Mention placeholders for repositories in documentation; fix #369

Reviewed-on: https://projects.torsion.org/witten/borgmatic/pulls/371

borgmatic/config/schema.yaml

@@ -27,12 +27,14 @@ map:
                 desc: |
                     Paths to local or remote repositories (required). Tildes are
                     expanded. Multiple repositories are backed up to in
-                    sequence. See ssh_command for SSH options like identity file
+                    sequence. Borg placeholders can be used. See the output of
-                    or port.
+                    "borg help placeholders" for details.
+                    See ssh_command for SSH options like identity file or port.
                     If systemd service is used, then add local repository paths
                     in the systemd service file to the ReadWritePaths list.
                 example:
                     - user@backupserver:sourcehostname.borg
+                    - "user@backupserver:{fqdn}"
             one_file_system:
                 type: bool
                 desc: |

tests/unit/borg/test_create.py

@@ -1326,6 +1326,34 @@ def test_create_archive_with_archive_name_format_accepts_borg_placeholders():
     )
 
 
+def test_create_archive_with_repository_accepts_borg_placeholders():
+    flexmock(module).should_receive('borgmatic_source_directories').and_return([])
+    flexmock(module).should_receive('deduplicate_directories').and_return(('foo', 'bar'))
+    flexmock(module).should_receive('map_directories_to_devices').and_return({})
+    flexmock(module).should_receive('_expand_directories').and_return(())
+    flexmock(module).should_receive('_expand_home_directories').and_return(())
+    flexmock(module).should_receive('_write_pattern_file').and_return(None)
+    flexmock(module).should_receive('_make_pattern_flags').and_return(())
+    flexmock(module).should_receive('_make_exclude_flags').and_return(())
+    flexmock(module).should_receive('execute_command').with_args(
+        ('borg', 'create', '{fqdn}::Documents_{hostname}-{now}', 'foo', 'bar'),
+        output_log_level=logging.INFO,
+        output_file=None,
+        borg_local_path='borg',
+    )
+
+    module.create_archive(
+        dry_run=False,
+        repository='{fqdn}',
+        location_config={
+            'source_directories': ['foo', 'bar'],
+            'repositories': ['{fqdn}'],
+            'exclude_patterns': None,
+        },
+        storage_config={'archive_name_format': 'Documents_{hostname}-{now}'},
+    )
+
+
 def test_create_archive_with_extra_borg_options_calls_borg_with_extra_options():
     flexmock(module).should_receive('borgmatic_source_directories').and_return([])
     flexmock(module).should_receive('deduplicate_directories').and_return(('foo', 'bar'))