From 8de34c192c04ce7325b3c151ef6e87642500c807 Mon Sep 17 00:00:00 2001
From: Florian Pritz <bluewind@xinu.at>
Date: Mon, 20 Feb 2017 16:01:54 +0100
Subject: backup.sh: Add configuration file support

Signed-off-by: Florian Pritz <bluewind@xinu.at>
---
 backup.sh | 81 +++++++++++++++++++++++++++++++++++++++++----------------------
 1 file changed, 53 insertions(+), 28 deletions(-)

diff --git a/backup.sh b/backup.sh
index e64c9bd..d0d1274 100755
--- a/backup.sh
+++ b/backup.sh
@@ -5,7 +5,8 @@
 #
 # Important steps:
 #  - define a host "backup" in root's .ssh/config
-#  - read the script and adjust to your needs
+#  - You can override variables from main() as well as the pre_backup() and post_backup() functions in
+#    $XDG_CONFIG_HOME/backup-sh-conf.sh or /etc/backup-sh-conf.sh
 #  - As root run `borg init -v --encryption=keyfile backup:borg-$HOSTNAME`
 #    (note that zsh uses $HOST instead of $HOSTNAME)
 #  - If you want, increase the max_segment_size in
@@ -38,38 +39,52 @@ main() {
 	TMPDIR="$(mktemp -d "/tmp/${0##*/}.XXXXXX")"
 	trap "rm -rf '${TMPDIR}'" EXIT TERM
 
-	# these mountpoints will be excluded. mountpoints not listed in either this
+	# The backup repository used by borg
+	borg_repo="backup:borg-$HOSTNAME"
+
+	# These mountpoints will be excluded. Mountpoints not listed in either this
 	# or the includeMountpoints variable below will throw an error
 	excludeMountpoints=(
-	/tmp
-	/sys
-	/dev
-	/proc
-	/run
-	/mnt/levant/nfs
-	/media
+		/tmp
+		/sys
+		/dev
+		/proc
+		/run
+		/media
 	)
 
-	# these mountpoints will be included
+	# These mountpoints will be included
 	includeMountpoints=(
-	/
-	/boot
-	/home
-	/mnt/data
+		/
+		/boot
+		/home
+		/mnt/data
 	)
 
-	# list of patterns that should be excluded. This supports shell globbing as
+	# List of patterns that should be excluded. This supports shell globbing as
 	# well as regex pattern. Refer to man borg for details.
-	IFS='' read -r -d '' excludeList_borg <<EOF || true
-sh:/home/flo/tmp/*
-sh:/home/*/.cache/*
-sh:/root/.cache/*
-sh:/var/cache/pacman/pkg/*
-EOF
+	IFS='' read -r -d '' excludeList <<-EOF || true
+		sh:/home/*/.cache/*
+		sh:/root/.cache/*
+		sh:/var/cache/pacman/pkg/*
+	EOF
+
+	for configfile in "${XDG_CONFIG_HOME:-$HOME/.config}/backup-sh-conf.sh" /etc/backup-sh-conf.sh; do
+		if [[ -e "$configfile" ]]; then
+			source "$configfile"
+		fi
+	done
 
 	exclude_mountpoints
-	echo "$excludeList_borg" > "$TMPDIR/exclude-list-borg"
+	echo "$excludeList" > "$TMPDIR/exclude-list-borg"
 
+	run_if_exists pre_backup
+	backup_borg / "$borg_repo"
+	run_if_exists post_backup
+}
+
+# This is called before creating the backup
+pre_backup() {
 	# save some data that's useful for restores
 	local backupDataDir=/root/backup-data/
 	mkdir -p "$backupDataDir"
@@ -80,12 +95,16 @@ EOF
 	df -a > "$backupDataDir/df"
 	findmnt -l > "$backupDataDir/findmnt"
 
-	# TODO: create snapshots here if possible. Sadly that's really difficult so
-	# it will probably not be implemented
+	# If you wish to use snapshots, create them here
 
-	local backupdir="borg-$HOSTNAME"
-	backup_borg / "backup:$backupdir"
-	ssh backup "touch $backupdir/last-backup-timestamp"
+	return
+}
+
+# This is called after backup creation
+post_backup() {
+	# If you need to perform any cleanup do so here
+
+	return
 }
 
 backup_borg() {
@@ -108,6 +127,12 @@ backup_borg() {
 
 ### support functions below ###
 
+run_if_exists() {
+	if declare -F $1 &> /dev/null; then
+		$1 "${@:2}"
+	fi
+}
+
 ##
 #  usage : in_array( $needle, $haystack )
 # return : 0 - found
@@ -136,7 +161,7 @@ exclude_mountpoints() {
 	local error=0
 
 	for fs in "${excludeMountpoints[@]}"; do
-		excludeList_borg+="sh:$fs/*"$'\n'
+		excludeList+="sh:$fs/*"$'\n'
 	done
 
 	while read line; do
-- 
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