Catch and log errors in the CLI.

backuppy/__init__.py

@@ -17,7 +17,8 @@ def assert_path(test, source_path, target_path):
                     with open(os.path.join(target_dir_path, child_file_name)) as target_f:
                         assert_file(test, source_f, target_f)
     except Exception:
-        raise AssertionError('The paths `%` and `%s` and their contents are not equal.')
+        raise AssertionError(
+            'The paths `%` and `%s` and their contents are not equal.')
 
 
 def assert_file(test, source_f, target_f):

backuppy/cli.py

@@ -4,11 +4,13 @@
 import argparse
 import json
 import re
+from logging import Handler, WARNING
 
 import yaml
 
+from backuppy import task
 from backuppy.config import from_json, from_yaml
-from backuppy.task import backup
+from backuppy.notifier import StdioNotifier
 
 FORMAT_JSON_EXTENSIONS = ('json',)
 FORMAT_YAML_EXTENSIONS = ('yml', 'yaml')
@@ -26,22 +28,41 @@ def _input(prompt=None):
         return input(prompt)
 
 
+class StdioNotifierLoggingHandler(Handler):
+    """Log warnings and more severe records to stdio."""
+
+    def __init__(self):
+        """Initialize a new instance."""
+        Handler.__init__(self, WARNING)
+        self._notifier = StdioNotifier()
+
+    def emit(self, record):
+        """Log a record.
+
+        :param record: logging.LogRecord
+        """
+        self._notifier.alert(self.format(record))
+
+
 class ConfigurationAction(argparse.Action):
     """Provide a Semantic Version action."""
 
     def __init__(self, *args, **kwargs):
         """Initialize a new instance."""
-        argparse.Action.__init__(self, *args, required=True, help='The path to the back-up configuration file.',
-                                 **kwargs)
+        kwargs.setdefault('required', True)
+        kwargs.setdefault(
+            'help', 'The path to the back-up configuration file.')
+        argparse.Action.__init__(self, *args, **kwargs)
 
     def __call__(self, parser, namespace, values, option_string=None):
         """Invoke the action."""
+        configuration_file_path = values
+
         verbose = None
         if namespace.quiet:
             verbose = False
         if namespace.verbose:
             verbose = True
-        configuration_file_path = values
         with open(configuration_file_path) as f:
             if any(map(f.name.endswith, FORMAT_JSON_EXTENSIONS)):
                 configuration_factory = from_json
@@ -52,10 +73,20 @@ def __call__(self, parser, namespace, values, option_string=None):
                     'Configuration files must have *.json, *.yml, or *.yaml extensions.')
             configuration = configuration_factory(f, verbose=verbose)
 
+            # Ensure at least some form of error logging is enabled.
+            logger = configuration.logger
+            logger.disabled = False
+            if logger.getEffectiveLevel() > WARNING:
+                logger.setLevel(WARNING)
+            if not logger.handlers:
+                configuration.notifier.inform(
+                    'The configuration does not specify any logging handlers for "backuppy", so all log records about problems will be displayed here.')
+                logger.addHandler(StdioNotifierLoggingHandler())
+
             setattr(namespace, self.dest, configuration)
 
 
-def add_configuration_to_args(parser):
+def add_configuration_to_parser(parser):
     """Add configuration options to a parser.
 
     :param parser: argparse.ArgumentParser
@@ -80,6 +111,43 @@ def add_verbose_to_args(parser):
     return parser
 
 
+def add_backup_command_to_parser(parser):
+    """Add the back-up command to a parser.
+
+    :param parser: argparse.ArgumentParser
+    :return: argparse.ArgumentParser
+    """
+    backup_parser = parser.add_parser('backup', help='Starts a back-up.')
+    backup_parser.set_defaults(
+        func=lambda parsed_args: task.backup(parsed_args.configuration))
+    add_configuration_to_parser(backup_parser)
+    return parser
+
+
+def add_init_command_to_parser(parser):
+    """Add the configuration initialization command to a parser.
+
+    :param parser: argparse.ArgumentParser
+    :return: argparse.ArgumentParser
+    """
+    init_parser = parser.add_parser(
+        'init', help='Initializes a new back-up configuration.')
+    init_parser.set_defaults(func=lambda parsed_args: init())
+    return parser
+
+
+def add_commands_to_parser(parser):
+    """Add Backuppy commands to a parser.
+
+    :param parser: argparse.ArgumentParser
+    :return: argparse.ArgumentParser
+    """
+    subparsers = parser.add_subparsers()
+    add_backup_command_to_parser(subparsers)
+    add_init_command_to_parser(subparsers)
+    return parser
+
+
 def ask_confirm(value_label, question=None, default=None):
     """Ask for a confirmation.
 
