template, %, $(wildcard etc/restic/*)))
-SRCS_SYSTEMD	= $(wildcard etc/systemd/system/*)
+SRCS_CONF	= $(sort $(patsubst %.template, %, $(wildcard $(DIR_CONF)/*)))
+SRCS_SYSTEMD	= $(wildcard $(DIR_SYSTEMD)/*)
 
-# To change the installation root path, set the PREFIX variable in your shell's environment, like:
-# $ PREFIX=/usr/local make install
-# $ PREFIX=/tmp/test make install
-DEST_SCRIPTS	= $(PREFIX)/usr/local/sbin
-DEST_CONF	= $(PREFIX)/etc/restic
-DEST_SYSTEMD	= $(PREFIX)/etc/systemd/system
 
-INSTALLED_FILES = $(addprefix $(PREFIX)/, $(SRCS_SCRIPTS) $(SRCS_CONF) $(SRCS_SYSTEMD))
+# Local build directory. Sources will be copied here, modified and then installed from this directory.
+BUILD_DIR := build
+BUILD_DIR_SCRIPTS	= $(BUILD_DIR)/$(DIR_SCRIPTS)
+BUILD_DIR_CONF		= $(BUILD_DIR)/$(DIR_CONF)
+BUILD_DIR_SYSTEMD	= $(BUILD_DIR)/$(DIR_SYSTEMD)
+
+# Sources copied to build directory.
+BUILD_SRCS_SCRIPTS	= $(addprefix $(BUILD_DIR)/, $(SRCS_SCRIPTS))
+BUILD_SRCS_CONF		= $(addprefix $(BUILD_DIR)/, $(SRCS_CONF))
+BUILD_SRCS_SYSTEMD	= $(addprefix $(BUILD_DIR)/, $(SRCS_SYSTEMD))
+
+# Destination directories
+DEST_DIR_SCRIPTS	= $(PREFIX)/$(DIR_SCRIPTS)
+DEST_DIR_CONF		= $(PREFIX)/$(DIR_CONF)
+DEST_DIR_SYSTEMD	= $(PREFIX)/$(DIR_SYSTEMD)
+
+# Destination files.
+DEST_SCRIPTS	= $(addprefix $(PREFIX)/, $(SRCS_SCRIPTS))
+DEST_CONF	= $(addprefix $(PREFIX)/, $(SRCS_CONF))
+DEST_SYSTEMD	= $(addprefix $(PREFIX)/, $(SRCS_SYSTEMD))
+
+INSTALLED_FILES = $(DEST_SCRIPTS) $(DEST_CONF) $(DEST_SYSTEMD)
 
 ### Targets ###
 # target: all - Default target.
@@ -24,33 +81,9 @@ all: install
 help:
 	@egrep "#\starget:" [Mm]akefile  | sed 's/\s-\s/\t\t\t/' | cut -d " " -f3- | sort -d
 
-# target: install - Install all files
-install: install-scripts install-conf install-systemd
-
-
-# target: install-scripts - Install executables.
-install-scripts:
-	install -d $(DEST_SCRIPTS)
-	install -m 0744 $(filter-out %/resticw, $(SRCS_SCRIPTS)) $(DEST_SCRIPTS)
-	install -m 0755 usr/local/sbin/resticw $(DEST_SCRIPTS)
-
-# Copy templates to new files with restricted permissions.
-# Why? Because the non-template files are git-ignored to prevent that someone who clones or forks this repo checks in their sensitive data like the B2 password!
-etc/restic/_global.env etc/restic/default.env etc/restic/pw.txt:
-	install -m 0600 $@.template $@
-
-# target: install-conf - Install restic configuration files.
-# will create these files locally only if they don't already exist
-# `|` means that dependencies are order-only, i.e. only created if they don't already exist.
-install-conf: | $(SRCS_CONF)
-	install -d $(DEST_CONF)
-	install -b -m 0600 $(SRCS_CONF) $(DEST_CONF)
-	$(RM) etc/restic/_global.env etc/restic/default.env etc/restic/pw.txt
-
-# target: install-systemd - Install systemd timer and service files.
-install-systemd:
-	install -d $(DEST_SYSTEMD)
-	install -m 0644 $(SRCS_SYSTEMD) $(DEST_SYSTEMD)
+# target: clean - Remove build files.
+clean:
+	$(RM) -r $(BUILD_DIR)
 
