Add FastAPI REST API service with CRUD operations

- Created main FastAPI application with CORS middleware
- Added SQLite database configuration with SQLAlchemy
- Implemented Items model with create, read, update, delete operations
- Set up Alembic migrations for database schema management
- Added comprehensive API endpoints at /api/v1/items/
- Included health check endpoint at /health
- Added proper Pydantic schemas for request/response validation
- Updated README with complete documentation and usage instructions
- Configured Ruff for code linting and formatting

README.md

@@ -1,3 +1,85 @@
-# FastAPI Application
+# REST API Service
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+A FastAPI-based REST API service with CRUD operations, SQLite database, and Alembic migrations.
+
+## Features
+
+- FastAPI framework with automatic API documentation
+- SQLite database with SQLAlchemy ORM
+- Database migrations with Alembic
+- CRUD operations for Items
+- CORS enabled for all origins
+- Health check endpoint
+- Automatic OpenAPI documentation
+
+## Installation
+
+1. Install dependencies:
+```bash
+pip install -r requirements.txt
+```
+
+## Running the Application
+
+Start the development server:
+```bash
+uvicorn main:app --reload
+```
+
+The API will be available at `http://localhost:8000`
+
+## API Documentation
+
+- Swagger UI: `http://localhost:8000/docs`
+- ReDoc: `http://localhost:8000/redoc`
+- OpenAPI JSON: `http://localhost:8000/openapi.json`
+
+## API Endpoints
+
+### Root
+- `GET /` - Service information
+
+### Health Check
+- `GET /health` - Health status
+
+### Items (CRUD)
+- `POST /api/v1/items/` - Create a new item
+- `GET /api/v1/items/` - List all items (with pagination)
+- `GET /api/v1/items/{item_id}` - Get specific item
+- `PUT /api/v1/items/{item_id}` - Update specific item
+- `DELETE /api/v1/items/{item_id}` - Delete specific item
+
+## Database
+
+The application uses SQLite with the database file stored at `/app/storage/db/db.sqlite`.
+
+### Migrations
+
+Database migrations are managed with Alembic. The migration files are in the `alembic/versions/` directory.
+
+## Project Structure
+
+```
+├── main.py                 # FastAPI application entry point
+├── requirements.txt        # Python dependencies
+├── alembic.ini            # Alembic configuration
+├── alembic/               # Database migrations
+│   ├── env.py
+│   ├── script.py.mako
+│   └── versions/
+│       └── 001_create_items_table.py
+└── app/
+    ├── api/               # API routes
+    │   └── items.py
+    ├── db/                # Database configuration
+    │   ├── base.py
+    │   └── session.py
+    ├── models/            # SQLAlchemy models
+    │   └── item.py
+    └── schemas/           # Pydantic schemas
+        └── item.py
+```
+
+## Environment Variables
+
+No environment variables are required for basic operation. The application uses SQLite with a file-based database.

alembic.ini

@@ -0,0 +1,41 @@
+[alembic]
+script_location = alembic
+prepend_sys_path = .
+version_path_separator = os
+sqlalchemy.url = sqlite:////app/storage/db/db.sqlite
+
+[post_write_hooks]
+
+[loggers]
+keys = root,sqlalchemy,alembic
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = WARN
+handlers = console
+qualname =
+
+[logger_sqlalchemy]
+level = WARN
+handlers =
+qualname = sqlalchemy.engine
+
+[logger_alembic]
+level = INFO
+handlers =
+qualname = alembic
+
+[handler_console]
+class = StreamHandler
+args = (sys.stderr,)
+level = NOTSET
+formatter = generic
+
+[formatter_generic]
+format = %(levelname)-5.5s [%(name)s] %(message)s
+datefmt = %H:%M:%S

alembic/env.py

@@ -0,0 +1,50 @@
+from logging.config import fileConfig
+from sqlalchemy import engine_from_config
+from sqlalchemy import pool
+from alembic import context
+import sys
+import os
+
+sys.path.append(os.path.dirname(os.path.dirname(__file__)))
+
+from app.db.base 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:
+    url = config.get_main_option("sqlalchemy.url")
+    context.configure(
+        url=url,
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def run_migrations_online() -> None:
+    connectable = engine_from_config(
+        config.get_section(config.config_ini_section),
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+
+    with connectable.connect() as connection:
+        context.configure(connection=connection, target_metadata=target_metadata)
+
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()

alembic/script.py.mako

@@ -0,0 +1,24 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+
+"""
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+# revision identifiers, used by Alembic.
+revision = ${repr(up_revision)}
+down_revision = ${repr(down_revision)}
+branch_labels = ${repr(branch_labels)}
+depends_on = ${repr(depends_on)}
+
+
+def upgrade() -> None:
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade() -> None:
+    ${downgrades if downgrades else "pass"}