@@ -98,7 +166,8 @@ def ask_confirm(value_label, question=None, default=None):
     while confirmation is None:
         if question is not None:
             print(question)
-        confirmation_input = _input('%s %s: ' % (value_label, options_label)).lower()
+        confirmation_input = _input('%s %s: ' % (
+            value_label, options_label)).lower()
         if 'y' == confirmation_input:
             confirmation = True
         elif 'n' == confirmation_input:
@@ -146,7 +215,8 @@ def ask_option(value_label, options, question=None):
 
     option = None
     options_labels = []
-    indexed_options = [(index, value, label) for index, (value, label) in enumerate(options)]
+    indexed_options = [(index, value, label)
+                       for index, (value, label) in enumerate(options)]
     for index, _, option_label in indexed_options:
         options_labels.append('%d) %s' % (index, option_label))
     options_label = '0-%d' % (len(options) - 1)
@@ -175,8 +245,10 @@ def init():
                    required=False)
     verbose = ask_confirm(
         'Verbose output', question='Do you want back-ups to output verbose notifications?', default=True)
-    source_path = ask_any('Source path', question='What is the path to the directory you want to back up?')
-    target_path = ask_any('Target path', question='What is the path to the directory you want to back up your data to?')
+    source_path = ask_any(
+        'Source path', question='What is the path to the directory you want to back up?')
+    target_path = ask_any(
+        'Target path', question='What is the path to the directory you want to back up your data to?')
     format_options = [
         ('yaml', 'YAML (https://en.wikipedia.org/wiki/YAML)'),
         ('json', 'JSON (https://en.wikipedia.org/wiki/JSON)'),
@@ -214,11 +286,13 @@ def init():
     else:
         file_path_extensions = FORMAT_YAML_EXTENSIONS
         formatter = yaml.dump
-    file_path_extensions_label = ', '.join(map(lambda x: '*.' + x, file_path_extensions))
+    file_path_extensions_label = ', '.join(
+        map(lambda x: '*.' + x, file_path_extensions))
 
     def _file_path_validator(path):
         if not any(map(path.endswith, file_path_extensions)):
-            raise ValueError('Configuration files must have %s extensions.' % file_path_extensions_label)
+            raise ValueError(
+                'Configuration files must have %s extensions.' % file_path_extensions_label)
         return path
 
     saved = False
@@ -239,20 +313,19 @@ def main(args):
     """Provide the CLI entry point."""
     parser = argparse.ArgumentParser(
         description='Backuppy backs up and restores your data using rsync.')
-
-    subparsers = parser.add_subparsers()
-
-    backup_parser = subparsers.add_parser('backup', help='Starts a back-up.')
-    backup_parser.set_defaults(func=lambda subparser_cli_args: backup(
-        subparser_cli_args['configuration']))
-    add_configuration_to_args(backup_parser)
-
-    init_parser = subparsers.add_parser(
-        'init', help='Initializes a new back-up configuration.')
-    init_parser.set_defaults(func=lambda subparser_cli_args: init())
+    add_commands_to_parser(parser)
 
     if args:
-        cli_args = parser.parse_args(args)
-        cli_args.func(vars(cli_args))
+        parsed_args = parser.parse_args(args)
+        try:
+            parsed_args.func(parsed_args)
+        except KeyboardInterrupt:
+            # Quit gracefully.
+            print('Quitting...')
+        except BaseException:
+            configuration = parsed_args.configuration
+            configuration.logger.exception('A fatal error occurred.')
+            configuration.notifier.alert(
+                'A fatal error occurred. Details have been logged as per your configuration.')
     else:
         parser.print_help()

backuppy/config.py

@@ -1,7 +1,8 @@
 """Provides configuration components."""
 import json
+import logging
 import os
-from logging import getLogger, config as logging_config
+from logging import config as logging_config
 
 import yaml
 
@@ -27,7 +28,7 @@ def __init__(self, name, working_directory=None, verbose=False):
         self._source = None
         self._target = None
         self._notifier = None
-        self._logger = getLogger('backuppy')
+        self._logger = logging.getLogger('backuppy')
 
