Create a FastAPI REST API service with SQLite database

- Set up project structure
- Configure SQLite database with SQLAlchemy
- Create item model and schema
- Set up Alembic for database migrations
- Implement CRUD operations for items
- Add health check endpoint
- Add API documentation
- Configure Ruff for linting
- Update README with project information

README.md

@@ -1,3 +1,88 @@
-# FastAPI Application
+# FastAPI REST API Service
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+A fully-featured REST API service built with FastAPI and SQLite.
+
+## Features
+
+- RESTful API design
+- SQLite database with SQLAlchemy ORM
+- Database migrations with Alembic
+- Pydantic data validation
+- CRUD operations for items
+- Health check endpoint
+- API documentation with Swagger UI and ReDoc
+
+## Project Structure
+
+```
+.
+├── alembic.ini                 # Alembic configuration
+├── app                         # Main application package
+│   ├── api                     # API endpoints
+│   │   ├── api.py             # API router
+│   │   ├── deps.py            # API dependencies
+│   │   └── endpoints          # API endpoint modules
+│   │       └── items.py       # Items endpoints
+│   ├── core                    # Core modules
+│   │   └── config.py          # Application settings
+│   ├── crud                    # CRUD operations
+│   │   ├── base.py            # Base CRUD class
+│   │   └── crud_item.py       # Item CRUD operations
+│   ├── db                      # Database
+│   │   ├── base.py            # Import all models for Alembic
+│   │   ├── base_class.py      # Base model class
+│   │   ├── migrations         # Alembic migrations
+│   │   └── session.py         # Database session
+│   ├── models                  # SQLAlchemy models
+│   │   └── item.py            # Item model
+│   └── schemas                 # Pydantic schemas
+│       └── item.py            # Item schemas
+├── main.py                     # Application entry point
+├── pyproject.toml              # Ruff linting configuration
+└── requirements.txt            # Python dependencies
+```
+
+## Setup
+
+1. Clone the repository
+2. Install the dependencies:
+
+```bash
+pip install -r requirements.txt
+```
+
+3. Run the application:
+
+```bash
+uvicorn main:app --reload
+```
+
+## API Endpoints
+
+- **GET /api/v1/items**: Get all items
+- **POST /api/v1/items**: Create a new item
+- **GET /api/v1/items/{id}**: Get a specific item
+- **PUT /api/v1/items/{id}**: Update a specific item
+- **DELETE /api/v1/items/{id}**: Delete a specific item
+- **GET /health**: Health check endpoint
+
+## API Documentation
+
+API documentation is available at:
+
+- Swagger UI: `/docs`
+- ReDoc: `/redoc`
+
+## Database
+
+The application uses SQLite as the database:
+
+- Database location: `/app/storage/db/db.sqlite`
+- Database models are defined in the `app/models` directory
+- Database migrations are managed with Alembic in the `app/db/migrations` directory
+
+## Development
+
+- Code linting: `ruff check .`
+- Code formatting: `ruff format .`
+- Run migrations: `alembic upgrade head`

