Added Alembic for migrations

migrations/env.py

@@ -0,0 +1,68 @@
+"""Alembic environment file."""
+
+import asyncio
+from logging.config import fileConfig
+
+from alembic import context
+from sqlalchemy.engine import Connection
+
+from spoolman.database.database import Database, get_connection_url
+from spoolman.database.models import Base
+
+config = context.config
+
+if config.config_file_name is not None:
+    fileConfig(config.config_file_name)
+
+target_metadata = Base.metadata
+
+
+def run_migrations_offline() -> None:
+    """Run migrations in 'offline' mode.
+
+    This configures the context with just a URL
+    and not an Engine, though an Engine is acceptable
+    here as well.  By skipping the Engine creation
+    we don't even need a DBAPI to be available.
+
+    Calls to context.execute() here emit the given string to the
+    script output.
+
+    """
+    context.configure(
+        url=get_connection_url(),
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def do_run_migrations(connection: Connection) -> None:
+    """Run migrations in 'online' mode."""
+    context.configure(connection=connection, target_metadata=target_metadata)
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+async def run_async_migrations() -> None:
+    """In this scenario we need to create an Engine and associate a connection with the context."""
+    db = Database(get_connection_url())
+    db.connect()
+
+    if db.engine is None:
+        raise RuntimeError("Engine not created.")
+
+    async with db.engine.connect() as connection:
+        await connection.run_sync(do_run_migrations)
+
+    await db.engine.dispose()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    asyncio.run(run_async_migrations())