     @property
     def verbose(self):
@@ -165,7 +166,8 @@ def from_configuration_data(configuration_file_path, data, verbose=None):
             if 'type' not in notifier_data:
                 raise ValueError('`notifiers[][type]` is required.')
             notifier_configuration = notifier_data['configuration'] if 'configuration' in notifier_data else None
-            notifier.notifiers.append(new_notifier(configuration, notifier_data['type'], notifier_configuration))
+            notifier.notifiers.append(new_notifier(
+                configuration, notifier_data['type'], notifier_configuration))
     if not configuration.verbose:
         notifier = QuietNotifier(notifier)
     configuration.notifier = notifier
@@ -175,14 +177,16 @@ def from_configuration_data(configuration_file_path, data, verbose=None):
     if 'type' not in data['source']:
         raise ValueError('`source[type]` is required.')
     source_configuration = data['source']['configuration'] if 'configuration' in data['source'] else None
-    configuration.source = new_source(configuration, data['source']['type'], source_configuration)
+    configuration.source = new_source(
+        configuration, data['source']['type'], source_configuration)
 
     if 'target' not in data:
         raise ValueError('`target` is required.')
     if 'type' not in data['target']:
         raise ValueError('`target[type]` is required.')
     target_configuration = data['target']['configuration'] if 'configuration' in data['target'] else None
-    configuration.target = new_target(configuration, data['target']['type'], target_configuration)
+    configuration.target = new_target(
+        configuration, data['target']['type'], target_configuration)
 
     return configuration
 

backuppy/location.py

@@ -27,7 +27,8 @@ def _new_snapshot_args(name):
     return [
         # If the given snapshot does not exist, prepopulate the new snapshot with an archived, linked, recursive copy of
         # the previous snapshot if it exists, or create a new, empty snapshot otherwise.
-        ['bash', '-c', '[ ! -d %s ] && [ -d latest ] && cp -al `readlink latest` %s' % (name, name)],
+        ['bash', '-c', '[ ! -d %s ] && [ -d latest ] && cp -al `readlink latest` %s' %
+            (name, name)],
 
         # Create the new snapshot directory if it does not exist.
         ['bash', '-c', '[ ! -d %s ] && mkdir %s' % (name, name)],
@@ -166,7 +167,8 @@ def is_available(self):
             self._connect()
             return True
         except SSHException:
-            self._notifier.alert('Could not establish an SSH connection to the remote.')
+            self._notifier.alert(
+                'Could not establish an SSH connection to the remote.')
             return False
         except socket.timeout:
             self._notifier.alert('The remote timed out.')

backuppy/notifier.py

@@ -104,7 +104,8 @@ def __init__(self, state_args=None, inform_args=None, confirm_args=None, alert_a
         :param fallback_args: Optional[Iterable[str]]
         """
         if None in [state_args, inform_args, confirm_args, alert_args] and fallback_args is None:
-            raise ValueError('fallback_args must be given if one or more of the other arguments are omitted.')
+            raise ValueError(
+                'fallback_args must be given if one or more of the other arguments are omitted.')
         self._state_args = state_args
         self._inform_args = inform_args
         self._confirm_args = confirm_args
@@ -177,7 +178,8 @@ def __init__(self, state_file=None, inform_file=None, confirm_file=None, alert_f
         :param fallback_file: Optional[Iterable[str]]
         """
         if None in [state_file, inform_file, confirm_file, alert_file] and fallback_file is None:
-            raise ValueError('fallback_file must be given if one or more of the other arguments are omitted.')
+            raise ValueError(
+                'fallback_file must be given if one or more of the other arguments are omitted.')
         self._state_file = state_file
         self._inform_file = inform_file
         self._confirm_file = confirm_file
@@ -224,7 +226,8 @@ class StdioNotifier(Notifier):
     def _print(self, message, color, file=None):
         if file is None:
             file = sys.stdout
-        print('\033[0;%dm  \033[0;1;%dm %s\033[0m' % (color + 40, color + 30, message), file=file)
+        print('\033[0;%dm  \033[0;1;%dm %s\033[0m' %
+              (color + 40, color + 30, message), file=file)
 
     def state(self, message):
         """Send a notification that may be ignored.