alembic/versions/001_create_items_table.py

@@ -0,0 +1,41 @@
+"""create items table
+
+Revision ID: 001
+Revises:
+Create Date: 2024-01-01 00:00:00.000000
+
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+# revision identifiers, used by Alembic.
+revision = "001"
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "items",
+        sa.Column("id", sa.Integer(), nullable=False),
+        sa.Column("name", sa.String(length=100), nullable=False),
+        sa.Column("description", sa.Text(), nullable=True),
+        sa.Column(
+            "created_at",
+            sa.DateTime(timezone=True),
+            server_default=sa.text("(CURRENT_TIMESTAMP)"),
+            nullable=True,
+        ),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=True),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_index(op.f("ix_items_id"), "items", ["id"], unique=False)
+    op.create_index(op.f("ix_items_name"), "items", ["name"], unique=False)
+
+
+def downgrade() -> None:
+    op.drop_index(op.f("ix_items_name"), table_name="items")
+    op.drop_index(op.f("ix_items_id"), table_name="items")
+    op.drop_table("items")

app/api/items.py

@@ -0,0 +1,57 @@
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+from typing import List
+from app.db.session import get_db
+from app.models.item import Item
+from app.schemas.item import Item as ItemSchema, ItemCreate, ItemUpdate
+
+router = APIRouter()
+
+
+@router.post("/items/", response_model=ItemSchema, status_code=status.HTTP_201_CREATED)
+def create_item(item: ItemCreate, db: Session = Depends(get_db)):
+    db_item = Item(**item.dict())
+    db.add(db_item)
+    db.commit()
+    db.refresh(db_item)
+    return db_item
+
+
+@router.get("/items/", response_model=List[ItemSchema])
+def read_items(skip: int = 0, limit: int = 100, db: Session = Depends(get_db)):
+    items = db.query(Item).offset(skip).limit(limit).all()
+    return items
+
+
+@router.get("/items/{item_id}", response_model=ItemSchema)
+def read_item(item_id: int, db: Session = Depends(get_db)):
+    item = db.query(Item).filter(Item.id == item_id).first()
+    if item is None:
+        raise HTTPException(status_code=404, detail="Item not found")
+    return item
+
+
+@router.put("/items/{item_id}", response_model=ItemSchema)
+def update_item(item_id: int, item_update: ItemUpdate, db: Session = Depends(get_db)):
+    item = db.query(Item).filter(Item.id == item_id).first()
+    if item is None:
+        raise HTTPException(status_code=404, detail="Item not found")
+
+    update_data = item_update.dict(exclude_unset=True)
+    for field, value in update_data.items():
+        setattr(item, field, value)
+
+    db.commit()
+    db.refresh(item)
+    return item
+
+
+@router.delete("/items/{item_id}")
+def delete_item(item_id: int, db: Session = Depends(get_db)):
+    item = db.query(Item).filter(Item.id == item_id).first()
+    if item is None:
+        raise HTTPException(status_code=404, detail="Item not found")
+
+    db.delete(item)
+    db.commit()
+    return {"message": "Item deleted successfully"}

app/db/base.py

@@ -0,0 +1,17 @@
+from sqlalchemy import create_engine
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import sessionmaker
+from pathlib import Path
+
+DB_DIR = Path("/app/storage/db")
+DB_DIR.mkdir(parents=True, exist_ok=True)
+
+SQLALCHEMY_DATABASE_URL = f"sqlite:///{DB_DIR}/db.sqlite"
+
+engine = create_engine(
+    SQLALCHEMY_DATABASE_URL, connect_args={"check_same_thread": False}
+)
+
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+Base = declarative_base()

app/db/session.py

@@ -0,0 +1,9 @@
+from .base import SessionLocal
+
+
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()

app/models/item.py

@@ -0,0 +1,13 @@
+from sqlalchemy import Column, Integer, String, Text, DateTime
+from sqlalchemy.sql import func
+from app.db.base import Base
+
+
+class Item(Base):
+    __tablename__ = "items"
+
+    id = Column(Integer, primary_key=True, index=True)
+    name = Column(String(100), nullable=False, index=True)
+    description = Column(Text, nullable=True)
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now())

app/schemas/item.py

@@ -0,0 +1,26 @@
+from pydantic import BaseModel
+from datetime import datetime
+from typing import Optional
+
+
+class ItemBase(BaseModel):
+    name: str
+    description: Optional[str] = None
+
+
+class ItemCreate(ItemBase):
+    pass
+
+
+class ItemUpdate(BaseModel):
+    name: Optional[str] = None
+    description: Optional[str] = None
+
+
+class Item(ItemBase):
+    id: int
+    created_at: datetime
+    updated_at: Optional[datetime] = None
+
+    class Config:
+        from_attributes = True

main.py

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+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+import uvicorn
+from app.api.items import router as items_router
+from app.db.base import engine, Base
+
+Base.metadata.create_all(bind=engine)
+
+app = FastAPI(
+    title="REST API Service",
+    description="A FastAPI REST API service",
+    version="1.0.0",
+    openapi_url="/openapi.json",
+)
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+app.include_router(items_router, prefix="/api/v1", tags=["items"])
+
+
+@app.get("/")
+async def root():
+    return {
+        "title": "REST API Service",
+        "documentation": "/docs",
+        "health_check": "/health",
+    }
+
+
+@app.get("/health")
+async def health_check():
+    return {"status": "healthy", "service": "REST API Service"}
+
+
+if __name__ == "__main__":
+    uvicorn.run(app, host="0.0.0.0", port=8000)

requirements.txt

@@ -0,0 +1,7 @@
+fastapi==0.104.1
+uvicorn[standard]==0.24.0
+sqlalchemy==2.0.23
+alembic==1.12.1
+python-multipart==0.0.6
+pydantic==2.5.0
+ruff==0.1.6