mirror of
https://github.com/jupyterhub/jupyterhub.git
synced 2025-10-11 03:52:59 +00:00
114 lines
5.2 KiB
Markdown
114 lines
5.2 KiB
Markdown
# Fastapi
|
|
|
|
[FastAPI](https://fastapi.tiangolo.com/) is a popular new web framework attractive for its type hinting, async support, automatic doc generation (Swagger), and more. Their [Feature highlights](https://fastapi.tiangolo.com/features/) sum it up nicely.
|
|
|
|
# Swagger UI with OAuth demo
|
|
|
|
|
|
|
|
# Try it out locally
|
|
|
|
1. Install `fastapi` and other dependencies, then launch Jupyterhub
|
|
|
|
```
|
|
pip install -r requirements.txt
|
|
jupyterhub --ip=127.0.0.1
|
|
```
|
|
|
|
2. Visit http://127.0.0.1:8000/services/fastapi or http://127.0.0.1:8000/services/fastapi/docs
|
|
Login with username 'test-user' and any password.
|
|
|
|
3. Try interacting programmatically. If you create a new token in your control panel or pull out the `JUPYTERHUB_API_TOKEN` in the single user environment, you can skip the third step here.
|
|
|
|
```
|
|
$ curl -X GET http://127.0.0.1:8000/services/fastapi/
|
|
{"Hello":"World"}
|
|
|
|
$ curl -X GET http://127.0.0.1:8000/services/fastapi/me
|
|
{"detail":"Must login with token parameter, or Authorization bearer header"}
|
|
|
|
$ curl -X POST http://127.0.0.1:8000/hub/api/users/test-user/tokens \
|
|
-d '{"auth": {"username": "test-user", "password": "mypasswd!"}}' \
|
|
| jq '.token'
|
|
"3fee13ce6d2845da9bd5f2c2170d3428"
|
|
|
|
$ curl -X GET http://127.0.0.1:8000/services/fastapi/me \
|
|
-H "Authorization: Bearer 3fee13ce6d2845da9bd5f2c2170d3428" \
|
|
| jq .
|
|
{
|
|
"name": "test-user",
|
|
"admin": false,
|
|
"groups": [],
|
|
"server": null,
|
|
"pending": null,
|
|
"last_activity": "2021-05-21T09:13:00.514309+00:00",
|
|
"servers": null,
|
|
"scopes": [
|
|
"access:services",
|
|
"access:servers!user=test-user",
|
|
"...",
|
|
]
|
|
}
|
|
```
|
|
|
|
# Try it out in Docker
|
|
|
|
1. Build and run the Docker image locally
|
|
|
|
```bash
|
|
sudo docker build . -t service-fastapi
|
|
sudo docker run -it -p 8000:8000 service-fastapi
|
|
```
|
|
|
|
2. Visit http://127.0.0.1:8000/services/fastapi/docs. When going through the OAuth flow or getting a token from the control panel, you can log in with `testuser` / `passwd`.
|
|
|
|
# PUBLIC_HOST
|
|
|
|
If you are running your service behind a proxy, or on a Docker / Kubernetes infrastructure, you might run into an error during OAuth that says `Mismatching redirect URI`. In the Jupterhub logs, there will be a warning along the lines of: `[W 2021-04-06 23:40:06.707 JupyterHub provider:498] Redirect uri https://jupyterhub.my.cloud/services/fastapi/oauth_callback != /services/fastapi/oauth_callback`. This happens because Swagger UI adds the request host, as seen in the browser, to the Authorization URL.
|
|
|
|
To solve that problem, the `oauth_redirect_uri` value in the service initialization needs to match what Swagger will auto-generate and what the service will use when POST'ing to `/oauth2/token`. In this example, setting the `PUBLIC_HOST` environment variable to your public-facing Hub domain (e.g. `https://jupyterhub.my.cloud`) should make it work.
|
|
|
|
# Notes on security.py
|
|
|
|
FastAPI has a concept of a [dependency injection](https://fastapi.tiangolo.com/tutorial/dependencies) using a `Depends` object (and a subclass `Security`) that is automatically instantiated/executed when it is a parameter for your endpoint routes. You can utilize a `Depends` object for re-useable common parameters or authentication mechanisms like the [`get_user`](https://fastapi.tiangolo.com/tutorial/security/get-current-user) pattern.
|
|
|
|
JupyterHub OAuth uses a token, which can be passed in two places: a `token` url parameter, or an `Authorization: Bearer <token>` header. FastAPI has helper functions that let us create `Security` (dependency injection) objects for each of those. When you need to allow multiple / optional authentication dependencies (`Security` objects), then you can use the argument `auto_error=False` and it will return `None` instead of raising an `HTTPException`.
|
|
|
|
Endpoints that need authentication (`/me` and `/debug` in this example) can leverage the `get_user` pattern and effectively pull the user model from the Hub API when a request has authenticated with cookie / token / header all using the simple syntax,
|
|
|
|
```python
|
|
from .security import get_current_user
|
|
from .models import User
|
|
|
|
@router.get("/new_endpoint")
|
|
async def new_endpoint(user: User = Depends(get_current_user)):
|
|
"Function that needs to work with an authenticated user"
|
|
return {"Hello": user.name}
|
|
```
|
|
|
|
# Notes on client.py
|
|
|
|
FastAPI is designed to be an asynchronous web server, so the interactions with the Hub API should be made asynchronously as well. Instead of using `requests` to get user information from a token/cookie, this example uses [`httpx`](https://www.python-httpx.org/). `client.py` defines a small function that creates a `Client` (equivalent of `requests.Session`) with the Hub API url as it's `base_url` and adding the `JUPYTERHUB_API_TOKEN` to every header.
|
|
|
|
Consider this a very minimal alternative to using `jupyterhub.services.auth.HubOAuth`
|
|
|
|
```python
|
|
# client.py
|
|
import os
|
|
|
|
def get_client():
|
|
base_url = os.environ["JUPYTERHUB_API_URL"]
|
|
token = os.environ["JUPYTERHUB_API_TOKEN"]
|
|
headers = {"Authorization": "Bearer %s" % token}
|
|
return httpx.AsyncClient(base_url=base_url, headers=headers)
|
|
```
|
|
|
|
```python
|
|
# other modules
|
|
from .client import get_client
|
|
|
|
async with get_client() as client:
|
|
resp = await client.get('/endpoint')
|
|
...
|
|
```
|