 # target: uninstall - Uninstall ALL files from the install targets.
 uninstall:
@@ -58,3 +91,46 @@ uninstall:
 			echo $(RM) $$file; \
 			$(RM) $$file; \
 	done
+
+# To change the installation root path, set the PREFIX variable in your shell's environment, like:
+# $ PREFIX=/usr/local make install
+# $ PREFIX=/tmp/test make install
+# target: install - Install all files
+install: install-scripts install-conf install-systemd
+
+# Install targets - add build sources to prereqa as well, so that build dir is re-created if deleted (expected behaviour).
+# target: install-scripts - Install executables.
+install-scripts: $(DEST_SCRIPTS)
+# target: install-conf - Install restic configuration files.
+install-conf: $(DEST_CONF) $(BUILD_SRCS_CONF)
+# target: install-systemd - Install systemd timer and service files.
+install-systemd: $(DEST_SYSTEMD)
+
+
+# Copies sources to build directory & replace "$INSTALL_PREFIX"
+# dir= line needs to be in the same subshell to use shared envvars. Reference: https://stackoverflow.com/a/36419671/265508
+$(BUILD_DIR)/% : %
+	${MKDIR_PARENTS} $@
+	cp $< $@
+	sed -i.bak -e "s|\$$INSTALL_PREFIX|$$PREFIX|g" $@; rm $@.bak
+
+
+# For the destination files to be built, build-files must exist.
+#$(DEST_SCRIPTS): $(BUILD_SRCS_SCRIPTS)
+#$(DEST_CONF): $(BUILD_SRCS_CONF)
+#$(DEST_SYSTEMD): $(BUILD_SRCS_SYSTEMD)
+
+# Install destination script files.
+$(DEST_DIR_SCRIPTS)/%: $(BUILD_DIR_SCRIPTS)/%
+	${MKDIR_PARENTS} $@
+	install -m 0744 $< $@
+
+# Install destination conf files. Additionally backup existing files.
+$(DEST_DIR_CONF)/%: $(BUILD_DIR_CONF)/%
+	${MKDIR_PARENTS} $@
+	install -m 0600 -b $(BAK_SUFFIX) $< $@
+
+# Install destination script files.
+$(DEST_DIR_SYSTEMD)/%: $(BUILD_DIR_SYSTEMD)/%
+	${MKDIR_PARENTS} $@
+	install -m 0644 $< $@

