Handling Keycloak and Fastapi error messages

[jonra1993]

I really appreciate that you created this package. it is something I was looking for too much time ago. I have been using it and I face the following problem I see that the Keycloak exception is fired but it is not passed to fast API which shows 500 error. Do you know how can I pass the error message to Swagger?

This is the API I am trying to use:

@app.post("/users2")
def create_user(first_name: str, last_name: str, email: str, password: SecretStr):
    return idp.create_user(first_name=first_name, last_name=last_name, username=email, email=email, password=password.get_secret_value(), send_email_verification=False)

[twistfire92]

you can try to override exception handlers

[yannicschroeer]

You should define a custom error handler in your FastAPI app for the KeycloakError that catches the error and returns the error message:

@app.exception_handler(KeycloakError)
async def keycloak_exception_handler(request: Request, exc: KeycloakError):
    return JSONResponse(
        status_code=exc.status_code,
        content={"message": exc.reason},
    )

Instead of throwing the error and raising a 500, the app should now proxy the errors as expected.

@jonra1993 Thank you for your question, we're going to add this to the documentation

[jonra1993]

Thanks, @yannicschroeer your solution worked as expected

[jonra1993]

Hello, @yannicschroeer I have created a PR to add this into documentation please check it #54

[yharby]

Hello, Not working for me (create user endpoint as well as keycloak_exception_handler) as I am using router instead of app also tried

from backend.core.config import settings
from backend.secret import router
from fastapi import FastAPI, Request
from fastapi.responses import JSONResponse
from fastapi_keycloak import KeycloakError


def keycloak_exception_handler(request: Request, exc: KeycloakError):
    return JSONResponse(
        status_code=exc.status_code,
        content={"message": exc.reason},
    )

def create_application() -> FastAPI:
    application = FastAPI(title=settings.PROJECT_NAME)
    application.include_router(router)
    return application


app = create_application()
app.add_exception_handler(KeycloakError, keycloak_exception_handler)

You should define a custom error handler in your FastAPI app for the KeycloakError that catches the error and returns the error message:

@app.exception_handler(KeycloakError)
async def keycloak_exception_handler(request: Request, exc: KeycloakError):
    return JSONResponse(
        status_code=exc.status_code,
        content={"message": exc.reason},
    )

Instead of throwing the error and raising a 500, the app should now proxy the errors as expected.

@jonra1993 Thank you for your question, we're going to add this to the documentation

[jonra1993]

Hello, @Youssef-Harby can you try this setup using containers it worked in my case I plan in the future migrate this project to AuthN and AuthZ using keycloak it is still a work in progress, but you can check the setup and package versions.

https://github.com/jonra1993/fastapi-alembic-sqlmodel-async/blob/development/fastapi-alembic-sqlmodel-async/app/main.py