remove dry_run_db and replace it with db_url in config

freqtrade/arguments.py

@@ -95,20 +95,23 @@ class Arguments(object):
         )
         self.parser.add_argument(
             '--dynamic-whitelist',
-            help='dynamically generate and update whitelist \
-                                  based on 24h BaseVolume (Default 20 currencies)',  # noqa
+            help='dynamically generate and update whitelist'
+                 ' based on 24h BaseVolume (default: %(default)s)',
             dest='dynamic_whitelist',
             const=constants.DYNAMIC_WHITELIST,
+            default=constants.DYNAMIC_WHITELIST,
             type=int,
             metavar='INT',
             nargs='?',
         )
         self.parser.add_argument(
-            '--dry-run-db',
-            help='Force dry run to use a local DB "tradesv3.dry_run.sqlite" \
-                                  instead of memory DB. Work only if dry_run is enabled.',
-            action='store_true',
-            dest='dry_run_db',
+            '--db-url',
+            help='Override trades database URL, this is useful if dry_run is enabled'
+                 ' or in custom deployments (default: %(default)s)',
+            dest='db_url',
+            default=constants.DEFAULT_DB_URL,
+            type=str,
+            metavar='PATH',
         )
 
     @staticmethod
@@ -277,13 +280,6 @@ class Arguments(object):
             default=None
         )
 
-        self.parser.add_argument(
-            '-db', '--db-url',
-            help='Show trades stored in database.',
-            dest='db_url',
-            default=None
-        )
-
     def testdata_dl_options(self) -> None:
         """
         Parses given arguments for testdata download

freqtrade/configuration.py

@@ -97,16 +97,21 @@ class Configuration(object):
                 '(not applicable with Backtesting and Hyperopt)'
             )
 
-        # Add dry_run_db if found and the bot in dry run
-        if self.args.dry_run_db and config.get('dry_run', False):
-            config.update({'dry_run_db': True})
-            logger.info('Parameter --dry-run-db detected ...')
+        if self.args.db_url and config.get('db_url', None):
+            config.update({'db_url': self.args.db_url})
+            logger.info('Parameter --db-url detected ...')
 
-        if config.get('dry_run_db', False):
-            if config.get('dry_run', False):
-                logger.info('Dry_run will use the DB file: "tradesv3.dry_run.sqlite"')
-            else:
-                logger.info('Dry run is disabled. (--dry_run_db ignored)')
+        if config.get('dry_run', False):
+            logger.info('Dry run is enabled')
+            if config.get('db_url') in [None, constants.DEFAULT_DB_URL]:
+                # Default to in-memory db for dry_run if not specified
+                config['db_url'] = 'sqlite://'
+        else:
+            if not config.get('db_url', None):
+                config['db_url'] = constants.DEFAULT_DB_URL
+            logger.info('Dry run is disabled')
+
+        logger.info('Using DB: "{}"'.format(config['db_url']))
 
         # Check if the exchange set by the user is supported
         self.check_exchange(config)

freqtrade/constants.py

@@ -9,6 +9,7 @@ TICKER_INTERVAL = 5  # min
 HYPEROPT_EPOCH = 100  # epochs
 RETRY_TIMEOUT = 30  # sec
 DEFAULT_STRATEGY = 'DefaultStrategy'
+DEFAULT_DB_URL = 'sqlite:///tradesv3.sqlite'
 
 TICKER_INTERVAL_MINUTES = {
     '1m': 1,
@@ -83,6 +84,7 @@ CONF_SCHEMA = {
             },
             'required': ['enabled', 'token', 'chat_id']
         },
+        'db_url': {'type': 'string'},
         'initial_state': {'type': 'string', 'enum': ['running', 'stopped']},
         'internals': {
             'type': 'object',