alembic.ini

@@ -0,0 +1,103 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = app/db/migrations
+
+# template used to generate migration files
+# file_template = %%(rev)s_%%(slug)s
+
+# sys.path path, will be prepended to sys.path if present.
+# defaults to the current working directory.
+prepend_sys_path = .
+
+# timezone to use when rendering the date within the migration file
+# as well as the filename.
+# If specified, requires the python-dateutil library that can be
+# installed by adding `alembic[tz]` to the pip requirements
+# 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 app/db/migrations/versions.  When using multiple version
+# directories, initial revisions must be specified with --version-path.
+# The path separator used here should be the separator specified by "version_path_separator" below.
+# version_locations = %(here)s/bar:%(here)s/bat:app/db/migrations/versions
+
+# version path separator; As mentioned above, this is the character used to split
+# version_locations. The default within new alembic.ini files is "os", which uses os.pathsep.
+# If this key is omitted entirely, it falls back to the legacy behavior of splitting on spaces and/or commas.
+# Valid values for version_path_separator are:
+#
+# version_path_separator = :
+# version_path_separator = ;
+# version_path_separator = space
+version_path_separator = os  # Use os.pathsep. Default configuration used for new projects.
+
+# the output encoding used when revision files
+# are written from script.py.mako
+# output_encoding = utf-8
+
+# SQLite URL - use absolute path
+sqlalchemy.url = sqlite:////app/storage/db/db.sqlite
+
+
+[post_write_hooks]
+# post_write_hooks defines scripts or Python functions that are run
+# on newly generated revision scripts.  See the documentation for further
+# detail and examples
+
+# format using "black" - use the console_scripts runner, against the "black" entrypoint
+# hooks = black
+# black.type = console_scripts
+# black.entrypoint = black
+# black.options = -l 79 REVISION_SCRIPT_FILENAME
+
+# 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/deps.py

@@ -0,0 +1,14 @@
+from typing import Generator
+
+from app.db.session import SessionLocal
+
+
+def get_db() -> Generator:
+    """
+    Dependency for getting the database session.
+    """
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()

app/api/endpoints/items.py

@@ -0,0 +1,97 @@
+from typing import Any, List, Optional
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+
+from app import crud
+from app.api.deps import get_db
+from app.schemas.item import Item, ItemCreate, ItemUpdate
+
+router = APIRouter()
+
+
+@router.get("/", response_model=List[Item])
+def read_items(
+    db: Session = Depends(get_db),
+    skip: int = 0,
+    limit: int = 100,
+    active: Optional[bool] = None,
+) -> Any:
+    """
+    Retrieve items.
+    """
+    if active is not None:
+        items = crud.item.get_multi_by_active(db, active=active, skip=skip, limit=limit)
+    else:
+        items = crud.item.get_multi(db, skip=skip, limit=limit)
+    return items
+
+
+@router.post("/", response_model=Item)
+def create_item(
+    *,
+    db: Session = Depends(get_db),
+    item_in: ItemCreate,
+) -> Any:
+    """
+    Create new item.
+    """
+    item = crud.item.create(db=db, obj_in=item_in)
+    return item
+
+
+@router.get("/{id}", response_model=Item)
+def read_item(
+    *,
+    db: Session = Depends(get_db),
+    id: int,
+) -> Any:
+    """
+    Get item by ID.
+    """
+    item = crud.item.get(db=db, id=id)
+    if not item:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Item not found",
+        )
+    return item
+
+
+@router.put("/{id}", response_model=Item)
+def update_item(
+    *,
+    db: Session = Depends(get_db),
+    id: int,
+    item_in: ItemUpdate,
+) -> Any:
+    """
+    Update an item.
+    """
+    item = crud.item.get(db=db, id=id)
+    if not item:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Item not found",
+        )
+    item = crud.item.update(db=db, db_obj=item, obj_in=item_in)
+    return item
+
+
+@router.delete("/{id}", response_model=Item)
+def delete_item(
+    *,
+    db: Session = Depends(get_db),
+    id: int,
+) -> Any:
+    """
+    Delete an item.
+    """
+    item = crud.item.get(db=db, id=id)
+    if not item:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Item not found",
+        )
+    item = crud.item.remove(db=db, id=id)
+    return item

