Fix database connection issues and improve error handling

alembic.ini

@@ -54,7 +54,8 @@ version_path_separator = os  # Use os.pathsep. Default configuration used to be
 # are written from script.py.mako
 # output_encoding = utf-8
 
-sqlalchemy.url = sqlite:////app/storage/db/db.sqlite
+# DB path is set programmatically in env.py
+sqlalchemy.url = driver://user:pass@localhost/dbname
 
 
 [post_write_hooks]

app/__init__.py

@@ -1 +1 @@
-# App package initialization
+# App package initialization

app/database/__init__.py

@@ -1 +1 @@
-# Database package initialization
+# Database package initialization

app/database/config.py

@@ -2,9 +2,13 @@ from sqlalchemy import create_engine
 from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy.orm import sessionmaker
 from pathlib import Path
+import os
 
-# Create the database directory if it doesn't exist
-DB_DIR = Path("/app/storage/db")
+# Get project root directory and create a storage directory
+PROJECT_ROOT = Path(
+    os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+)
+DB_DIR = PROJECT_ROOT / "storage" / "db"
 DB_DIR.mkdir(parents=True, exist_ok=True)
 
 # SQLite database URL
@@ -12,8 +16,7 @@ SQLALCHEMY_DATABASE_URL = f"sqlite:///{DB_DIR}/db.sqlite"
 
 # Create the SQLAlchemy engine
 engine = create_engine(
-    SQLALCHEMY_DATABASE_URL,
-    connect_args={"check_same_thread": False}
+    SQLALCHEMY_DATABASE_URL, connect_args={"check_same_thread": False}
 )
 
 # Create a SessionLocal class
@@ -22,10 +25,28 @@ SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
 # Create a Base class for declarative models
 Base = declarative_base()
 
+
+# Create tables (important for first run)
+def create_tables():
+    Base.metadata.create_all(bind=engine)
+
+
 # Dependency to get a database session
 def get_db():
     db = SessionLocal()
     try:
+        # Test the connection
+        db.execute("SELECT 1")
         yield db
+    except Exception as e:
+        # Log the error (in a real-world application)
+        print(f"Database connection error: {e}")
+        # Provide a user-friendly error
+        from fastapi import HTTPException, status
+
+        raise HTTPException(
+            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
+            detail="Database connection error. Please try again later.",
+        )
     finally:
-        db.close()
+        db.close()

app/database/models.py

@@ -2,6 +2,7 @@ from sqlalchemy import Boolean, Column, Integer, String, DateTime
 from sqlalchemy.sql import func
 from .config import Base
 
+
 class Todo(Base):
     __tablename__ = "todos"
 
@@ -10,4 +11,4 @@ class Todo(Base):
     description = Column(String, nullable=True)
     completed = Column(Boolean, default=False)
     created_at = Column(DateTime(timezone=True), server_default=func.now())
-    updated_at = Column(DateTime(timezone=True), onupdate=func.now())
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now())

main.py

@@ -7,12 +7,13 @@ from pydantic import BaseModel
 from datetime import datetime
 
 # Import database models and config
-from app.database.config import get_db
+from app.database.config import get_db, create_tables
 from app.database.models import Todo as TodoModel
 
 # Create tables if they don't exist
 # In production, you should use Alembic migrations instead
-# models.Base.metadata.create_all(bind=engine)
+create_tables()
+
 
 # Pydantic models for request and response
 class TodoBase(BaseModel):
@@ -20,16 +21,19 @@ class TodoBase(BaseModel):
     description: Optional[str] = None
     completed: bool = False
 
+
 class TodoCreate(TodoBase):
     pass
 
+
 class TodoResponse(TodoBase):
     id: int
     created_at: datetime
     updated_at: Optional[datetime] = None
 
     class Config:
-        orm_mode = True
+        from_attributes = True  # Updated for Pydantic v2 (replaces orm_mode)
+
 
 # Create the FastAPI app
 app = FastAPI(
@@ -47,13 +51,29 @@ app.add_middleware(
     allow_headers=["*"],
 )
 
+
 # Health endpoint
 @app.get("/health", tags=["Health"])
-async def health_check():
+async def health_check(db: Session = Depends(get_db)):
     """
-    Health check endpoint to verify the API is running.
+    Health check endpoint to verify the API is running and database connection is working.
     """
-    return {"status": "healthy"}
+    try:
+        # Test database connection
+        db.execute("SELECT 1").first()
+        return {
+            "status": "healthy",
+            "database": "connected",
+            "timestamp": datetime.now().isoformat(),
+        }
+    except Exception as e:
+        return {
+            "status": "unhealthy",
+            "database": "disconnected",
+            "error": str(e),
+            "timestamp": datetime.now().isoformat(),
+        }
+
 
 # Root endpoint
 @app.get("/", tags=["Root"])
@@ -63,18 +83,25 @@ async def root():
     """
     return {"message": "Welcome to Todo List API. Visit /docs for documentation."}
 
+
 # Todo API endpoints
-@app.post("/todos", response_model=TodoResponse, status_code=status.HTTP_201_CREATED, tags=["Todos"])
+@app.post(
+    "/todos",
+    response_model=TodoResponse,
+    status_code=status.HTTP_201_CREATED,
+    tags=["Todos"],
+)
 def create_todo(todo: TodoCreate, db: Session = Depends(get_db)):
     """
     Create a new todo item.
     """
-    db_todo = TodoModel(**todo.dict())
+    db_todo = TodoModel(**todo.model_dump())
     db.add(db_todo)
     db.commit()
     db.refresh(db_todo)
     return db_todo
 
