Fix Alembic migration import error in containerized environment

alembic/env.py

@@ -1,11 +1,19 @@
 """
 Alembic environment script for database migrations
 """
+import sys
 from logging.config import fileConfig
+from pathlib import Path
 
 from alembic import context
+
+# Custom module to help with finding modules in containerized environments
+from alembic.find_modules import setup_python_path
 from sqlalchemy import engine_from_config, pool
 
+# Setup Python path to find app modules in various environments
+setup_python_path()
+
 # this is the Alembic Config object, which provides
 # access to the values within the .ini file in use.
 config = context.config
@@ -15,10 +23,43 @@ config = context.config
 if config.config_file_name is not None:
     fileConfig(config.config_file_name)
 
-# add your model's MetaData object here
-# for 'autogenerate' support
-from app.models import Todo  # noqa
-from app.core.database import Base  # noqa
+# Try different import strategies to handle various deployment environments
+try:
+    # Standard import approach
+    from app.models import Todo  # noqa
+    from app.core.database import Base  # noqa
+except ImportError:
+    try:
+        # Path-based import for some container setups
+        import importlib.util
+        import sys
+
+        # Try to find the module file
+        for base_path in sys.path:
+            model_path = Path(base_path) / "app" / "models" / "todo.py"
+            db_path = Path(base_path) / "app" / "core" / "database.py"
+
+            if model_path.exists() and db_path.exists():
+                # Load the todo module
+                spec = importlib.util.spec_from_file_location("todo", model_path)
+                todo_module = importlib.util.module_from_spec(spec)
+                spec.loader.exec_module(todo_module)
+
+                # Load the database module
+                spec = importlib.util.spec_from_file_location("database", db_path)
+                db_module = importlib.util.module_from_spec(spec)
+                spec.loader.exec_module(db_module)
+
+                # Get the required objects
+                Todo = getattr(todo_module, "Todo")
+                Base = getattr(db_module, "Base")
+                break
+        else:
+            raise ImportError("Could not find app modules in any path")
+    except Exception as e:
+        print(f"Error importing models: {e}")
+        print(f"Current sys.path: {sys.path}")
+        raise
 
 target_metadata = Base.metadata
 

alembic/find_modules.py

@@ -0,0 +1,29 @@
+"""
+Module finder helper for Alembic migrations in containerized environments.
+"""
+import sys
+from pathlib import Path
+
+
+def setup_python_path():
+    """
+    Add necessary paths to Python's sys.path to make imports work
+    in various environments including Docker containers
+    """
+    # Get the directory where this script is located
+    current_dir = Path(__file__).resolve().parent
+
+    # The project root is one level up from the 'alembic' directory
+    project_root = current_dir.parent
+
+    # Add the project root to the Python path if it's not already there
+    if str(project_root) not in sys.path:
+        sys.path.insert(0, str(project_root))
+
+    # Check if we're in a Docker container with code mounted at /app/repo
+    repo_path = Path('/app/repo')
+    if repo_path.exists() and str(repo_path) not in sys.path:
+        sys.path.insert(0, str(repo_path))
+
+    # Return the actual Python paths used, for debugging
+    return sys.path

test_imports.py

@@ -0,0 +1,50 @@
+"""
+Test script to verify imports work correctly.
+This can be run both locally and in the container to verify the setup.
+"""
+import os
+import sys
+
+# Print current working directory
+print(f"Current working directory: {os.getcwd()}")
+
+# Print Python path
+print(f"Python path: {sys.path}")
+
+# Try to import the app modules
+try:
+    # Add current directory to path
+    sys.path.insert(0, os.getcwd())
+
+    # Try importing the models
+    from app.models import Todo
+    print(f"Successfully imported Todo from app.models: {Todo}")
+
+    from app.core.database import Base
+    print(f"Successfully imported Base from app.core.database: {Base}")
+
+    print("All imports succeeded!")
+except Exception as e:
+    print(f"Error importing modules: {e}")
+
+    # Try a different approach for containerized environments
+    try:
+        # Try to execute the find_modules code
+        sys.path.insert(0, os.path.join(os.getcwd(), 'alembic'))
+        from find_modules import setup_python_path
+
+        # Setup paths
+        paths = setup_python_path()
+        print(f"Updated paths: {paths}")
+
+        # Try importing again
+        from app.models import Todo
+        print(f"Successfully imported Todo after path setup: {Todo}")
+
+        from app.core.database import Base
+        print(f"Successfully imported Base after path setup: {Base}")
+
+        print("Imports succeeded after path setup!")
+    except Exception as inner_e:
+        print(f"Still failed after path setup: {inner_e}")
+        print("This might indicate a deeper issue with the module structure.")