errorMessage: Unable to determine handler from trigger event

[VictorBac]

Hey guys,

I am trying to build d coker iamge to deploy on aws lambda following the doc and:
https://docs.aws.amazon.com/lambda/latest/dg/images-create.html#images-create-from-base
https://docs.aws.amazon.com/lambda/latest/dg/python-image.html#python-image-base

My Dockerfile:

FROM public.ecr.aws/lambda/python:3.8

# Copy function code
COPY app.py ${LAMBDA_TASK_ROOT}

# Install the function's dependencies using file requirements.txt
# from your project folder.

COPY requirements.txt  .
RUN  pip3 install -r requirements.txt --target "${LAMBDA_TASK_ROOT}"

# Set the CMD to your handler (could also be done as a parameter override outside of the Dockerfile)
CMD [ "app.handler" ]

requirement.txt:

fastapi == 0.71.*
uvicorn[standard]
mangum == 0.12

app.py:

from fastapi import FastAPI
from mangum import Mangum

app = FastAPI()


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: str = None):
    return {"item_id": item_id, "q": q}

handler = Mangum(app, spec_version=2)

then:

docker build -t hello-world .
docker run -p 9000:8080 hello-world

But when I try to query locally (following the doc):

$ curl -XPOST "http://localhost:9000/2015-03-31/functions/function/invocations" -d '{}'
{
  "errorMessage": "Unable to determine handler from trigger event",
  "errorType": "TypeError",
  "stackTrace": [
    "  File \"/var/task/mangum/adapter.py\", line 86, in __call__\n    handler = AbstractHandler.from_trigger(\n",
    "  File \"/var/task/mangum/handlers/abstract_handler.py\", line 113, in from_trigger\n    raise TypeError(\"Unable to determine handler from trigger event\")\n"
  ]
}

I tried using (found in some discussions)

handler = Mangum(app, spec_version=2)

and even from another discussion:

import uvicorn
from fastapi import FastAPI
from mangum import Mangum
# TODO: Add this line
from starlette.middleware.cors import CORSMiddleware

app = FastAPI(title="FastAPI Mangum Example", version='1.0.0')

# TODO: Add these lines
app.add_middleware(
    CORSMiddleware,
    allow_origins='*',
    allow_credentials=False,
    allow_methods=["GET", "POST", "OPTIONS"],
    allow_headers=["x-apigateway-header", "Content-Type", "X-Amz-Date"],
)

handler = Mangum(app)


@app.get('/', name='Hello World', tags=['Hello'])
def hello_world():
    return {"Hello": "Python"}


if __name__ == '__main__':
    uvicorn.run(app)

it never works. (same error when deployed to aws lamda and not run locally)

I tried to use previous version but also had issue...
does anyone has a working example for this ?