+
 @app.get("/todos", response_model=List[TodoResponse], tags=["Todos"])
 def read_todos(skip: int = 0, limit: int = 100, db: Session = Depends(get_db)):
     """
@@ -83,6 +110,7 @@ def read_todos(skip: int = 0, limit: int = 100, db: Session = Depends(get_db)):
     todos = db.query(TodoModel).offset(skip).limit(limit).all()
     return todos
 
+
 @app.get("/todos/{todo_id}", response_model=TodoResponse, tags=["Todos"])
 def read_todo(todo_id: int, db: Session = Depends(get_db)):
     """
@@ -93,6 +121,7 @@ def read_todo(todo_id: int, db: Session = Depends(get_db)):
         raise HTTPException(status_code=404, detail="Todo not found")
     return db_todo
 
+
 @app.put("/todos/{todo_id}", response_model=TodoResponse, tags=["Todos"])
 def update_todo(todo_id: int, todo: TodoCreate, db: Session = Depends(get_db)):
     """
@@ -101,16 +130,22 @@ def update_todo(todo_id: int, todo: TodoCreate, db: Session = Depends(get_db)):
     db_todo = db.query(TodoModel).filter(TodoModel.id == todo_id).first()
     if db_todo is None:
         raise HTTPException(status_code=404, detail="Todo not found")
-    
+
     # Update todo item fields
-    for key, value in todo.dict().items():
+    for key, value in todo.model_dump().items():
         setattr(db_todo, key, value)
-    
+
     db.commit()
     db.refresh(db_todo)
     return db_todo
 
-@app.delete("/todos/{todo_id}", status_code=status.HTTP_204_NO_CONTENT, response_model=None, tags=["Todos"])
+
+@app.delete(
+    "/todos/{todo_id}",
+    status_code=status.HTTP_204_NO_CONTENT,
+    response_model=None,
+    tags=["Todos"],
+)
 def delete_todo(todo_id: int, db: Session = Depends(get_db)):
     """
     Delete a todo item.
@@ -118,11 +153,12 @@ def delete_todo(todo_id: int, db: Session = Depends(get_db)):
     db_todo = db.query(TodoModel).filter(TodoModel.id == todo_id).first()
     if db_todo is None:
         raise HTTPException(status_code=404, detail="Todo not found")
-    
+
     db.delete(db_todo)
     db.commit()
     return None
 
+
 # For local development
 if __name__ == "__main__":
-    uvicorn.run("main:app", host="0.0.0.0", port=8000, reload=True)
+    uvicorn.run("main:app", host="0.0.0.0", port=8000, reload=True)

migrations/__init__.py

@@ -1 +1 @@
-# Migrations package initialization
+# Migrations package initialization

migrations/env.py

@@ -71,7 +71,7 @@ def run_migrations_online() -> None:
     with connectable.connect() as connection:
         # Check if we're dealing with SQLite
         is_sqlite = connection.dialect.name == "sqlite"
-        
+
         context.configure(
             connection=connection,
             target_metadata=target_metadata,
@@ -85,4 +85,4 @@ def run_migrations_online() -> None:
 if context.is_offline_mode():
     run_migrations_offline()
 else:
-    run_migrations_online()
+    run_migrations_online()

migrations/versions/__init__.py

@@ -1 +1 @@
-# Migrations versions package initialization
+# Migrations versions package initialization

migrations/versions/initial_migration.py

@@ -1,16 +1,17 @@
 """Initial migration
 
 Revision ID: 001
-Revises: 
+Revises:
 Create Date: 2023-10-24
 
 """
+
 from alembic import op
 import sqlalchemy as sa
 
 
 # revision identifiers, used by Alembic.
-revision = '001'
+revision = "001"
 down_revision = None
 branch_labels = None
 depends_on = None
@@ -19,21 +20,25 @@ depends_on = None
 def upgrade() -> None:
     # Create todos table
     op.create_table(
-        'todos',
-        sa.Column('id', sa.Integer(), nullable=False),
-        sa.Column('title', sa.String(), nullable=False),
-        sa.Column('description', sa.String(), nullable=True),
-        sa.Column('completed', sa.Boolean(), nullable=False, default=False),
-        sa.Column('created_at', sa.DateTime(timezone=True), server_default=sa.text('(CURRENT_TIMESTAMP)')),
-        sa.Column('updated_at', sa.DateTime(timezone=True), nullable=True),
-        sa.PrimaryKeyConstraint('id')
+        "todos",
+        sa.Column("id", sa.Integer(), nullable=False),
+        sa.Column("title", sa.String(), nullable=False),
+        sa.Column("description", sa.String(), nullable=True),
+        sa.Column("completed", sa.Boolean(), nullable=False, default=False),
+        sa.Column(
+            "created_at",
+            sa.DateTime(timezone=True),
+            server_default=sa.text("(CURRENT_TIMESTAMP)"),
+        ),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=True),
+        sa.PrimaryKeyConstraint("id"),
     )
-    op.create_index(op.f('ix_todos_id'), 'todos', ['id'], unique=False)
-    op.create_index(op.f('ix_todos_title'), 'todos', ['title'], unique=False)
+    op.create_index(op.f("ix_todos_id"), "todos", ["id"], unique=False)
+    op.create_index(op.f("ix_todos_title"), "todos", ["title"], unique=False)
 
 
 def downgrade() -> None:
     # Drop todos table
-    op.drop_index(op.f('ix_todos_title'), table_name='todos')
-    op.drop_index(op.f('ix_todos_id'), table_name='todos')
-    op.drop_table('todos')
+    op.drop_index(op.f("ix_todos_title"), table_name="todos")
+    op.drop_index(op.f("ix_todos_id"), table_name="todos")
+    op.drop_table("todos")