Add "borgmatic export-tar" action to export an archive to a tar-forma…

…tted file or stream (#300).

NEWS

@@ -1,4 +1,5 @@
-1.5.9.dev0
+1.5.9
+ * #300: Add "borgmatic export-tar" action to export an archive to a tar-formatted file or stream.
  * #339: Fix for intermittent timing-related test failure of logging function.
  * Clarify database documentation about excluding named pipes and character/block devices to prevent
    hangs.

borgmatic/borg/export_tar.py

@@ -0,0 +1,64 @@
+import logging
+import os
+
+from borgmatic.execute import DO_NOT_CAPTURE, execute_command
+
+logger = logging.getLogger(__name__)
+
+
+def export_tar_archive(
+    dry_run,
+    repository,
+    archive,
+    paths,
+    destination_path,
+    storage_config,
+    local_path='borg',
+    remote_path=None,
+    tar_filter=None,
+    files=False,
+    strip_components=None,
+):
+    '''
+    Given a dry-run flag, a local or remote repository path, an archive name, zero or more paths to
+    export from the archive, a destination path to export to, a storage configuration dict, optional
+    local and remote Borg paths, an optional filter program, whether to include per-file details,
+    and an optional number of path components to strip, export the archive into the given
+    destination path as a tar-formatted file.
+
+    If the destination path is "-", then stream the output to stdout instead of to a file.
+    '''
+    umask = storage_config.get('umask', None)
+    lock_wait = storage_config.get('lock_wait', None)
+
+    full_command = (
+        (local_path, 'export-tar')
+        + (('--remote-path', remote_path) if remote_path else ())
+        + (('--umask', str(umask)) if umask else ())
+        + (('--lock-wait', str(lock_wait)) if lock_wait else ())
+        + (('--info',) if logger.getEffectiveLevel() == logging.INFO else ())
+        + (('--list',) if files else ())
+        + (('--debug', '--show-rc') if logger.isEnabledFor(logging.DEBUG) else ())
+        + (('--dry-run',) if dry_run else ())
+        + (('--tar-filter', tar_filter) if tar_filter else ())
+        + (('--strip-components', str(strip_components)) if strip_components else ())
+        + ('::'.join((repository if ':' in repository else os.path.abspath(repository), archive)),)
+        + (destination_path,)
+        + (tuple(paths) if paths else ())
+    )
+
+    if files and logger.getEffectiveLevel() == logging.WARNING:
+        output_log_level = logging.WARNING
+    else:
+        output_log_level = logging.INFO
+
+    if dry_run:
+        logging.info('{}: Skipping export to tar file (dry run)'.format(repository))
+        return
+
+    execute_command(
+        full_command,
+        output_file=DO_NOT_CAPTURE if destination_path == '-' else None,
+        output_log_level=output_log_level,
+        borg_local_path=local_path,
+    )

borgmatic/commands/arguments.py

@@ -9,6 +9,7 @@
     'create': ['--create', '-C'],
     'check': ['--check', '-k'],
     'extract': ['--extract', '-x'],
+    'export-tar': ['--export-tar'],
     'mount': ['--mount', '-m'],
     'umount': ['--umount', '-u'],
     'restore': ['--restore', '-r'],
@@ -358,6 +359,52 @@ def parse_arguments(*unparsed_arguments):
         '-h', '--help', action='help', help='Show this help message and exit'
     )
 
+    export_tar_parser = subparsers.add_parser(
+        'export-tar',
+        aliases=SUBPARSER_ALIASES['export-tar'],
+        help='Export an archive to a tar-formatted file or stream',
+        description='Export an archive to a tar-formatted file or stream',
+        add_help=False,
+    )
+    export_tar_group = export_tar_parser.add_argument_group('export-tar arguments')
+    export_tar_group.add_argument(
+        '--repository',
+        help='Path of repository to export from, defaults to the configured repository if there is only one',
+    )
+    export_tar_group.add_argument(
+        '--archive', help='Name of archive to export (or "latest")', required=True
+    )
+    export_tar_group.add_argument(
+        '--path',
+        metavar='PATH',
+        nargs='+',
+        dest='paths',
+        help='Paths to export from archive, defaults to the entire archive',
+    )
+    export_tar_group.add_argument(
+        '--destination',
+        metavar='PATH',
+        dest='destination',
+        help='Path to destination export tar file, or "-" for stdout (but be careful about dirtying output with --verbosity or --files)',
+        required=True,
+    )
+    export_tar_group.add_argument(
+        '--tar-filter', help='Name of filter program to pipe data through'
+    )
+    export_tar_group.add_argument(
+        '--files', default=False, action='store_true', help='Show per-file details'
+    )
+    export_tar_group.add_argument(
+        '--strip-components',
+        type=int,
+        metavar='NUMBER',
+        dest='strip_components',
+        help='Number of leading path components to remove from each exported path. Skip paths with fewer elements',
+    )
+    export_tar_group.add_argument(
+        '-h', '--help', action='help', help='Show this help message and exit'
+    )
+
     mount_parser = subparsers.add_parser(
         'mount',
         aliases=SUBPARSER_ALIASES['mount'],

borgmatic/commands/borgmatic.py

@@ -12,6 +12,7 @@
 from borgmatic.borg import check as borg_check
 from borgmatic.borg import create as borg_create
 from borgmatic.borg import environment as borg_environment
+from borgmatic.borg import export_tar as borg_export_tar
 from borgmatic.borg import extract as borg_extract
 from borgmatic.borg import info as borg_info
 from borgmatic.borg import init as borg_init
@@ -347,6 +348,30 @@ def run_actions(
                 strip_components=arguments['extract'].strip_components,
                 progress=arguments['extract'].progress,
             )
+    if 'export-tar' in arguments:
+        if arguments['export-tar'].repository is None or validate.repositories_match(
+            repository, arguments['export-tar'].repository
+        ):
+            logger.info(
+                '{}: Exporting archive {} as tar file'.format(
+                    repository, arguments['export-tar'].archive
+                )
+            )
+            borg_export_tar.export_tar_archive(
+                global_arguments.dry_run,
+                repository,
+                borg_list.resolve_archive_name(
+                    repository, arguments['export-tar'].archive, storage, local_path, remote_path
+                ),
+                arguments['export-tar'].paths,
+                arguments['export-tar'].destination,
+                storage,
+                local_path=local_path,
+                remote_path=remote_path,
+                tar_filter=arguments['export-tar'].tar_filter,
+                files=arguments['export-tar'].files,
+                strip_components=arguments['export-tar'].strip_components,
+            )
     if 'mount' in arguments:
         if arguments['mount'].repository is None or validate.repositories_match(
             repository, arguments['mount'].repository

setup.py

@@ -1,6 +1,6 @@
 from setuptools import find_packages, setup
 
-VERSION = '1.5.9.dev0'
+VERSION = '1.5.9'
 
 
 setup(