Create REST API with FastAPI and SQLite

README.md

@@ -1,3 +1,126 @@
-# FastAPI Application
+# Generic REST API Service
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+A modern REST API service built with FastAPI and SQLite for handling item resources.
+
+## Features
+
+- FastAPI-based REST API with automatic OpenAPI documentation
+- SQLAlchemy ORM with SQLite database
+- Alembic database migrations
+- CRUD operations for item resources
+- Health check endpoint
+- Async-ready with uvicorn
+
+## Project Structure
+
+```
+.
+├── alembic.ini
+├── app/
+│   ├── api/
+│   │   ├── api.py
+│   │   └── endpoints/
+│   │       └── items.py
+│   ├── core/
+│   │   ├── config.py
+│   │   └── database.py
+│   ├── models/
+│   │   ├── base.py
+│   │   └── item.py
+│   └── schemas/
+│       └── item.py
+├── main.py
+├── migrations/
+│   ├── env.py
+│   ├── README
+│   ├── script.py.mako
+│   └── versions/
+│       └── 001_initial_migration.py
+└── requirements.txt
+```
+
+## Prerequisites
+
+- Python 3.8+
+- virtualenv (recommended)
+
+## Installation
+
+1. Clone the repository:
+   ```bash
+   git clone <repository-url>
+   cd <repository-directory>
+   ```
+
+2. Create and activate a virtual environment (optional but recommended):
+   ```bash
+   python -m venv venv
+   source venv/bin/activate  # On Windows: venv\Scripts\activate
+   ```
+
+3. Install dependencies:
+   ```bash
+   pip install -r requirements.txt
+   ```
+
+4. Initialize the database:
+   ```bash
+   alembic upgrade head
+   ```
+
+## Running the API
+
+Start the API server with:
+
+```bash
+uvicorn main:app --reload
+```
+
+The API will be available at http://localhost:8000
+
+## API Documentation
+
+FastAPI automatically generates interactive API documentation:
+
+- Swagger UI: http://localhost:8000/docs
+- ReDoc: http://localhost:8000/redoc
+
+## API Endpoints
+
+- **GET /health** - Health check endpoint
+- **GET /api/v1/items/** - List all items
+- **POST /api/v1/items/** - Create a new item
+- **GET /api/v1/items/{item_id}** - Get a specific item
+- **PUT /api/v1/items/{item_id}** - Update a specific item
+- **DELETE /api/v1/items/{item_id}** - Delete a specific item
+
+## Development
+
+### Database Migrations
+
+After modifying models, create a new migration:
+
+```bash
+alembic revision -m "description of changes"
+```
+
+Apply migrations:
+
+```bash
+alembic upgrade head
+```
+
+Revert migrations:
+
+```bash
+alembic downgrade -1  # Go back one migration
+```
+
+### Code Quality
+
+Run linting with Ruff:
+
+```bash
+ruff check .
+ruff check --fix .  # Auto-fix issues
+```

alembic.ini

@@ -0,0 +1,73 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = migrations
+
+# template used to generate migration files
+# file_template = %%(rev)s_%%(slug)s
+
+# timezone to use when rendering the date
+# within the migration file as well as the filename.
+# string value is passed to dateutil.tz.gettz()
+# leave blank for localtime
+# timezone =
+
+# max length of characters to apply to the
+# "slug" field
+# truncate_slug_length = 40
+
+# set to 'true' to run the environment during
+# the 'revision' command, regardless of autogenerate
+# revision_environment = false
+
+# set to 'true' to allow .pyc and .pyo files without
+# a source .py file to be detected as revisions in the
+# versions/ directory
+# sourceless = false
+
+# version location specification; this defaults
+# to alembic/versions.  When using multiple version
+# directories, initial revisions must be specified with --version-path
+# version_locations = %(here)s/bar %(here)s/bat alembic/versions
+
+# the output encoding used when revision files
+# are written from script.py.mako
+# output_encoding = utf-8
+
+sqlalchemy.url = sqlite:////app/storage/db/db.sqlite
+
+# Logging configuration
+[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

app/api/api.py

@@ -0,0 +1,6 @@
+from fastapi import APIRouter
+
+from app.api.endpoints import items
+
+api_router = APIRouter()
+api_router.include_router(items.router, prefix="/items", tags=["items"])

