我想为我的端点添加一个
auth_required
装饰器。
(请考虑这个问题是关于装饰器的,而不是中间件)
所以一个简单的装饰器看起来像这样:
def auth_required(func):
def wrapper(*args, **kwargs):
if user_ctx.get() is None:
raise HTTPException(...)
return func(*args, **kwargs)
return wrapper
所以有2种用法:
@auth_required
@router.post(...)
或
@router.post(...)
@auth_required
第一种方法不起作用,因为
router.post
创建了一个路由器,该路由器保存到 APIRouter 对象的 self.routes
中。第二种方法不起作用,因为它无法验证 pydantic 对象。对于任何请求模型,它说missing args, missing kwargs
.
所以我的问题是——如何向 FastAPI 端点添加装饰器?我应该进入
router.routes
并修改现有端点吗?或者使用一些functools.wraps
之类的功能?
如何向 FastAPI 端点添加装饰器?
@functools.wraps(...)
--(PyDoc)装饰器作为,
from functools import wraps
from fastapi import FastAPI
from pydantic import BaseModel
class SampleModel(BaseModel):
name: str
age: int
app = FastAPI()
def auth_required(func):
@wraps(func)
async def wrapper(*args, **kwargs):
return await func(*args, **kwargs)
return wrapper
@app.post("/")
@auth_required # Custom decorator
async def root(payload: SampleModel):
return {"message": "Hello World", "payload": payload}
此方法的主要警告是您无法访问包装器中的
request
对象,我认为这是您的主要意图。
如果需要访问请求,必须将参数添加到路由器函数中,
from fastapi import Request
@app.post("/")
@auth_required # Custom decorator
async def root(request: Request, payload: SampleModel):
return {"message": "Hello World", "payload": payload}
我不确定FastAPI中间件有什么问题,毕竟
@app.middleware(...)
也是一个装饰器。
以下是如何使用装饰器向路由处理程序添加额外参数:
from fastapi import FastAPI, Request
from pydantic import BaseModel
class SampleModel(BaseModel):
name: str
age: int
app = FastAPI()
def do_something_with_request_object(request: Request):
print(request)
def auth_required(handler):
async def wrapper(request: Request, *args, **kwargs):
do_something_with_request_object(request)
return await handler(*args, **kwargs)
# Fix signature of wrapper
import inspect
wrapper.__signature__ = inspect.Signature(
parameters = [
# Use all parameters from handler
*inspect.signature(handler).parameters.values(),
# Skip *args and **kwargs from wrapper parameters:
*filter(
lambda p: p.kind not in (inspect.Parameter.VAR_POSITIONAL, inspect.Parameter.VAR_KEYWORD),
inspect.signature(wrapper).parameters.values()
)
],
return_annotation = inspect.signature(handler).return_annotation,
)
return wrapper
@app.post("/")
@auth_required # Custom decorator
async def root(payload: SampleModel):
return {"message": f"Hello {payload.name}, {payload.age} years old!"}
只需在路径操作装饰器中使用dependencies:
from fastapi import Depends, FastAPI, Header, HTTPException
app = FastAPI()
async def verify_token(x_token: str = Header()):
if x_token != "fake-super-secret-token":
raise HTTPException(status_code=400, detail="X-Token header invalid")
async def verify_key(x_key: str = Header()):
if x_key != "fake-super-secret-key":
raise HTTPException(status_code=400, detail="X-Key header invalid")
return x_key
@app.get("/items/", dependencies=[Depends(verify_token), Depends(verify_key)])
async def read_items():
return [{"item": "Foo"}, {"item": "Bar"}]
除了 JPG 的答案,您还可以使用
Request
访问装饰器中的 kwargs.get('request')
对象。一个完整的装饰器看起来像:
def render_template(template):
"""decorator to render a template with a context"""
def decorator(func):
@wraps(func)
def wrapper(*args, **kwargs):
# access request object
request = kwargs.get('request')
context = func(*args, **kwargs)
if context is None:
context = {}
return templates.TemplateResponse(template, {**context, 'request': request})
return wrapper
return decorator
装饰函数需要将
Request
作为参数。