app/core/config.py

@@ -0,0 +1,35 @@
+from pathlib import Path
+from typing import List, Union
+
+from pydantic import AnyHttpUrl, validator
+from pydantic_settings import BaseSettings
+
+
+class Settings(BaseSettings):
+    API_V1_STR: str = "/api/v1"
+    PROJECT_NAME: str = "REST API Service"
+    
+    # CORS configuration
+    BACKEND_CORS_ORIGINS: List[AnyHttpUrl] = []
+
+    @validator("BACKEND_CORS_ORIGINS", pre=True)
+    def assemble_cors_origins(cls, v: Union[str, List[str]]) -> Union[List[str], str]:
+        if isinstance(v, str) and not v.startswith("["):
+            return [i.strip() for i in v.split(",")]
+        elif isinstance(v, (list, str)):
+            return v
+        raise ValueError(v)
+
+    # Database
+    DB_DIR: Path = Path("/app") / "storage" / "db"
+    SQLALCHEMY_DATABASE_URL: str = f"sqlite:///{DB_DIR}/db.sqlite"
+    
+    class Config:
+        case_sensitive = True
+        env_file = ".env"
+
+
+settings = Settings()
+
+# Ensure the database directory exists
+settings.DB_DIR.mkdir(parents=True, exist_ok=True)

app/crud/__init__.py

@@ -0,0 +1 @@
+from app.crud.crud_item import item  # noqa

app/crud/base.py

@@ -0,0 +1,64 @@
+from typing import Any, Dict, Generic, List, Optional, Type, TypeVar, Union
+
+from fastapi.encoders import jsonable_encoder
+from pydantic import BaseModel
+from sqlalchemy.orm import Session
+
+from app.db.base_class import Base
+
+ModelType = TypeVar("ModelType", bound=Base)
+CreateSchemaType = TypeVar("CreateSchemaType", bound=BaseModel)
+UpdateSchemaType = TypeVar("UpdateSchemaType", bound=BaseModel)
+
+
+class CRUDBase(Generic[ModelType, CreateSchemaType, UpdateSchemaType]):
+    def __init__(self, model: Type[ModelType]):
+        """
+        CRUD object with default methods to Create, Read, Update, Delete (CRUD).
+        **Parameters**
+        * `model`: A SQLAlchemy model class
+        * `schema`: A Pydantic model (schema) class
+        """
+        self.model = model
+
+    def get(self, db: Session, id: Any) -> Optional[ModelType]:
+        return db.query(self.model).filter(self.model.id == id).first()
+
+    def get_multi(
+        self, db: Session, *, skip: int = 0, limit: int = 100
+    ) -> List[ModelType]:
+        return db.query(self.model).offset(skip).limit(limit).all()
+
+    def create(self, db: Session, *, obj_in: CreateSchemaType) -> ModelType:
+        obj_in_data = jsonable_encoder(obj_in)
+        db_obj = self.model(**obj_in_data)
+        db.add(db_obj)
+        db.commit()
+        db.refresh(db_obj)
+        return db_obj
+
+    def update(
+        self,
+        db: Session,
+        *,
+        db_obj: ModelType,
+        obj_in: Union[UpdateSchemaType, Dict[str, Any]]
+    ) -> ModelType:
+        obj_data = jsonable_encoder(db_obj)
+        if isinstance(obj_in, dict):
+            update_data = obj_in
+        else:
+            update_data = obj_in.model_dump(exclude_unset=True)
+        for field in obj_data:
+            if field in update_data:
+                setattr(db_obj, field, update_data[field])
+        db.add(db_obj)
+        db.commit()
+        db.refresh(db_obj)
+        return db_obj
+
+    def remove(self, db: Session, *, id: int) -> ModelType:
+        obj = db.query(self.model).get(id)
+        db.delete(obj)
+        db.commit()
+        return obj

app/crud/crud_item.py

@@ -0,0 +1,26 @@
+from typing import List, Optional
+
+from sqlalchemy.orm import Session
+
+from app.crud.base import CRUDBase
+from app.models.item import Item
+from app.schemas.item import ItemCreate, ItemUpdate
+
+
+class CRUDItem(CRUDBase[Item, ItemCreate, ItemUpdate]):
+    def get_by_title(self, db: Session, *, title: str) -> Optional[Item]:
+        return db.query(Item).filter(Item.title == title).first()
+
+    def get_multi_by_active(
+        self, db: Session, *, active: bool, skip: int = 0, limit: int = 100
+    ) -> List[Item]:
+        return (
+            db.query(Item)
+            .filter(Item.is_active == active)
+            .offset(skip)
+            .limit(limit)
+            .all()
+        )
+
+
+item = CRUDItem(Item)

