Installation

• fastapi

  python -m pip install fastapi
  

• uvicorn # fastapi使用uvicorn

  python -m pip install uvicorn
  

• 若有上傳檔案，則需下載額外套件

  python -m pip install python-multipart
  

---

How to use fastapi

• Main
  主要執行程式
  ex: main.py

• Schema 定義輸入參數
  ex: schema.py

• Controller
  用於製作API設置
  ex: controller.py

• Service
  主要計算邏輯
  ex: service.py

• Middleware

  • 全域中間層 用於做系統層面卡控
    ex: middleware.py
  • 單個模塊中間層邏輯
    用於做各服務層面卡控
    ex: filter.py
    ! 注意：若要Catch message，需抓取HTTPException

    try:
        filter_controller()
    except HTTPException as err:
        error_code = err.status_code # 400
        msg = err.detail # 未輸入參數

    Controller套用設置

    from fastapi import Depends
    from fastapi.router import APIRouter
    api = APIRouter()
    
    @api.post('/middleTest')
    def middle_test(
        dependencies=[
            Depends(controller_middleware),
        ]
    ):
    ...

• Env

  直接設置環境變數

    ```
    # CMD
    set test=test
    ```
  

  讀取環境變數檔案

  1. 下載相依套件

     python -m pip install python-dotenv
     

  2. 新增.env檔案 config.env

     test="TESTENV"
     

  3. Uvicorn CMD執行時命令
     1. 方法1

        uvicorn --env-file="config.env"
        

     2. 方法2

        uvicorn.run('testapp:app', env_file='config.env')

  4. config.py

     from pydantic import BaseSetting
     
     class Setting(BaseSetting):
         test:str
     print(Setting().test) # TESTENV

使用Request傳輸自定義變數(全域)

from fastapi import Request

def tansport(func)
    def wrapper(request:Request)
        request.state.id = '123'
        return func(request)
    return wrapper

Swagger 設立 Token驗證

• main.py

from fastapi import FastAPI, Security, Depends
from fastapi.security import APIKeyHeader+

async def CheckHeader(
    token_key:str=Security(APIKeyHeader(name='Authorization'))
):
    return token_key

app = FastAPI(
    title='test',
    dependencies=[Depends(CheckHeader)]
)

lifespan 設置

from fastapi import FastAPI
from contextlib import asynccontextmanager

@asynccontextmanager
async def lifespan(app:FastAPI):
    do something...
    yield
    end do something...

app = FastAPI(lifespan=lifespan)

Gunicorn

• Gunicorn CMD執行時命令(Windows不適用)

  # 官方文件設置
  gunicorn mainapp:app --worker 4 --worker-class uvicorn.workers.UvicornWorker --bind 0.0.0.0:8888
  

• Gunicorn Config設定
  gunicorn.conf.py

大架構使用案例

• fastapi + SQLalchemy
  參閱 Reserve專案(限本人)