Middlewares and nested applications

[olexandr-klymenko]

Long story short

There is no clear notion about how middlewares should work in nested applications.
By common sense if middleware is mentioned in sub application it shouldn't be invoked for root application. But as the matter of fact it doesn't work the I expected. Every middleware is applied for every endpoint which is a bit wierd.

Expected behaviour

middlewares used for declare sub application shouldn't be invoked when root application enpoint is requested

Actual behaviour

every middleware is applied for every ebdpoint

Steps to reproduce

1. Create root application
2. Create route in root application
3. Create sub app with middlewares
4. Attach sub app to root application
5. Request root application endpoint

Your environment

python 3.6.3, aiohttp 2.3.1

[asvetlov]

Middlewares are nested too.
If endpoints is handled by subapp -- middlewares from main app will be applied first, than subapp middlewares.

[olexandr-klymenko]

I mean this is true the other way around as well. A middleware from sub app affects on root application

[asvetlov]

Hmm. If it's true -- this is a regression and behavior should be fixed.

[asvetlov]

Steps to reproduce:

A sub application is not working and it is not very convenient.

from aiohttp import web

async def index(request):
    print('*'*8, request.path, '*'*8)
    print('Index!')
    return web.Response(body=b'Index', content_type='text/plain')


async def login(request):
    print('*' * 8, request.path, '*' * 8)
    print('Login!')
    return web.Response(body=b'Login', content_type='text/plain')

async def cabinet(request):
    print('*' * 8, request.path, '*' * 8)
    print('Cabinet!')
    return web.Response(body=b'Cabinet', content_type='text/plain')


@web.middleware
async def auth_middleware(request, handler):
    print('m' * 8, request.path, 'm' * 8)
    print('Auth middleware!')
    return await handler(request)


root_app = web.Application()
admin_app = web.Application(
    middlewares=[auth_middleware],
)
admin_login_app = web.Application()

root_app.router.add_get('/', index, name='index')
admin_app.router.add_get('/cabinet/', cabinet, name='admin:cabinet')
admin_login_app.router.add_route('*', '/', login, name='login')

admin_app.add_subapp('/login', admin_login_app)
root_app.add_subapp('/admin/', admin_app)


web.run_app(root_app)

$ python server.py 
======== Running on http://0.0.0.0:8080 ========
(Press CTRL+C to quit)
******** / ********
Index!
mmmmmmmm /admin/login/ mmmmmmmm
Auth middleware!
******** /admin/login/ ********
Login!
mmmmmmmm /admin/cabinet/ mmmmmmmm
Auth middleware!
******** /admin/cabinet/ ********
Cabinet!

[asvetlov]

The issue is wrong.
There are two subapplications:

1. For handling /admin/* requests
2. Nested app for handling /admin/cabinet/

Obviously /admin/cabinet/ request is passed to subapp 1 (with its middlweares) and after that to nested subapp 2.

Everything is working as expected.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a [new issue] for related bugs.
If you feel like there's important points made in this discussion, please include those exceprts into that [new issue].
[new issue]: https://github.com/aio-libs/aiohttp/issues/new