app/db/base.py

@@ -0,0 +1,4 @@
+# Import all the models, so that Base has them before being
+# imported by Alembic
+from app.db.base_class import Base  # noqa
+from app.models.item import Item  # noqa

app/db/base_class.py

@@ -0,0 +1,14 @@
+from typing import Any
+
+from sqlalchemy.ext.declarative import as_declarative, declared_attr
+
+
+@as_declarative()
+class Base:
+    id: Any
+    __name__: str
+    
+    # Generate tablename automatically based on class name
+    @declared_attr
+    def __tablename__(cls) -> str:
+        return cls.__name__.lower()

app/db/migrations/env.py

@@ -0,0 +1,76 @@
+from logging.config import fileConfig
+
+from alembic import context
+from sqlalchemy import engine_from_config, pool
+
+from app.db.base import Base  # noqa
+
+# 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() -> 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.
+
+    """
+    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:
+    """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:
+        # Check if we're using SQLite to enable batch mode
+        is_sqlite = connection.dialect.name == "sqlite"
+        context.configure(
+            connection=connection,
+            target_metadata=target_metadata,
+            # Enable batch mode for SQLite to handle column alterations
+            render_as_batch=is_sqlite,
+        )
+
+        with context.begin_transaction():
+            context.run_migrations()

app/db/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() -> None:
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade() -> None:
+    ${downgrades if downgrades else "pass"}

app/db/migrations/versions/f4b99ba39dc1_create_items_table.py

@@ -0,0 +1,43 @@
+"""create items table
+
+Revision ID: f4b99ba39dc1
+Revises: 
+Create Date: 2023-07-01 00:00:00.000000
+
+"""
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = "f4b99ba39dc1"
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "item",
+        sa.Column("id", sa.Integer(), nullable=False),
+        sa.Column("title", sa.String(255), nullable=False, index=True),
+        sa.Column("description", sa.Text(), nullable=True),
+        sa.Column("is_active", sa.Boolean(), default=True),
+        sa.Column(
+            "created_at",
+            sa.DateTime(timezone=True),
+            server_default=sa.text("(CURRENT_TIMESTAMP)"),
+        ),
+        sa.Column(
+            "updated_at",
+            sa.DateTime(timezone=True),
+            server_default=sa.text("(CURRENT_TIMESTAMP)"),
+            onupdate=sa.text("(CURRENT_TIMESTAMP)"),
+        ),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_index(op.f("ix_item_id"), "item", ["id"], unique=False)
+
+
+def downgrade() -> None:
+    op.drop_index(op.f("ix_item_id"), table_name="item")
+    op.drop_table("item")

app/db/session.py

@@ -0,0 +1,26 @@
+from sqlalchemy import create_engine
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import sessionmaker
+
+from app.core.config import settings
+
+# Create SQLite engine
+engine = create_engine(
+    settings.SQLALCHEMY_DATABASE_URL,
+    connect_args={"check_same_thread": False}  # SQLite specific argument
+)
+
+# Create sessionmaker for database sessions
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+# Create a base class for SQLAlchemy models
+Base = declarative_base()
+
+
+# Dependency to get DB session
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()

app/models/item.py

@@ -0,0 +1,20 @@
+from sqlalchemy import Boolean, Column, DateTime, Integer, String, Text
+from sqlalchemy.sql import func
+
+from app.db.base_class import Base
+
+
+class Item(Base):
+    """
+    Item model for storing item data
+    """
+    id = Column(Integer, primary_key=True, index=True)
+    title = Column(String(255), nullable=False, index=True)
+    description = Column(Text, nullable=True)
+    is_active = Column(Boolean, default=True)
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(
+        DateTime(timezone=True),
+        server_default=func.now(),
+        onupdate=func.now(),
+    )

