Create REST API with FastAPI and SQLite

- Set up project structure with FastAPI
- Configure SQLite database with SQLAlchemy
- Set up Alembic for migrations
- Create Item model and schema
- Implement CRUD operations
- Add health endpoint

generated with BackendIM... (backend.im)

README.md

@@ -1,3 +1,87 @@
-# FastAPI Application
+# Generic REST API Service
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+A RESTful API service built with FastAPI and SQLite database.
+
+## Features
+
+- FastAPI framework with automatic Swagger/ReDoc documentation
+- SQLAlchemy ORM for database management
+- Alembic for database migrations
+- SQLite database
+- Pydantic models for data validation
+- CRUD operations for resources
+- Health check endpoint
+
+## Project Structure
+
+```
+.
+├── alembic/                 # Database migration scripts
+├── app/                     # Application code
+│   ├── api/                 # API endpoints
+│   │   └── v1/              # API version 1
+│   ├── core/                # Core functionality
+│   ├── crud/                # CRUD operations
+│   ├── db/                  # Database setup
+│   ├── models/              # SQLAlchemy models
+│   └── schemas/             # Pydantic schemas
+├── alembic.ini              # Alembic configuration
+├── main.py                  # Application entry point
+└── requirements.txt         # Project dependencies
+```
+
+## Installation
+
+1. Clone the repository:
+
+```bash
+git clone <repository-url>
+cd genericrestapiservice
+```
+
+2. Create a virtual environment:
+
+```bash
+python -m venv venv
+source venv/bin/activate  # On Windows: venv\Scripts\activate
+```
+
+3. Install dependencies:
+
+```bash
+pip install -r requirements.txt
+```
+
+4. Run database migrations:
+
+```bash
+alembic upgrade head
+```
+
+## Running the Application
+
+Start the application using Uvicorn:
+
+```bash
+uvicorn main:app --reload
+```
+
+The API will be available at http://localhost:8000
+
+Documentation is available at:
+- Swagger UI: http://localhost:8000/docs
+- ReDoc: http://localhost:8000/redoc
+
+## API Endpoints
+
+### Health Check
+
+- `GET /api/v1/health`: Check API health
+
+### Items Resource
+
+- `GET /api/v1/items`: List 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 an item
+- `DELETE /api/v1/items/{id}`: Delete an item

alembic.ini

@@ -0,0 +1,86 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = alembic
+
+# 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
+
+# SQLite URL with 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
+
+# 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

alembic/env.py

@@ -0,0 +1,81 @@
+import os
+import sys
+from logging.config import fileConfig
+
+from sqlalchemy import engine_from_config
+from sqlalchemy import pool
+
+from alembic import context
+
+# this is the Alembic Config object, which provides
+# access to the values within the .ini file in use.
+config = context.config
+
+# Add the parent directory to python path
+sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+# 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 app.db.base import Base
+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:
+        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():
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade():
+    ${downgrades if downgrades else "pass"}

alembic/versions/001_create_items_table.py

@@ -0,0 +1,37 @@
+"""create items table
+
+Revision ID: 001
+Revises: 
+Create Date: 2025-05-13
+
+"""
+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():
+    op.create_table(
+        'item',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('title', sa.String(length=255), nullable=False),
+        sa.Column('description', sa.Text(), nullable=True),
+        sa.Column('is_active', sa.Boolean(), default=True),
+        sa.Column('created_at', sa.DateTime(), default=sa.func.now()),
+        sa.Column('updated_at', sa.DateTime(), default=sa.func.now(), onupdate=sa.func.now()),
+        sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_item_id'), 'item', ['id'], unique=False)
+    op.create_index(op.f('ix_item_title'), 'item', ['title'], unique=False)
+
+
+def downgrade():
+    op.drop_index(op.f('ix_item_title'), table_name='item')
+    op.drop_index(op.f('ix_item_id'), table_name='item')
+    op.drop_table('item')

app/api/deps.py

@@ -0,0 +1,6 @@
+from typing import Generator
+
+from fastapi import Depends
+from sqlalchemy.orm import Session
+
+from app.db.session import get_db

app/api/routes.py

@@ -0,0 +1,7 @@
+from fastapi import APIRouter
+
+from app.api.v1 import health, items
+
+api_router = APIRouter()
+api_router.include_router(health.router, prefix="/health", tags=["health"])
+api_router.include_router(items.router, prefix="/items", tags=["items"])

app/api/v1/health.py

@@ -0,0 +1,28 @@
+from typing import Dict
+
+from fastapi import APIRouter, Depends
+from sqlalchemy.orm import Session
+
+from app.api import deps
+from app.db.session import engine
+
+router = APIRouter()
+
+
+@router.get("/", response_model=Dict[str, str])
+def health_check(db: Session = Depends(deps.get_db)) -> Dict[str, str]:
+    """
+    Health check endpoint to verify API is running and database connection is working.
+    """
+    try:
+        # Test database connection
+        with engine.connect() as connection:
+            connection.execute("SELECT 1")
+        db_status = "healthy"
+    except Exception:
+        db_status = "unhealthy"
+
+    return {
+        "status": "up",
+        "database": db_status
+    }

