set root-path to uvicorn

[0anton]

I'm trying to set root_path to uvicorn as suggested [1] using this image, but don't see any options to pass arguments:

uvicorn main:app --root-path /api/v1

How can I do it?

Refs:

1. https://fastapi.tiangolo.com/advanced/behind-a-proxy/#providing-the-root_path

[poppash]

I struggled with this as well. Got it working in the end, albeit by setting root_path via the FastAPI object, e.g., app = FastAPI(root_path='/api/v1') and upgrading FastAPI.

Before upgrading it didn't work either using the current tiangolo/uvicorn-gunicorn-fastapi-docker:python3.8 image because it still has fastapi==0.55.1 installed. Try docker container run tiangolo/uvicorn-gunicorn-fastapi:python3.8 pip freeze | grep fastapi to verify. This image was last updated 3 months ago, probably just before the release of fastapi==0.56.0 (see PR).

Extending from tiangolo/uvicorn-gunicorn-fastapi-docker:python3.8 and then pip install --upgrade fastapi==0.61.1 did the trick for me.

@tiangolo will the images be updated in the near future?

[mindej]

@poppash
On my side it does not work I am getting an error in OpenApi

Python 3.7.8
fastapi 0.63.0

Run configuration:
uvicorn.run("app:app", host="0.0.0.0", port=port, reload=True)

I think the error is in the path here is console log:
127.0.0.1:54913 - "GET /api/v1/api/v1/openapi.json HTTP/1.1" 404 Not Found
Here is double path: /api/v1/api/v1/

[csib]

Gunicorn 20.1.0
fastapi 0.66.0

You can fix it with:
app = FastAPI(root_path=os.environ.get('ROOT_PATH'))

In this case you can change the ROOT_PATH with environment variable.

After that you can strip the ROOT_PATH within the proxy.

Example:
ROOT_PATH = /auth/v1

Remove the /auth/v1 from the endpoints.
@app.get("/create_token", tags=["User"]) -> Do no start it with /auth/v1 because it is added automatically

On the proxy you can strip it with:

apiVersion: traefik.containo.us/v1alpha1
kind: Middleware
metadata:
  name: strip-auth-v1-from-path
spec:
  stripPrefix:
    prefixes:
      - /auth/v1

After that it must work properly.

I also struggled for hours by the way. Tried the class ConfigurableWorker(UvicornWorker) method and struggled hours with the Gunicorn config but nothing worked. The solution above worked perfectly.

[Veldrovive]

For anybody coming here from the new ngrix-proxy version where the VIRTUAL_PATH option was introduced, this solution is very easy to set up. Just use app = FastAPI(root_path=os.environ.get('VIRTUAL_PATH')) and that will set your root correctly.

[devraj]

@0anton I came across this ticket while researching how to do this in gunicorn and passing --root-path=/api as so works for uvicorn

here's an excerpt from our docker-compose file:

command: ["uvicorn", "${PROJ_NAME}.api:app", "--host=0.0.0.0", "--port=80", "--root-path=/api", "--reload"]

I am in the process of documenting this property if it's of interest to anybody.

[shouryade]

@devraj Thank you so much!
This really helped me, as I didn't want to scaffold root_path in the application itself, since I was using nginx as a reverse proxy in production with docker-compose.
Thanks a ton!

For people using nginx as a reverse proxy, and stuck on how to forward the traffic to the right container, this is my current configuration:

server {
    listen 80;
    server_name example.com;
    location / {
        # For my react frontend served by an nginx container
        proxy_pass http://localhost:7000;

    }
    location /api/{
       # For FastAPI app running in docker container, where the endpoint should be /api/
       # notice the trailing slash at the end, it is important,so that it performs stripping properly. 
    	proxy_pass http://localhost:8100/;
  }
}

@tiangolo, if it is required, I could add a section for nginx here in the documentation.

[tiangolo]

Now that Uvicorn supports managing workers with --workers, including restarting dead ones, there's no need for Gunicorn. That also means that it's much simpler to build a Docker image from scratch now, I updated the docs to explain it.

Because of that, I deprecated this Docker image: https://github.com/tiangolo/uvicorn-gunicorn-fastapi-docker#-warning-you-probably-dont-need-this-docker-image

I think having a custom --root-path is one of those cases where the combination of Uvicorn plus Gunicorn was problematic.

Now building an image from scratch with Uvicorn should make it much simpler. 🤓