From 8c9d5d34b1fe1a4affbf54b8699bf2735fbf72b9 Mon Sep 17 00:00:00 2001
From: Alexander Barton <alex@barton.de>
Date: Tue, 19 Apr 2016 17:48:33 +0200
Subject: [PATCH] Implement job tagging

Introduce new command line option "-t TAG"/"--tags TAG" and new job
option "[default_]tags".
---
 README.md         | 14 +++++++++++++-
 bin/backup-script | 30 ++++++++++++++++++++++++++++--
 2 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index 8fcdf38..de10ad2 100644
--- a/README.md
+++ b/README.md
@@ -14,8 +14,9 @@ Usage: `backup-script [<options>] [<system> [<system> [...]]]`
 
 Options:
 
-- `-p`, `--progress`: Show progress, see rsync(1).
 - `-n`, `--dry-run`: Test run only, don't copy any data.
+- `-p`, `--progress`: Show progress, see rsync(1).
+- `-t TAG`, `--tag TAG`: Only run jobs with tag TAG (see "tags" variable below).
 
 When no *system* is given, all defined systems are backed up.
 
@@ -166,6 +167,17 @@ Supported file systems are:
 The latest snapshot is always reachable using a symlink named `latest`
 inside the system directory.
 
+### [default_]tags
+
+Comma-separated list of tags of this job. All uppercase tag names are reserved
+and become set automatically on runtime:
+
+- NONE: Jobs with no other tags at all.
+- ALL: Matches all jobs, regardless of their tags (see `-t`/`--tags` option).
+- LOCAL: All jobs running on "localhost".
+
+Default: NONE.
+
 ### [default_]job_pre_exec
 
 Optional script to execute before `rsync` starts. Default: none.
diff --git a/bin/backup-script b/bin/backup-script
index 1099f0c..4107e24 100755
--- a/bin/backup-script
+++ b/bin/backup-script
@@ -15,6 +15,7 @@ PIDFILE="/var/run/$NAME.pid"
 
 DRYRUN=0
 VERBOSE=0
+TAG=""
 
 export LC_ALL=C
 
@@ -46,12 +47,14 @@ default_local=0
 default_generations=0
 default_job_pre_exec=""
 default_job_post_exec=""
+default_tags=""
 
 Usage() {
 	echo "Usage: $NAME [<options>] [<system> [<system> [...]]]"
 	echo
-	echo "  -p, --progress    Show progress, see rsync(1)."
-	echo "  -n, --dry-run     Test run only, don't copy any data."
+	echo "  -n, --dry-run       Test run only, don't copy any data."
+	echo "  -p, --progress      Show progress, see rsync(1)."
+	echo "  -t TAG, --tag TAG   Only run jobs with tag TAG."
 	echo
 	echo "When no <system> is given, all defined systems are used."
 	echo
@@ -292,6 +295,10 @@ while [ $# -gt 0 ]; do
 	  "-p"|"--progress")
 		VERBOSE=1; shift
 		;;
+	  "-t"|"--tag")
+		shift; TAG="$1"; shift
+		[ -n "$TAG" ] || Usage
+		;;
 	  "-"*)
 		Usage
 		;;
@@ -315,6 +322,8 @@ if [ $? -ne 0 ]; then
 	exit 1
 fi
 echo "Rsync command is $rsync, protocol version $rsync_proto."
+
+[[ -n "$TAG" ]] && echo "Running jobs tagged with \"$TAG\"."
 echo
 
 trap GotSignal SIGINT
@@ -388,6 +397,7 @@ for f in $sys; do
 	generations="$default_generations"
 	job_pre_exec="$default_job_pre_exec"
 	job_post_exec="$default_job_post_exec"
+	tags="$default_tags"
 
 	# Compatibility with backup-pull(1) script: Save global values ...
 	pre_exec_saved="$pre_exec"
@@ -423,6 +433,22 @@ for f in $sys; do
 		compress=0
 	fi
 
+	# Add "NONE" tag when no tags are given in the config file:
+	[[ -z "$tags" ]] && tags="NONE"
+	# Add "auto-tags":
+	[[ "$local" -eq 1 ]] && tags="$tags,LOCAL"
+	# Check tags
+	if [[ -n "$TAG" && "$TAG" != "ALL" ]]; then
+		echo "$tags" | grep -E "(^|,)$TAG(,|$)" >/dev/null 2>&1
+		if [ $? -ne 0 ]; then
+			if [ "$DRYRUN" -ne 0 ]; then
+				echo "Tags of system \"$system\" don't match \"$TAG\": \"$tags\". Skipped."
+				echo
+			fi
+			continue
+		fi
+	fi
+
 	# Make sure "source" ends with a slash ("/")
 	case "$source" in
 	  "*/")
-- 
2.39.2