Move /sbin to /bin

As more users would have /bin than /sbin in their PATH

bin/restic_backup.sh

@@ -0,0 +1,103 @@
+#!/usr/bin/env bash
+# Make a backup with restic to Backblaze B2.
+#
+# This script is typically run (as root user) either like:
+# - from restic service/timer: $PREFIX/etc/systemd/system/restic-backup.{service,timer}
+# - from a cronjob: $PREFIX/etc/cron.d/restic
+# - manually by a user. For it to work, the environment variables must be set in the shell where this script is executed
+#   $ source $PREFIX/etc/default.env
+#   $ restic_backup.sh
+
+# Exit on error, unset var, pipe failure
+set -euo pipefail
+
+# Clean up lock if we are killed.
+# If killed by systemd, like $(systemctl stop restic), then it kills the whole cgroup and all it's subprocesses.
+# However if we kill this script ourselves, we need this trap that kills all subprocesses manually.
+exit_hook() {
+	echo "In exit_hook(), being killed" >&2
+	jobs -p | xargs kill
+	restic unlock
+}
+trap exit_hook INT TERM
+
+
+# Assert that all needed environment variables are set.
+# TODO in future if this grows, move this to a restic_lib.sh
+assert_envvars() {
+	local varnames=("$@")
+	for varname in "${varnames[@]}"; do
+		if [ -z ${!varname+x} ]; then
+			printf "%s must be set for this script to work.\n\nDid you forget to source a /etc/restic/*.env profile in the current shell before executing this script?\n" "$varname" >&2
+			exit 1
+		fi
+	done
+}
+assert_envvars \
+	B2_ACCOUNT_ID B2_ACCOUNT_KEY B2_CONNECTIONS \
+	RESTIC_BACKUP_PATHS RESTIC_BACKUP_TAG \
+	RESTIC_BACKUP_EXCLUDE_FILE RESTIC_BACKUP_EXTRA_ARGS RESTIC_PASSWORD_FILE RESTIC_REPOSITORY RESTIC_VERBOSITY_LEVEL \
+	RESTIC_RETENTION_DAYS RESTIC_RETENTION_MONTHS RESTIC_RETENTION_WEEKS RESTIC_RETENTION_YEARS
+
+
+# Convert to arrays, as arrays should be used to build command lines. See https://github.com/koalaman/shellcheck/wiki/SC2086
+IFS=':' read -ra backup_paths <<< "$RESTIC_BACKUP_PATHS"
+IFS=' ' read -ra extra_args <<< "$RESTIC_BACKUP_EXTRA_ARGS"
+
+
+# Set up exclude files: global + path-specific ones
+# NOTE that restic will fail the backup if not all listed --exclude-files exist. Thus we should only list them if they are really all available.
+##  Global backup configuration.
+exclusion_args=(--exclude-file "$RESTIC_BACKUP_EXCLUDE_FILE")
+## Self-contained backup exclusion files per backup path. E.g. having an USB disk at /mnt/media in RESTIC_BACKUP_PATHS,
+# then a file /mnt/media/.backup_exclude.txt will automatically be detected and used:
+for backup_path in "${backup_paths[@]}"; do
+	if [ -f "$backup_path/.backup_exclude.txt" ]; then
+		exclusion_args=("${exclusion_args[@]}" --exclude-file "$backup_path/.backup_exclude.txt")
+	fi
+done
+
+# NOTE start all commands in background and wait for them to finish.
+# Reason: bash ignores any signals while child process is executing and thus the trap exit hook is not triggered.
+# However if put in subprocesses, wait(1) waits until the process finishes OR signal is received.
+# Reference: https://unix.stackexchange.com/questions/146756/forward-sigterm-to-child-in-bash
+
+# Remove locks from other stale processes to keep the automated backup running.
+restic unlock &
+wait $!
+
+# Do the backup!
+# See restic-backup(1) or http://restic.readthedocs.io/en/latest/040_backup.html
+# --one-file-system makes sure we only backup exactly those mounted file systems specified in $RESTIC_BACKUP_PATHS, and thus not directories like /dev, /sys etc.
+# --tag lets us reference these backups later when doing restic-forget.
+restic backup \
+	--verbose="$RESTIC_VERBOSITY_LEVEL" \
+	--one-file-system \
+	--tag "$RESTIC_BACKUP_TAG" \
+	--option b2.connections="$B2_CONNECTIONS" \
+	"${exclusion_args[@]}" \
+	"${extra_args[@]}" \
+	"${backup_paths[@]}" &
+wait $!
+
+# Dereference and delete/prune old backups.
+# See restic-forget(1) or http://restic.readthedocs.io/en/latest/060_forget.html
+# --group-by only the tag and path, and not by hostname. This is because I create a B2 Bucket per host, and if this hostname accidentially change some time, there would now be multiple backup sets.
+restic forget \
+	--verbose="$RESTIC_VERBOSITY_LEVEL" \
+	--tag "$RESTIC_BACKUP_TAG" \
+	--option b2.connections="$B2_CONNECTIONS" \
+	--prune \
+	--group-by "paths,tags" \
+	--keep-daily "$RESTIC_RETENTION_DAYS" \
+	--keep-weekly "$RESTIC_RETENTION_WEEKS" \
+	--keep-monthly "$RESTIC_RETENTION_MONTHS" \
+	--keep-yearly "$RESTIC_RETENTION_YEARS" &
+wait $!
+
+# Check repository for errors.
+# NOTE this takes much time (and data transfer from remote repo?), do this in a separate systemd.timer which is run less often.
+#restic check &
+#wait $!
+
+echo "Backup & cleaning is done."