Trouble connecting to localhost from browser using WSL

Question

I am trying to develop a Python FastAPI endpoint on Windows in a Ubuntu WSL environment but seem to be unable to view/access this from my browser. The weird thing is that I tried this a few days ago and it seemed to work fine but hasn't worked since as I seem to get this error from using curl in my powershell:

curl : Unable to connect to the remote server
At line:1 char:1
+ curl http://127.0.0.1:8000/
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (System.Net.HttpWebRequest:HttpWebRequest) [Invoke-WebRequest], WebException
    + FullyQualifiedErrorId : WebCmdletWebResponseException,Microsoft.PowerShell.Commands.InvokeWebRequestCommand

And in any browser I get an error where it can't find that server.

Here's some example code:

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
async def root():
    return {
        "message": "Hello World"
    }

and then I run uvicorn main:app --reload to start the app and try to access the endpoint provided.

My OS build version is 19041.508 if that matters.

Does anyone know how I can get this working again? I have no idea what could be going wrong here.

Thanks

Answer 1

Restarting the computer can sometimes fix odd connection issues. I'm not sure why. I was having trouble with a fastapi server refusing a secure connection, which previously worked and worked with curl but not in the browser, despite all sorts of measures. It mysteriously would refuse any connection from a browser. Restarted the computer and updated VS Code and everything seems to be working fine now. Maybe it was the VS Code update.