Document validate-borgmatic-config and add a few tests.

Useful when generating the borgmatic configuration file with
configuration management and before moving the generated file in place
checking if it is actually valid.

.drone.yml

@@ -11,7 +11,7 @@ pipeline:
 matrix:
   ALPINE_VERSION:
     - 3.7
-    - 3.8
+    - 3.9
   PYTHON_VERSION:
     - 3.5
     - 3.6

AUTHORS

@@ -7,6 +7,6 @@ Johannes Feichtner: Support for user hooks
 Michele Lazzeri: Custom archive names
 Nick Whyte: Support prefix filtering for archive consistency checks
 newtonne: Read encryption password from external file
-Robin `ypid` Schneider: Support additional options of Borg
+Robin `ypid` Schneider: Support additional options of Borg and add validate-borgmatic-config command
 Scott Squires: Custom archive names
 Thomas LÉVEIL: Support for a keep_minutely prune option. Support for the --json option

NEWS

@@ -1,3 +1,7 @@
+1.3.3
+ * Add validate-borgmatic-config command, useful for validating borgmatic config generated by
+   configuration management or even edited by hand.
+
 1.3.2
  * #160: Fix for hooks executing when using --dry-run. Now hooks are skipped during a dry run.
 

borgmatic/commands/validate_config.py

@@ -0,0 +1,56 @@
+from argparse import ArgumentParser
+import sys
+import logging
+
+from borgmatic.config import collect, validate
+
+logger = logging.getLogger(__name__)
+
+
+def parse_arguments(*arguments):
+    '''
+    Given command-line arguments with which this script was invoked, parse the arguments and return
+    them as an ArgumentParser instance.
+    '''
+    config_paths = collect.get_default_config_paths()
+
+    parser = ArgumentParser(description='Validate borgmatic configuration file(s).')
+    parser.add_argument(
+        '-c',
+        '--config',
+        nargs='+',
+        dest='config_paths',
+        default=config_paths,
+        help='Configuration filenames or directories, defaults to: {}'.format(
+            ' '.join(config_paths)
+        ),
+    )
+
+    return parser.parse_args(arguments)
+
+
+def main():  # pragma: no cover
+    args = parse_arguments(*sys.argv[1:])
+
+    logging.basicConfig(level=logging.INFO, format='%(message)s')
+
+    config_filenames = tuple(collect.collect_config_filenames(args.config_paths))
+    if len(config_filenames) == 0:
+        logger.critical('No files to validate found')
+        sys.exit(1)
+
+    found_issues = False
+    for config_filename in config_filenames:
+        try:
+            validate.parse_configuration(config_filename, validate.schema_filename())
+        except (ValueError, OSError, validate.Validation_error) as error:
+            logging.critical('{}: Error parsing configuration file'.format(config_filename))
+            logging.critical(error)
+            found_issues = True
+
+    if found_issues:
+        sys.exit(1)
+    else:
+        logger.info(
+            'All given configuration files are valid: {}'.format(', '.join(config_filenames))
+        )

docs/how-to/set-up-backups.md

@@ -76,7 +76,21 @@ FAQ](http://borgbackup.readthedocs.io/en/stable/faq.html#how-can-i-specify-the-e
 for more info.
 
 
-###
+### Validation
+
+If you'd like to validate that your borgmatic configuration is valid, the
+following command is available for that:
+
+```bash
+sudo validate-borgmatic-config
+```
+
+This command's exit status (`$?` in Bash) is zero when configuration is valid
+and non-zero otherwise.
+
+Validating configuration can be useful if you generate your configuration
+files via configuration management, or you just want to double check that your
+hand edits are valid.
 
 
 ## Initialization

setup.py

@@ -1,7 +1,7 @@
 from setuptools import setup, find_packages
 
 
-VERSION = '1.3.2'
+VERSION = '1.3.3'
 
 
 setup(
@@ -26,6 +26,7 @@ setup(
             'borgmatic = borgmatic.commands.borgmatic:main',
             'upgrade-borgmatic-config = borgmatic.commands.convert_config:main',
             'generate-borgmatic-config = borgmatic.commands.generate_config:main',
+            'validate-borgmatic-config = borgmatic.commands.validate_config:main',
         ]
     },
     obsoletes=['atticmatic'],

tests/end-to-end/test_validate_config.py

@@ -0,0 +1,36 @@
+import os
+import subprocess
+import tempfile
+
+
+def test_validate_config_command_with_valid_configuration_succeeds():
+    with tempfile.TemporaryDirectory() as temporary_directory:
+        config_path = os.path.join(temporary_directory, 'test.yaml')
+
+        subprocess.check_call(
+            'generate-borgmatic-config --destination {}'.format(config_path).split(' ')
+        )
+        exit_code = subprocess.call(
+            'validate-borgmatic-config --config {}'.format(config_path).split(' ')
+        )
+
+        assert exit_code == 0
+
+
+def test_validate_config_command_with_invalid_configuration_fails():
+    with tempfile.TemporaryDirectory() as temporary_directory:
+        config_path = os.path.join(temporary_directory, 'test.yaml')
+
+        subprocess.check_call(
+            'generate-borgmatic-config --destination {}'.format(config_path).split(' ')
+        )
+        config = open(config_path).read().replace('keep_daily: 7', 'keep_daily: "7"')
+        config_file = open(config_path, 'w')
+        config_file.write(config)
+        config_file.close()
+
+        exit_code = subprocess.call(
+            'validate-borgmatic-config --config {}'.format(config_path).split(' ')
+        )
+
+        assert exit_code == 1

tests/integration/commands/test_validate_config.py

@@ -0,0 +1,20 @@
+from flexmock import flexmock
+
+from borgmatic.commands import validate_config as module
+
+
+def test_parse_arguments_with_no_arguments_uses_defaults():
+    config_paths = ['default']
+    flexmock(module.collect).should_receive('get_default_config_paths').and_return(config_paths)
+
+    parser = module.parse_arguments()
+
+    assert parser.config_paths == config_paths
+
+
+def test_parse_arguments_with_multiple_config_paths_parses_as_list():
+    flexmock(module.collect).should_receive('get_default_config_paths').and_return(['default'])
+
+    parser = module.parse_arguments('--config', 'myconfig', 'otherconfig')
+
+    assert parser.config_paths == ['myconfig', 'otherconfig']