dsnap-sync: introduce snapper template for dsnap-sync

Signed-off-by: Ralf Zerres <ralf.zerres@networkx.de>

etc/snapper/config-templates/dsnap-sync

@@ -0,0 +1,59 @@
+###
+# snapper template for dsnap-sync handling
+###
+
+# subvolume to snapshot
+SUBVOLUME="/var/lib/dsnap-sync"
+
+# filesystem type
+FSTYPE="btrfs"
+
+# users and groups allowed to work with config
+ALLOW_USERS=""
+ALLOW_GROUPS="adm"
+
+# sync users and groups from ALLOW_USERS and ALLOW_GROUPS to .snapshots
+# directory
+SYNC_ACL="yes"
+
+# start comparing pre- and post-snapshot in background after creating
+# post-snapshot
+BACKGROUND_COMPARISON="yes"
+
+# handele NUMBER_CLEANUP via systemd, if a timer unit is active
+NUMBER_CLEANUP="yes"
+
+# limit for number cleanup
+NUMBER_MIN_AGE="1800"
+NUMBER_LIMIT="52"
+NUMBER_LIMIT_IMPORTANT="12"
+
+# handle TIMELINE via systemd, if a timer unit is active
+TIMELINE_CREATE="no"
+
+# create a systemd.timer unit to handle TIMELINE cleanup
+TIMELINE_CLEANUP="yes"
+
+# timeline settings
+TIMELINE_MIN_AGE="1800"
+TIMELINE_LIMIT_HOURLY="1"
+TIMELINE_LIMIT_DAILY="14"
+TIMELINE_LIMIT_MONTHLY="11"
+TIMELINE_LIMIT_YEARLY="2"
+
+# cleanup empty pre-post-pairs
+EMPTY_PRE_POST_CLEANUP="yes"
+
+# limits for empty pre-post-pair cleanup
+EMPTY_PRE_POST_MIN_AGE="1800"
+
+# uncomment to exclude this subvol when calling
+# snap-sync as timer unit
+SNAP_SYNC_EXCLUDE="yes"
+
+# Valid CONFIG_TYPE: archive, child, parent
+# CONFIG_TYPE="archive" -> if synced, stream snapshot to a non btrfs filesystem
+# CONFIG_TYPE="child"   -> if synced, stream snapshot to a given CHILD_CONFIG name
+CONFIG_TYPE="child"
+#CHILD_CONFIG=<child config name>
+#PARENT_CONFIG=<parent config name>