Set umask used when executing hooks via "umask" option in borgmatic hooks section (#189).

NEWS

@@ -3,6 +3,7 @@
    customize the log level. See the documentation for more information:
    https://torsion.org/borgmatic/docs/how-to/inspect-your-backups/
  * #178: Look for .yml configuration file extension in addition to .yaml.
+ * #189: Set umask used when executing hooks via "umask" option in borgmatic hooks section.
  * Remove Python cache files before each Tox run.
  * Add #borgmatic Freenode IRC channel to documentation.
  * Add Borg/borgmatic hosting providers section to documentation.

borgmatic/commands/borgmatic.py

@@ -281,7 +281,11 @@ def run_configuration(config_filename, config, args):  # pragma: no cover
 
         if args.create:
             hook.execute_hook(
-                hooks.get('before_backup'), config_filename, 'pre-backup', args.dry_run
+                hooks.get('before_backup'),
+                hooks.get('umask'),
+                config_filename,
+                'pre-backup',
+                args.dry_run,
             )
 
         for repository_path in location['repositories']:
@@ -298,10 +302,16 @@ def run_configuration(config_filename, config, args):  # pragma: no cover
 
         if args.create:
             hook.execute_hook(
-                hooks.get('after_backup'), config_filename, 'post-backup', args.dry_run
+                hooks.get('after_backup'),
+                hooks.get('umask'),
+                config_filename,
+                'post-backup',
+                args.dry_run,
             )
     except (OSError, CalledProcessError):
-        hook.execute_hook(hooks.get('on_error'), config_filename, 'on-error', args.dry_run)
+        hook.execute_hook(
+            hooks.get('on_error'), hooks.get('umask'), config_filename, 'on-error', args.dry_run
+        )
         raise
 
 

borgmatic/config/schema.yaml

@@ -326,3 +326,7 @@ map:
                 desc: List of one or more shell commands or scripts to execute in case an exception has occurred.
                 example:
                     - echo "Error while creating a backup."
+            umask:
+                type: scalar
+                desc: Umask used when executing hooks. Defaults to the umask that borgmatic is run with.
+                example: 0077

borgmatic/hook.py

@@ -1,4 +1,5 @@
 import logging
+import os
 
 from borgmatic import execute
 from borgmatic.logger import get_logger
@@ -6,10 +7,13 @@ from borgmatic.logger import get_logger
 logger = get_logger(__name__)
 
 
-def execute_hook(commands, config_filename, description, dry_run):
+def execute_hook(commands, umask, config_filename, description, dry_run):
     '''
-    Given a list of hook commands to execute, a config filename, a hook description, and whether
-    this is a dry run, run the given commands. Or, don't run them if this is a dry run.
+    Given a list of hook commands to execute, a umask to execute with (or None), a config filename,
+    a hook description, and whether this is a dry run, run the given commands. Or, don't run them
+    if this is a dry run.
+
+    Raise ValueError if the umask cannot be parsed.
     '''
     if not commands:
         logger.debug('{}: No commands to run for {} hook'.format(config_filename, description))
@@ -28,10 +32,23 @@ def execute_hook(commands, config_filename, description, dry_run):
             )
         )
 
-    for command in commands:
-        if not dry_run:
-            execute.execute_command(
-                [command],
-                output_log_level=logging.ERROR if description == 'on-error' else logging.WARNING,
-                shell=True,
-            )
+    if umask:
+        parsed_umask = int(str(umask), 8)
+        logger.debug('{}: Set hook umask to {}'.format(config_filename, oct(parsed_umask)))
+        original_umask = os.umask(parsed_umask)
+    else:
+        original_umask = None
+
+    try:
+        for command in commands:
+            if not dry_run:
+                execute.execute_command(
+                    [command],
+                    output_log_level=logging.ERROR
+                    if description == 'on-error'
+                    else logging.WARNING,
+                    shell=True,
+                )
+    finally:
+        if original_umask:
+            os.umask(original_umask)

tests/unit/test_hook.py

@@ -10,7 +10,7 @@ def test_execute_hook_invokes_each_command():
         [':'], output_log_level=logging.WARNING, shell=True
     ).once()
 
-    module.execute_hook([':'], 'config.yaml', 'pre-backup', dry_run=False)
+    module.execute_hook([':'], None, 'config.yaml', 'pre-backup', dry_run=False)
 
 
 def test_execute_hook_with_multiple_commands_invokes_each_command():
@@ -21,17 +21,27 @@ def test_execute_hook_with_multiple_commands_invokes_each_command():
         ['true'], output_log_level=logging.WARNING, shell=True
     ).once()
 
-    module.execute_hook([':', 'true'], 'config.yaml', 'pre-backup', dry_run=False)
+    module.execute_hook([':', 'true'], None, 'config.yaml', 'pre-backup', dry_run=False)
+
+
+def test_execute_hook_with_umask_sets_that_umask():
+    flexmock(module.os).should_receive('umask').with_args(0o77).and_return(0o22).once()
+    flexmock(module.os).should_receive('umask').with_args(0o22).once()
+    flexmock(module.execute).should_receive('execute_command').with_args(
+        [':'], output_log_level=logging.WARNING, shell=True
+    )
+
+    module.execute_hook([':'], 77, 'config.yaml', 'pre-backup', dry_run=False)
 
 
 def test_execute_hook_with_dry_run_skips_commands():
     flexmock(module.execute).should_receive('execute_command').never()
 
-    module.execute_hook([':', 'true'], 'config.yaml', 'pre-backup', dry_run=True)
+    module.execute_hook([':', 'true'], None, 'config.yaml', 'pre-backup', dry_run=True)
 
 
 def test_execute_hook_with_empty_commands_does_not_raise():
-    module.execute_hook([], 'config.yaml', 'post-backup', dry_run=False)
+    module.execute_hook([], None, 'config.yaml', 'post-backup', dry_run=False)
 
 
 def test_execute_hook_on_error_logs_as_error():
@@ -39,4 +49,4 @@ def test_execute_hook_on_error_logs_as_error():
         [':'], output_log_level=logging.ERROR, shell=True
     ).once()
 
-    module.execute_hook([':'], 'config.yaml', 'on-error', dry_run=False)
+    module.execute_hook([':'], None, 'config.yaml', 'on-error', dry_run=False)