app/api/endpoints/items.py

@@ -0,0 +1,81 @@
+from typing import List
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+
+from app.core.database import get_db
+from app.models.item import Item
+from app.schemas.item import Item as ItemSchema
+from app.schemas.item import ItemCreate, ItemUpdate
+
+router = APIRouter()
+
+@router.get("/", response_model=List[ItemSchema])
+def read_items(
+    skip: int = 0, 
+    limit: int = 100, 
+    db: Session = Depends(get_db)
+):
+    """Get a list of items."""
+    items = db.query(Item).offset(skip).limit(limit).all()
+    return items
+
+@router.post("/", response_model=ItemSchema, status_code=status.HTTP_201_CREATED)
+def create_item(
+    item_in: ItemCreate, 
+    db: Session = Depends(get_db)
+):
+    """Create a new item."""
+    db_item = Item(
+        name=item_in.name,
+        description=item_in.description,
+        is_active=item_in.is_active
+    )
+    db.add(db_item)
+    db.commit()
+    db.refresh(db_item)
+    return db_item
+
+@router.get("/{item_id}", response_model=ItemSchema)
+def read_item(
+    item_id: str, 
+    db: Session = Depends(get_db)
+):
+    """Get an item by ID."""
+    db_item = db.query(Item).filter(Item.id == item_id).first()
+    if db_item is None:
+        raise HTTPException(status_code=404, detail="Item not found")
+    return db_item
+
+@router.put("/{item_id}", response_model=ItemSchema)
+def update_item(
+    item_id: str, 
+    item_in: ItemUpdate, 
+    db: Session = Depends(get_db)
+):
+    """Update an item."""
+    db_item = db.query(Item).filter(Item.id == item_id).first()
+    if db_item is None:
+        raise HTTPException(status_code=404, detail="Item not found")
+    
+    update_data = item_in.dict(exclude_unset=True)
+    for field, value in update_data.items():
+        setattr(db_item, field, value)
+    
+    db.add(db_item)
+    db.commit()
+    db.refresh(db_item)
+    return db_item
+
+@router.delete("/{item_id}", status_code=status.HTTP_204_NO_CONTENT, response_model=None)
+def delete_item(
+    item_id: str, 
+    db: Session = Depends(get_db)
+):
+    """Delete an item."""
+    db_item = db.query(Item).filter(Item.id == item_id).first()
+    if db_item is None:
+        raise HTTPException(status_code=404, detail="Item not found")
+    
+    db.delete(db_item)
+    db.commit()
+    return None

app/core/config.py

@@ -0,0 +1,27 @@
+from pathlib import Path
+from typing import Any, Dict, Optional
+
+from pydantic import BaseSettings, validator
+
+class Settings(BaseSettings):
+    """Application settings."""
+    API_V1_STR: str = "/api/v1"
+    PROJECT_NAME: str = "Generic REST API Service"
+    
+    # Configure database
+    DB_DIR: Path = Path("/app") / "storage" / "db"
+    SQLALCHEMY_DATABASE_URL: str = ""
+    
+    @validator("SQLALCHEMY_DATABASE_URL", pre=True)
+    def assemble_db_url(cls, v: Optional[str], values: Dict[str, Any]) -> str:
+        if v and len(v) > 0:
+            return v
+        
+        # Ensure DB directory exists
+        db_dir = values.get("DB_DIR")
+        if db_dir:
+            Path(db_dir).mkdir(parents=True, exist_ok=True)
+            
+        return f"sqlite:///{values.get('DB_DIR')}/db.sqlite"
+
+settings = Settings()

app/core/database.py

@@ -0,0 +1,26 @@
+from pathlib import Path
+from sqlalchemy import create_engine
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import sessionmaker
+
+# Ensure DB directory exists
+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()
+
+# Dependency to get DB session
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()

app/models/__init__.py

@@ -0,0 +1,3 @@
+from app.models.item import Item
+
+__all__ = ["Item"]

app/models/base.py

@@ -0,0 +1,20 @@
+import uuid
+from datetime import datetime
+
+from sqlalchemy import Column, DateTime, String
+from sqlalchemy.ext.declarative import declared_attr
+
+from app.core.database import Base
+
+class BaseModel(Base):
+    """Base SQLAlchemy model with common fields."""
+    
+    __abstract__ = True
+    
+    @declared_attr
+    def __tablename__(cls):
+        return cls.__name__.lower()
+    
+    id = Column(String(36), primary_key=True, index=True, default=lambda: str(uuid.uuid4()))
+    created_at = Column(DateTime, default=datetime.utcnow)
+    updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)

app/models/item.py

@@ -0,0 +1,9 @@
+from sqlalchemy import Column, String, Text, Boolean
+
+from app.models.base import BaseModel
+
+class Item(BaseModel):
+    """Item model."""
+    name = Column(String(100), index=True, nullable=False)
+    description = Column(Text, nullable=True)
+    is_active = Column(Boolean, default=True)

app/schemas/__init__.py

@@ -0,0 +1,3 @@
+from app.schemas.item import Item, ItemCreate, ItemUpdate
+
+__all__ = ["Item", "ItemCreate", "ItemUpdate"]

