Add option "--rsync-option"

README.rst

@@ -187,6 +187,7 @@ The backup process consists of several steps:
    ``--disable-notifications``,"By default a desktop notification is shown (using notify-send) before the
    system backup starts and after the backup finishes. The use of this option
    disables the notifications (notify-send will not be called at all)."
+   "``--rsync-option``, "Pass additional rsync option directly to rsync."
    "``-v``, ``--verbose``",Make more noise (increase logging verbosity). Can be repeated.
    "``-q``, ``--quiet``",Make less noise (decrease logging verbosity). Can be repeated.
    "``-h``, ``--help``",Show this message and exit.

rsync_system_backup/__init__.py

@@ -201,6 +201,13 @@ def exclude_list(self):
         """
         return []
 
+    @lazy_property(writable=True)
+    def rsync_option(self):
+        """Pass an option directly to rsync (a string or :data:`None`)."""
+        return []
+        #return value
+        #return self.rsync_option
+
     @lazy_property(writable=True)
     def excluded_roots(self):
         """
@@ -539,6 +546,9 @@ def transfer_changes(self):
             rsync_command.append('--hard-links')
             rsync_command.append('--numeric-ids')
             rsync_command.append('--xattrs')
+            # Append additional rsync option
+            for pattern in self.rsync_option:
+                rsync_command.append('%s' % pattern)
             # The following rsync option avoids including mounted external
             # drives like USB sticks in system backups.
             if not self.multi_fs:

rsync_system_backup/cli.py

@@ -150,6 +150,10 @@
     system backup starts and after the backup finishes. The use of this option
     disables the notifications (notify-send will not be called at all).
 
+  --rsync-option
+
+    Pass down additional options directly to rsync.
+
   -v, --verbose
 
     Make more noise (increase logging verbosity). Can be repeated.
@@ -203,7 +207,7 @@ def main():
     try:
         options, arguments = getopt.gnu_getopt(sys.argv[1:], 'bsrm:c:t:i:unx:fvqh', [
             'backup', 'snapshot', 'rotate', 'mount=', 'crypto=', 'tunnel=',
-            'ionice=', 'no-sudo', 'dry-run', 'multi-fs', 'exclude=', 'force',
+            'ionice=', 'no-sudo', 'dry-run', 'multi-fs', 'rsync-option=', 'exclude=', 'force',
             'disable-notifications', 'verbose', 'quiet', 'help',
         ])
         for option, value in options:
@@ -246,6 +250,9 @@ def main():
                 program_opts['exclude_list'].append(value)
             elif option == '--multi-fs':
                 program_opts['multi_fs'] = True
+            elif option == '--rsync-option':
+                program_opts.setdefault('rsync_option', [])
+                program_opts['rsync_option'].append(value)
             elif option == '--disable-notifications':
                 program_opts['notifications_enabled'] = False
             elif option in ('-v', '--verbose'):