Fix root on gradio mounted apps

[aliabid94]

When gradio apps are mounted on fastapi and theres a reverse proxy, the root was not correctly pointing to the mounted path of the fastapi app. Fixed now. Fixes: #8073

Test by adding this nginx config:

    server {
        server_name localhost;
        listen 18000;

        location / {
                proxy_pass http://127.0.0.1:8000/;
                proxy_buffering off;
                proxy_redirect off;
                proxy_http_version 1.1;
                proxy_set_header Upgrade $http_upgrade;
                proxy_set_header Connection "upgrade";
                proxy_set_header Host 'localhost:18000';
                proxy_set_header X-Forwarded-Host 'localhost:18000';
                proxy_set_header X-Forwarded-Proto $scheme;

        }
    }

and this app:

import gradio as gr

def greet(name):
    return "Hello " + name + "!"


with gr.Blocks() as demo:
    name = gr.Textbox(label="Name")
    output = gr.Textbox(label="Output Box")
    greet_btn = gr.Button("Greet")
    greet_btn.click(fn=greet, inputs=name, outputs=output, api_name="greet")

from fastapi import FastAPI
app = FastAPI()

gr.mount_gradio_app(app, demo, path="/gradio")

# run app
import uvicorn
uvicorn.run(app)

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Fix root on gradio mounted apps

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[freddyaboulton]

Just verified the fix nice @aliabid94 ! I think we can remove the print?

[abidlabs]

Any way we could add a test for this?

[aliabid94]

Any way we could add a test for this?

There needs to be an nginx setup for reverse proxying, which would be pretty hard :/

[freddyaboulton]

An idea: We can host a space in the gradio-test org that is an app behind nginx and then we have a flaky unit test that ensures the events work (and maybe that the css is properly loaded) by calling via the client/requests module.

But I don't think we should do this until we fix most of the "cloud" related issues and can come up with the most representative "test cases"

[abidlabs]

I like that, and perhaps we can also write a simpler unit test that runs locally that "simulates" an nginx reverse proxy using two FastAPI apps. The idea would be to have:

• FastAPI app 1 running on port 8000, accepts all inbound network requests and then attaches a X-Forwarded-Host header, and then forwards them to a localhost:8001/gradio
• FastAPI app 2 running on port 8001 which has a mounted Gradio app at /gradio. This FastAPI app should explicitly reject all inbound connections that don't have a X-Forwarded-Host. So only connections that come through FastAPI app 1 should pass through to FastAPI app 2.

Then we basically see if we can make requests to localhost:8000 and see if they get completed successfully

[abidlabs]

Ok with merging this for now though and like @freddyaboulton said, we can add the tests once we've fixed more cloud issues.