base href for swagger spec and ui

[eterna2]

Is your feature request related to a problem? Please describe.
Our fastapi service is place behind a proxy using path-based routing - i.e. /docs becames /foo/docs

This result in the default swagger spec as well as the swagger UI to fails as the openapi path passed to the html is an absolute ref (i.e. /docs or /prefix/docs) which will resolve incorrectly if there is a non-fastapi path routing.

See

fastapi/fastapi/applications.py

Line 91 in fc7d123

openapi_url = self.openapi_prefix + self.openapi_url

Describe the solution you'd like
Either incorporate a base href argument to fast API, or set the openapi_url to relative ref (i.e. ./docs or ./prefix/docs).

Similar fix should be done for the openapi spec generation.

I would prefer the former solution as it will also correctly generate the openapi spec (to include the non-fastapi prefix).

Describe alternatives you've considered
Currently I provision my own custom route with the modified swagger UI HTML as well as the openapi spec.

[eterna2]

I can probably do a PR if it can expedite this feature request.

[euri10]

isn;t that a job for uvicorn root_path ?

…

On Tue, Sep 17, 2019 at 5:42 PM Eterna2 ***@***.***> wrote: I can probably do a PR if it can expedite this feature request. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#544?email_source=notifications&email_token=AAINSPQYUJEPCWP467BRWWDQKD3E5A5CNFSM4IXR23U2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD6464NY#issuecomment-532278839>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAINSPV2346IBQPZUGZN2VTQKD3E5ANCNFSM4IXR23UQ> .

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[eterna2]

Ah. I didn't realise there is this option.

Thanks. Problem solved.

[eterna2]

Reopening this issue for more clarity.

My service is deployed in kubernetes and API gateway is serviced with ambassador. The path prefix is serviced by ambassador not by uvicorn.

I am routing ambassador /foo/api to /api in uvicorn which will result in this issue. But I probably can workaround this by setting the route the same both in ambassador and in uvicorn

i.e. route ambassador /foo/api to /foo/api in uvicorn.

Let me try tomorrow and I will close this issue if it works.

[tiangolo]

Thanks for the help here @euri10 ! 👏 🙇

Thanks for reporting back and closing the issue @eterna2 👍

[tiangolo]

Just for completeness, #1199 added support for root_path, and there are new docs for running behind a proxy here: https://fastapi.tiangolo.com/advanced/behind-a-proxy/

It's available in FastAPI 0.56.0.

[MatthewScholefield]

To summarize, now you can just pass root_path='/api/v1' to FastAPI(...). One thing to note, I realized I was having issues with authorization because I was using tokenUrl="/token" instead of tokenUrl="token" in OAuth2PasswordBearer(...).

[github-actions]

Assuming the original need was handled, this will be automatically closed now. But feel free to add more comments or create new issues or PRs.