alembic env.py supports env var DEXORDER_DB_URL

alembic/env.py

@@ -20,7 +20,13 @@ from sys import path
 path.append('src')
 import dexorder.database.model
 target_metadata = dexorder.database.model.Base.metadata
-if not config.get_main_option('sqlalchemy.url'):
+
+import os
+# Retrieve the database URL from the environment variable. We do not do a full load of
+db_url_env = os.getenv('DEXORDER_DB_URL')
+if db_url_env:
+    config.set_main_option('sqlalchemy.url', db_url_env)
+elif not config.get_main_option('sqlalchemy.url'):
     config.set_main_option('sqlalchemy.url', dexorder.config.db_url)
 
 # other values from the config, defined by the needs of env.py,