README.md

@@ -52,7 +52,7 @@ Nevertheless the project should work out of the box, be minimal but still open t
    * `/etc/restic/backup_exclude.txt` - List of file patterns to ignore. This will trim down your backup size and the speed of the backup a lot when done properly!
 1. Initialize remote repo as described [below](#3-initialize-remote-repo)
 1. Configure [how often](https://www.freedesktop.org/software/systemd/man/systemd.time.html#Calendar%20Events) back up should be made.
-   * Edit if needed `OnCalendar` in `/etc/systemd/system/restic-check@.timer`.
+   * Edit if needed `OnCalendar` in `/usr/lib/systemd/system/restic-check@.timer`.
 1. Enable automated backup for starting with the system (`enable` creates symlinks):
    ```console
    $ sudo systemctl start restic-backup@default.timer
@@ -91,6 +91,18 @@ $ git clone https://github.com/erikw/restic-systemd-automatic-backup.git && cd $
 $ sudo make install
 ````
 
+If you want to install everything manually, we will install files to `/etc`, `/sbin`, and not use the `$make install` command, then you need to clean up a placeholder `$INSTALL_PREFIX` in the souce files first by running:
+```console
+$ find etc sbin -type f -exec sed -i.bak -e 's|$INSTALL_PREFIX||g' {} \; -exec rm {}.bak \;
+```
+and you should now see that all files have been changed like e.g.
+```diff
+-export RESTIC_PASSWORD_FILE="$INSTALL_PREFIX/etc/restic/pw.txt"
++export RESTIC_PASSWORD_FILE="/etc/restic/pw.txt"
+```
+This prefix is there so that make users can set a different `$PREFIX` when installing like `PREFIX=/usr/local make install`. So if we don't use the makefile, we need to remove this prefix with the command above just.
+
+
 Arch Linux users can install the aur package [restic-systemd-automatic-backup](https://aur.archlinux.org/packages/restic-systemd-automatic-backup/) e.g.:
 ```console
 $ yaourt -S restic-systemd-automatic-backup
@@ -126,7 +138,7 @@ $ restic init
 ```
 
 ## 4. Script for doing the backup
-Put this file in `/usr/local/sbin`:
+Put this file in `/sbin`:
 * `restic_backup.sh`: A script that defines how to run the backup. The intention is that you should not need to edit this script yourself, but be able to control everything from the `*.env` profiles.
 
 Restic support exclude files. They list file pattern paths to exclude from you backups, files that just occupy storage space, backup-time, network and money. `restic_backup.sh` allows for a few different exclude files.
@@ -139,7 +151,7 @@ Now see if the backup itself works, by running as root
 ```console
 $ sudo -i
 $ source /etc/restic/default.env
-$ /usr/local/sbin/restic_backup.sh
+$ /sbin/restic_backup.sh
 ````
 
 ## 6. Verify the backup
@@ -159,8 +171,7 @@ $ ls /mnt/restic
 ## 7. Backup automatically; systemd service + timer
 Now we can do the modern version of a cron-job, a systemd service + timer, to run the backup every day!
 
-Put these files in `/etc/systemd/system/`:
-
+Put these files in `/etc/systemd/system` (note that the Makefile installs as package to `/usr/lib/systemd/system`)
 * `restic-backup@.service`: A service that calls the backup script with the specified profile. The profile is specified
   by the value after `@` when running it (see below).
 * `restic-backup@.timer`: A timer that starts the former backup every day (same thing about profile here).
@@ -204,7 +215,7 @@ $ journalctl -f -u restic-backup@default.service
 ## 8. Email notification on failure
 We want to be aware when the automatic backup fails, so we can fix it. Since my laptop does not run a mail server, I went for a solution to set up my laptop to be able to send emails with [postfix via my Gmail](https://easyengine.io/tutorials/linux/ubuntu-postfix-gmail-smtp/). Follow the instructions over there.
 
-Put this file in `/usr/local/sbin`:
+Put this file in `/sbin`:
 * `systemd-email`: Sends email using sendmail(1). This script also features time-out for not spamming Gmail servers and getting my account blocked.
 
 Put this files in `/etc/systemd/system/`:
@@ -216,7 +227,7 @@ As you maybe noticed already before, `restic-backup.service` is configured to st
 ## 9. Optional: automated backup checks
 Once in a while it can be good to do a health check of the remote repository, to make sure it's not getting corrupt. This can be done with `$ restic check`.
 
-There is companion scripts, service and timer (`*check*`) to restic-backup.sh that checks the restic backup for errors; look in the repo in `etc/systemd/system` and `usr/local/sbin` and copy what you need over to their corresponding locations.
+There is companion scripts, service and timer (`*check*`) to restic-backup.sh that checks the restic backup for errors; look in the repo in `usr/lib/systemd/system/` and `sbin/` and copy what you need over to their corresponding locations.
 