backuppy/plugin.py

@@ -70,7 +70,8 @@ def _new_ssh_target_from_configuration_data(configuration, configuration_data):
 
     if 'port' in configuration_data:
         if configuration_data['port'] < 0 or configuration_data['port'] > 65535:
-            raise ValueError('`port` must be an integer ranging from 0 to 65535.')
+            raise ValueError(
+                '`port` must be an integer ranging from 0 to 65535.')
         kwargs['port'] = configuration_data['port']
 
     return SshTarget(configuration.notifier, **kwargs)
@@ -122,7 +123,8 @@ def _new_command_notifier_from_configuration_data(configuration, configuration_d
     alert_args = configuration_data['alert'] if 'alert' in configuration_data else None
     fallback_args = configuration_data['fallback'] if 'fallback' in configuration_data else None
     if None in [state_args, inform_args, confirm_args, alert_args] and fallback_args is None:
-        raise ValueError('`fallback` must be given if one or more of the other arguments are omitted.')
+        raise ValueError(
+            '`fallback` must be given if one or more of the other arguments are omitted.')
 
     return CommandNotifier(state_args, inform_args, confirm_args, alert_args, fallback_args)
 
@@ -135,13 +137,19 @@ def _new_file_notifier_from_configuration_data(configuration, configuration_data
     :return: CommandNotifier
     :raise: ValueError
     """
-    state_file = open(configuration_data['state'], mode='a+t') if 'state' in configuration_data else None
-    inform_file = open(configuration_data['inform'], mode='a+t') if 'inform' in configuration_data else None
-    confirm_file = open(configuration_data['confirm'], mode='a+t') if 'confirm' in configuration_data else None
-    alert_file = open(configuration_data['alert'], mode='a+t') if 'alert' in configuration_data else None
-    fallback_file = open(configuration_data['fallback'], mode='a+t') if 'fallback' in configuration_data else None
+    state_file = open(
+        configuration_data['state'], mode='a+t') if 'state' in configuration_data else None
+    inform_file = open(
+        configuration_data['inform'], mode='a+t') if 'inform' in configuration_data else None
+    confirm_file = open(
+        configuration_data['confirm'], mode='a+t') if 'confirm' in configuration_data else None
+    alert_file = open(
+        configuration_data['alert'], mode='a+t') if 'alert' in configuration_data else None
+    fallback_file = open(
+        configuration_data['fallback'], mode='a+t') if 'fallback' in configuration_data else None
     if None in [state_file, inform_file, confirm_file, alert_file] and fallback_file is None:
-        raise ValueError('`fallback` must be given if one or more of the other arguments are omitted.')
+        raise ValueError(
+            '`fallback` must be given if one or more of the other arguments are omitted.')
 
     return FileNotifier(state_file, inform_file, confirm_file, alert_file, fallback_file)
 

backuppy/task.py

@@ -30,7 +30,8 @@ def backup(configuration):
     snapshot_name = new_snapshot_name()
     target.snapshot(snapshot_name)
 
-    args = ['rsync', '-ar', '--numeric-ids', '-e', 'ssh -o "StrictHostKeyChecking no"']
+    args = ['rsync', '-ar', '--numeric-ids',
+            '-e', 'ssh -o "StrictHostKeyChecking no"']
     if configuration.verbose:
         args.append('--verbose')
         args.append('--progress')

backuppy/tests/__init__.py

@@ -1,3 +1,4 @@
 import os
 
-CONFIGURATION_PATH = '/'.join((os.path.dirname(os.path.abspath(__file__)), 'resources', 'configuration'))
+CONFIGURATION_PATH = '/'.join(
+    (os.path.dirname(os.path.abspath(__file__)), 'resources', 'configuration'))