app/api/v1/items.py

@@ -0,0 +1,97 @@
+from typing import Any, List
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+
+from app import crud, schemas
+from app.api import deps
+from app.crud.crud_item import item
+
+router = APIRouter()
+
+
+@router.get("/", response_model=List[schemas.item.Item])
+def read_items(
+    db: Session = Depends(deps.get_db),
+    skip: int = 0,
+    limit: int = 100,
+    active_only: bool = False,
+) -> Any:
+    """
+    Retrieve items.
+    """
+    if active_only:
+        items = item.get_active_items(db, skip=skip, limit=limit)
+    else:
+        items = item.get_multi(db, skip=skip, limit=limit)
+    return items
+
+
+@router.post("/", response_model=schemas.item.Item, status_code=status.HTTP_201_CREATED)
+def create_item(
+    *,
+    db: Session = Depends(deps.get_db),
+    item_in: schemas.item.ItemCreate,
+) -> Any:
+    """
+    Create new item.
+    """
+    item_obj = item.create(db=db, obj_in=item_in)
+    return item_obj
+
+
+@router.get("/{id}", response_model=schemas.item.Item)
+def read_item(
+    *,
+    db: Session = Depends(deps.get_db),
+    id: int,
+) -> Any:
+    """
+    Get item by ID.
+    """
+    item_obj = item.get(db=db, id=id)
+    if not item_obj:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Item not found",
+        )
+    return item_obj
+
+
+@router.put("/{id}", response_model=schemas.item.Item)
+def update_item(
+    *,
+    db: Session = Depends(deps.get_db),
+    id: int,
+    item_in: schemas.item.ItemUpdate,
+) -> Any:
+    """
+    Update an item.
+    """
+    item_obj = item.get(db=db, id=id)
+    if not item_obj:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Item not found",
+        )
+    item_obj = item.update(db=db, db_obj=item_obj, obj_in=item_in)
+    return item_obj
+
+
+@router.delete("/{id}", response_model=schemas.item.Item)
+def delete_item(
+    *,
+    db: Session = Depends(deps.get_db),
+    id: int,
+) -> Any:
+    """
+    Delete an item.
+    """
+    item_obj = item.get(db=db, id=id)
+    if not item_obj:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Item not found",
+        )
+    item_obj = item.remove(db=db, id=id)
+    return item_obj

app/core/config.py

@@ -0,0 +1,28 @@
+from typing import List, Union
+from pydantic import AnyHttpUrl, validator
+from pydantic_settings import BaseSettings
+from pathlib import Path
+
+
+class Settings(BaseSettings):
+    API_V1_STR: str = "/api/v1"
+    PROJECT_NAME: str = "Generic 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 configuration
+    DB_DIR = Path("/app") / "storage" / "db"
+    DB_DIR.mkdir(parents=True, exist_ok=True)
+    SQLALCHEMY_DATABASE_URL: str = f"sqlite:///{DB_DIR}/db.sqlite"
+
+
+settings = Settings()

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 +1,20 @@
+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_active_items(
+        self, db: Session, *, skip: int = 0, limit: int = 100
+    ) -> List[Item]:
+        return db.query(Item).filter(Item.is_active == True).offset(skip).limit(limit).all()
+
+
+item = CRUDItem(Item)

app/db/base.py

@@ -0,0 +1,3 @@
+# Import all the models here, so that Alembic can auto-discover them
+from app.db.base_class import Base
+from app.models.item import Item  # noqa

app/db/base_class.py

@@ -0,0 +1,13 @@
+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/session.py

@@ -0,0 +1,22 @@
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker
+
+from app.core.config import settings
+
+# Create SQLAlchemy engine
+engine = create_engine(
+    settings.SQLALCHEMY_DATABASE_URL,
+    connect_args={"check_same_thread": False}  # only needed for SQLite
+)
+
+# Create SessionLocal class for database sessions
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+
+# Dependency for database sessions
+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, Boolean, DateTime
+from sqlalchemy.sql import func
+
+from app.db.base_class import Base
+
+
+class Item(Base):
+    id = Column(Integer, primary_key=True, index=True)
+    title = Column(String(255), index=True)
+    description = Column(Text, nullable=True)
+    is_active = Column(Boolean, default=True)
+    created_at = Column(DateTime, default=func.now())
+    updated_at = Column(DateTime, default=func.now(), onupdate=func.now())

app/schemas/item.py

@@ -0,0 +1,37 @@
+from datetime import datetime
+from typing import Optional
+
+from pydantic import BaseModel
+
+
+# Shared properties
+class ItemBase(BaseModel):
+    title: str
+    description: Optional[str] = None
+    is_active: bool = True
+
+
+# Properties to receive on item creation
+class ItemCreate(ItemBase):
+    pass
+
+
+# Properties to receive on item update
+class ItemUpdate(ItemBase):
+    title: Optional[str] = None
+    is_active: Optional[bool] = None
+
+
+# Properties shared by models stored in DB
+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

main.py

@@ -0,0 +1,30 @@
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+
+from app.api.routes import api_router
+from app.core.config import settings
+
+app = FastAPI(
+    title=settings.PROJECT_NAME,
+    description="Generic REST API Service",
+    version="0.1.0",
+    openapi_url=f"{settings.API_V1_STR}/openapi.json",
+    docs_url="/docs",
+    redoc_url="/redoc",
+)
+
+# 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)
+
+if __name__ == "__main__":
+    import uvicorn
+    uvicorn.run("main:app", host="0.0.0.0", port=8000, reload=True)

requirements.txt

@@ -0,0 +1,7 @@
+fastapi==0.110.0
+uvicorn==0.27.1
+sqlalchemy==2.0.28
+alembic==1.13.1
+pydantic==2.6.1
+pydantic-settings==2.2.1
+typing-extensions==4.9.0