app/schemas/item.py

@@ -0,0 +1,42 @@
+from datetime import datetime
+from typing import Optional
+
+from pydantic import BaseModel, Field
+
+
+# Shared properties
+class ItemBase(BaseModel):
+    title: str = Field(..., title="Item title", max_length=255)
+    description: Optional[str] = Field(None, title="Item description")
+    is_active: Optional[bool] = Field(True, title="Item is active")
+
+
+# Properties to receive on item creation
+class ItemCreate(ItemBase):
+    pass
+
+
+# Properties to receive on item update
+class ItemUpdate(ItemBase):
+    title: Optional[str] = Field(None, title="Item title", max_length=255)
+    is_active: Optional[bool] = Field(None, title="Item is active")
+
+
+# Properties shared by models returned from API
+class ItemInDBBase(ItemBase):
+    id: int
+    created_at: datetime
+    updated_at: datetime
+
+    class Config:
+        from_attributes = True
+
+
+# Properties to return to client
+class Item(ItemInDBBase):
+    pass
+
+
+# Properties stored in DB
+class ItemInDB(ItemInDBBase):
+    pass

main.py

@@ -0,0 +1,32 @@
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+
+from app.api.api import api_router
+from app.core.config import settings
+
+app = FastAPI(
+    title=settings.PROJECT_NAME,
+    openapi_url=f"{settings.API_V1_STR}/openapi.json",
+    description="REST API Service",
+    version="0.1.0",
+)
+
+# Set all CORS enabled origins
+if settings.BACKEND_CORS_ORIGINS:
+    app.add_middleware(
+        CORSMiddleware,
+        allow_origins=[str(origin) for origin in settings.BACKEND_CORS_ORIGINS],
+        allow_credentials=True,
+        allow_methods=["*"],
+        allow_headers=["*"],
+    )
+
+app.include_router(api_router, prefix=settings.API_V1_STR)
+
+
+@app.get("/health", tags=["Health"])
+def health_check():
+    """
+    Health check endpoint to verify service is running
+    """
+    return {"status": "healthy"}

pyproject.toml

@@ -0,0 +1,36 @@
+[tool.ruff]
+# A specific subset of all checks is enabled, as per specific needs.
+line-length = 88
+target-version = "py310"
+
+[tool.ruff.lint]
+# Enable flake8-bugbear (`B`) rules.
+select = ["E", "F", "B", "I"]
+
+# Exclude a variety of commonly ignored directories.
+exclude = [
+    ".git",
+    ".github",
+    ".venv",
+    "venv",
+    ".env",
+    "env",
+    "__pycache__",
+    ".mypy_cache",
+    ".pytest_cache",
+]
+
+# Allow unused variables when underscore-prefixed.
+dummy-variable-rgx = "^(_+|(_+[a-zA-Z0-9_]*[a-zA-Z0-9]+?))$"
+
+[tool.ruff.lint.mccabe]
+# Unlike Flake8, default to a complexity level of 10.
+max-complexity = 10
+
+[tool.ruff.lint.isort]
+known-third-party = ["fastapi", "pydantic", "sqlalchemy", "alembic"]
+
+[tool.ruff.lint.per-file-ignores]
+"__init__.py" = ["F401"]  # Ignore unused imports in __init__ files
+"app/api/deps.py" = ["B008"]  # Ignore function calls in default arguments (common in FastAPI)
+"app/api/endpoints/*.py" = ["B008"]  # Ignore function calls in default arguments for endpoints

requirements.txt

@@ -0,0 +1,9 @@
+fastapi>=0.95.0
+uvicorn>=0.21.1
+pydantic>=2.0.0
+sqlalchemy>=2.0.0
+alembic>=1.10.0
+python-dotenv>=1.0.0
+ruff>=0.0.265
+python-multipart>=0.0.6
+pydantic-settings>=2.0.0