app/schemas/item.py

@@ -0,0 +1,32 @@
+from typing import Optional
+from datetime import datetime
+from pydantic import BaseModel
+
+class ItemBase(BaseModel):
+    """Base schema for Item."""
+    name: str
+    description: Optional[str] = None
+    is_active: bool = True
+
+class ItemCreate(ItemBase):
+    """Schema for creating an Item."""
+    pass
+
+class ItemUpdate(BaseModel):
+    """Schema for updating an Item."""
+    name: Optional[str] = None
+    description: Optional[str] = None
+    is_active: Optional[bool] = None
+
+class ItemInDBBase(ItemBase):
+    """Base schema for Item with DB fields."""
+    id: str
+    created_at: datetime
+    updated_at: datetime
+
+    class Config:
+        orm_mode = True
+
+class Item(ItemInDBBase):
+    """Schema for returning an Item."""
+    pass

main.py

@@ -0,0 +1,34 @@
+import uvicorn
+from fastapi import FastAPI, Depends
+from sqlalchemy.orm import Session
+from app.core.config import settings
+from app.core.database import get_db
+from app.api.api import api_router
+
+app = FastAPI(
+    title=settings.PROJECT_NAME,
+    openapi_url=f"{settings.API_V1_STR}/openapi.json"
+)
+
+# Include routers
+app.include_router(api_router, prefix=settings.API_V1_STR)
+
+# Health check endpoint
+@app.get("/health", tags=["health"])
+async def health(db: Session = Depends(get_db)):
+    """Health check endpoint that verifies API and database connectivity."""
+    try:
+        # Verify the database connection
+        db.execute("SELECT 1")
+        db_status = "ok"
+    except Exception as e:
+        db_status = f"error: {str(e)}"
+    
+    return {
+        "status": "ok",
+        "database": db_status,
+        "api_version": "1.0.0"
+    }
+
+if __name__ == "__main__":
+    uvicorn.run("main:app", host="0.0.0.0", port=8000, reload=True)

migrations/README

@@ -0,0 +1,6 @@
+Generic single-database configuration with an SQLite database.
+
+To run migrations:
+1. Update models in app/models/
+2. Run manual migration script generation (autogenerate is disabled)
+3. Apply migrations with `alembic upgrade head`

migrations/env.py

@@ -0,0 +1,81 @@
+from logging.config import fileConfig
+
+from sqlalchemy import engine_from_config
+from sqlalchemy import pool
+
+from alembic import context
+from app.core.database import Base
+
+# this is the Alembic Config object, which provides
+# access to the values within the .ini file in use.
+config = context.config
+
+# Interpret the config file for Python logging.
+# This line sets up loggers basically.
+fileConfig(config.config_file_name)
+
+# add your model's MetaData object here
+# for 'autogenerate' support
+# from myapp import mymodel
+# target_metadata = mymodel.Base.metadata
+target_metadata = Base.metadata
+
+# other values from the config, defined by the needs of env.py,
+# can be acquired:
+# my_important_option = config.get_main_option("my_important_option")
+# ... etc.
+
+
+def run_migrations_offline():
+    """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.
+
+    """
+    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():
+    """Run migrations in 'online' mode.
+
+    In this scenario we need to create an Engine
+    and associate a connection with the context.
+
+    """
+    connectable = engine_from_config(
+        config.get_section(config.config_ini_section),
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+
+    with connectable.connect() as connection:
+        is_sqlite = connection.dialect.name == 'sqlite'
+        context.configure(
+            connection=connection,
+            target_metadata=target_metadata,
+            render_as_batch=is_sqlite,  # Key configuration for SQLite
+        )
+
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()

migrations/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():
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade():
+    ${downgrades if downgrades else "pass"}

migrations/versions/001_initial_migration.py

@@ -0,0 +1,37 @@
+"""Initial migration
+
+Revision ID: 001
+Revises: 
+Create Date: 2023-10-22
+
+"""
+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():
+    # Create item table
+    op.create_table(
+        'item',
+        sa.Column('id', sa.String(36), primary_key=True, index=True),
+        sa.Column('created_at', sa.DateTime(), nullable=True),
+        sa.Column('updated_at', sa.DateTime(), nullable=True),
+        sa.Column('name', sa.String(100), index=True, nullable=False),
+        sa.Column('description', sa.Text(), nullable=True),
+        sa.Column('is_active', sa.Boolean(), default=True),
+    )
+    op.create_index(op.f('ix_item_id'), 'item', ['id'], unique=False)
+    op.create_index(op.f('ix_item_name'), 'item', ['name'], unique=False)
+
+
+def downgrade():
+    op.drop_index(op.f('ix_item_name'), table_name='item')
+    op.drop_index(op.f('ix_item_id'), table_name='item')
+    op.drop_table('item')

requirements.txt

@@ -0,0 +1,7 @@
+fastapi>=0.104.0
+uvicorn>=0.24.0
+sqlalchemy>=2.0.0
+pydantic>=2.4.0
+alembic>=1.12.0
+python-dotenv>=1.0.0
+ruff>=0.1.0