Add an encryption option to repositories (#303).

NEWS

@@ -2,6 +2,10 @@
  * #303: Add flags for setting any borgmatic configuration option from the command-line. See the
    documentation for more information:
    https://torsion.org/borgmatic/docs/how-to/make-per-application-backups/#configuration-overrides
+ * #303: Add configuration options that serve as defaults for some (but not all) borgmatic
+   action flags. For example, each entry in "repositories:" now has an "encryption" option that
+   applies to the "repo-create" action. See the documentation for more information:
+   https://torsion.org/borgmatic/docs/reference/configuration/
  * #790, #821: Deprecate all "before_*", "after_*" and "on_error" command hooks in favor of more
    flexible "commands:". See the documentation for more information:
    https://torsion.org/borgmatic/docs/how-to/add-preparation-and-cleanup-steps-to-backups/

borgmatic/actions/repo_create.py

@@ -24,13 +24,21 @@ def run_repo_create(
         return
 
     logger.info('Creating repository')
+
+    encryption_mode = repo_create_arguments.encryption_mode or repository.get('encryption')
+
+    if not encryption_mode:
+        raise ValueError(
+            'With the repo-create action, either the --encryption flag or the repository encryption option is required.'
+        )
+
     borgmatic.borg.repo_create.create_repository(
         global_arguments.dry_run,
         repository['path'],
         config,
         local_borg_version,
         global_arguments,
-        repo_create_arguments.encryption_mode,
+        encryption_mode,
         repo_create_arguments.source_repository,
         repo_create_arguments.copy_crypt_key,
         repo_create_arguments.append_only,

borgmatic/commands/arguments.py

@@ -445,7 +445,10 @@ def make_parsers(schema, unparsed_arguments):
     config_paths = collect.get_default_config_paths(expand_home=True)
     unexpanded_config_paths = collect.get_default_config_paths(expand_home=False)
 
-    global_parser = ArgumentParser(add_help=False)
+    # allow_abbrev=False prevents the global parser from erroring about "ambiguous" options like
+    # --encryption. Such options are intended for an action parser rather than the global parser,
+    # and so we don't want to error on them here.
+    global_parser = ArgumentParser(allow_abbrev=False, add_help=False)
     global_group = global_parser.add_argument_group('global arguments')
 
     global_group.add_argument(
@@ -569,7 +572,6 @@ def make_parsers(schema, unparsed_arguments):
         '--encryption',
         dest='encryption_mode',
         help='Borg repository encryption mode',
-        required=True,
     )
     repo_create_group.add_argument(
         '--source-repository',

borgmatic/config/schema.yaml

@@ -45,6 +45,14 @@ properties:
                         and to make selecting the repository easier on the
                         command-line.
                     example: backupserver
+                encryption:
+                    type: string
+                    description: |
+                        The encryption mode with which to create the repository,
+                        only used for the repo-create action. To see the
+                        available encryption modes, run "borg init --help" with
+                        Borg 1 or "borg repo-create --help" with Borg 2.
+                    example: repokey-blake2
         description: |
             A required list of local or remote repositories with paths and
             optional labels (which can be used with the --repository flag to