Add list_options setting (#306).

Reviewed-on: https://projects.torsion.org/borgmatic-collective/borgmatic/pulls/464

borgmatic/config/schema.yaml

@@ -749,6 +749,14 @@ properties:
                                 configured to trust the configured username
                                 without a password.
                             example: trustsome1
+                        list_options:
+                            type: string
+                            description: |
+                                Additional mysql options to pass directly to
+                                the mysql command that lists available
+                                databases, without performing any validation on
+                                them. See mysql documentation for details.
+                            example: --defaults-extra-file=my.cnf
                         options:
                             type: string
                             description: |

borgmatic/hooks/mysql.py

@@ -31,6 +31,7 @@ def database_names_to_dump(database, extra_environment, log_prefix, dry_run_labe
 
     show_command = (
         ('mysql',)
+        + (tuple(database['list_options'].split(' ')) if 'list_options' in database else ())
         + (('--host', database['hostname']) if 'hostname' in database else ())
         + (('--port', str(database['port'])) if 'port' in database else ())
         + (('--protocol', 'tcp') if 'hostname' in database or 'port' in database else ())

tests/unit/hooks/test_mysql.py

@@ -198,6 +198,24 @@ def test_dump_databases_runs_mysqldump_for_all_databases():
     assert module.dump_databases(databases, 'test.yaml', {}, dry_run=False) == [process]
 
 
+def test_database_names_to_dump_runs_mysql_with_list_options():
+    database = {'name': 'all', 'list_options': '--defaults-extra-file=my.cnf'}
+    flexmock(module).should_receive('execute_command').with_args(
+        (
+            'mysql',
+            '--defaults-extra-file=my.cnf',
+            '--skip-column-names',
+            '--batch',
+            '--execute',
+            'show schemas',
+        ),
+        output_log_level=None,
+        extra_environment=None,
+    ).and_return(('foo\nbar')).once()
+
+    assert module.database_names_to_dump(database, None, 'test.yaml', '') == ('foo', 'bar')
+
+
 def test_dump_databases_errors_for_missing_all_databases():
     databases = [{'name': 'all'}]
     process = flexmock()