 ```console
 $ sudo -i
@@ -245,7 +256,7 @@ straightforward (it needs to run with sudo to read environment). Just run:
 If you want to run an all-classic cron job instead, do like this:
 
 * `etc/cron.d/restic`: Depending on your system's cron, put this in `/etc/cron.d/` or similar, or copy the contents to $(sudo crontab -e). The format of this file is tested under FreeBSD, and might need adaptions depending on your cron.
-* `usr/local/sbin/cron_mail`: A wrapper for running cron jobs, that sends output of the job as an email using the mail(1) command.
+* `sbin/cron_mail`: A wrapper for running cron jobs, that sends output of the job as an email using the mail(1) command.
 
 # Uninstall
 

etc/cron.d/restic

@@ -1,5 +1,5 @@
 SHELL=/bin/sh
-PATH=/etc:/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin/:/usr/local/sbin/
+PATH=/etc:/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin/:$INSTALL_PREFIX/sbin/
 # Order of crontab fields
 # minute        hour    mday    month   wday    command
 # Reference: https://www.freebsd.org/doc/handbook/configtuning-cron.html

etc/restic/_global.env

@@ -8,9 +8,9 @@
 
 
 # The restic repository encryption key
-export RESTIC_PASSWORD_FILE="/etc/restic/pw.txt"
+export RESTIC_PASSWORD_FILE="$INSTALL_PREFIX/etc/restic/pw.txt"
 # The global restic exclude file
-export RESTIC_BACKUP_EXCLUDE_FILE="/etc/restic/backup_exclude.txt"
+export RESTIC_BACKUP_EXCLUDE_FILE="$INSTALL_PREFIX/etc/restic/backup_exclude.txt"
 
 # Backblaze B2 credentials keyID & applicationKey pair.
 # Restic environment variables are documented at https://restic.readthedocs.io/en/latest/040_backup.html#environment-variables

etc/restic/default.env

@@ -9,7 +9,7 @@
 #  Thus you don't have to provide all the arguments like
 #  $ restic --repo ... --password-file ...
 
-source /etc/restic/_global.env
+source $INSTALL_PREFIX/etc/restic/_global.env
 
 # Below envvar will override those in _global.env
 

usr/lib/systemd/system/nm-unmetered-connection.service

@@ -3,5 +3,4 @@ Description=Check if the current NetworkManager connection is metered
 
 [Service]
 Type=oneshot
-ExecStart=/usr/local/sbin/nm-unmetered-connection.sh
-
+ExecStart=$INSTALL_PREFIX/sbin/nm-unmetered-connection.sh

usr/lib/systemd/system/restic-backup@.service

@@ -10,4 +10,4 @@ Nice=10
 Environment="HOME=/root"
 # The random sleep (in seconds) is in the case of multiple backup profiles. Many restic instances started at the same time could case high load or network bandwith usage.
 # `systemd-cat` allows showing the restic output to the systemd journal
-ExecStart=bash -c 'sleep $(shuf -i 0-300 -n 1) && source /etc/restic/%I.env && /usr/local/sbin/restic_backup.sh | systemd-cat'
+ExecStart=bash -c 'sleep $(shuf -i 0-300 -n 1) && source $INSTALL_PREFIX/etc/restic/%I.env && $INSTALL_PREFIX/sbin/restic_backup.sh | systemd-cat'

usr/lib/systemd/system/restic-check@.service

@@ -8,4 +8,4 @@ Requires=nm-unmetered-connection.service
 Type=simple
 Nice=10
 # `systemd-cat` allows showing the restic output to the systemd journal
-ExecStart=bash -c 'source /etc/restic/%I.env && /usr/local/sbin/restic_check.sh | systemd-cat'
+ExecStart=bash -c 'source $INSTALL_PREFIX/etc/restic/%I.env && $INSTALL_PREFIX/sbin/restic_check.sh | systemd-cat'

usr/lib/systemd/system/status-email-user@.service

@@ -6,6 +6,6 @@ Description=Send status email for %i to user
 
 [Service]
 Type=oneshot
-ExecStart=/usr/local/sbin/systemd-email abc@gmail.com %i
+ExecStart=$INSTALL_PREFIX/sbin/systemd-email abc@gmail.com %i
 User=root
 Group=systemd-journal