Facing issue in deploying a Quart application in Azure Durable Funtions with Docker

Question

I am trying to deploy a python Quart application to Azure function with Docker. Below is my Docker file. My Azure function is failing to start. I get "Application error" when accessing the function URL. I would appreciate any help here in verifying if my dockerfile and main function is correct

Dockerfile:

FROM mcr.microsoft.com/azure-functions/python:4-python3.11
ENV AzureWebJobsScriptRoot=/home/site/wwwroot \    AzureFunctionsJobHost__Logging__Console__IsEnabled=true# Copy the function app files to the appropriate location in the container
COPY . /home/site/wwwroot# Install dependencies
RUN pip install --upgrade pip
RUN pip install -r /home/site/wwwroot/requirements.txt
EXPOSE 8080

WrapperFuntion--> init.py:

import azure.functions as func
import azure.durable_functions as duf

from common_util.utilities import logger
from FlaskApp import flask-app
from quart import g


async def main(req: func.HttpRequest, mappingColumnsConfig: func.InputStream, starter: str, context: func.Context) -> func.HttpResponse:
    async with flask_app.app_context():
        
        g.client = duf.DurableOrchestrationClient(starter)
        g.mapping_columns_config = mappingColumnsConfig
        g.function_name = req.route_params["functionName"]
        
        
        response = await func.AsgiMiddleware(app=flask-app.asgi_app).handle_async(req, context)
        
        status_code = response.status_code
        headers = dict(response.headers)
        body = response.get_body()
        
        
        return func.HttpResponse(body, status_code=status_code, headers=headers)

FlaskApp--> init.py:

from quart import Quart
from quart_cors import cors


flask-app = Quart(__name__)
flask-app = cors(flask-app)


@app.post("/api/pets/upload-petdata")
async def upload_petdata_route():
    try:
        ----DB insert----

    except Exception as e:
    logger.error(f"Pets data inert operation failed")

I tried running the function with func start and its running. But if I try to run the function with docker in local I am getting "Function host not running" . If I deploy the container directly to Azure function , the function is failing to start

Answer 1

I get "Application error" when accessing the function URL.

This error occurs if the function is not deployed properly. Check the kudu site of the function app if you can see all the files of your function.

I have created a sample Python Durable Azure functions with Quart.

Code Snippet:

import azure.durable_functions as duf
import azure.functions as func
from quart import g

from flaskApp import flask_app

async def main(req: func.HttpRequest,  context: func.Context) -> func.HttpResponse:

    response = await func.AsgiMiddleware(app=flask_app.asgi_app).handle_async(req, context)
    
    status_code = response.status_code
    headers = dict(response.headers)
    body = response.get_body()

    return func.HttpResponse(body, status_code=status_code, headers=headers)

flaskApp=>init.py:

import azure.functions as func
from quart import Quart
from quart_cors import cors

flask_app = Quart(__name__)
flask_app = cors(flask_app)

@flask_app.post("/api/pets/upload-petdata")
async def upload_petdata_route():
    try:
     return {"message": "Pet data inserted successfully!"}, 200
    except Exception as e:
        return {"error": "Pets data insert operation failed"}, 500

Dockerfile:

FROM mcr.microsoft.com/azure-functions/python:4-python3.11

ENV AzureWebJobsScriptRoot=/home/site/wwwroot \
    AzureFunctionsJobHost__Logging__Console__IsEnabled=true

COPY requirements.txt /
RUN pip install -r /requirements.txt

COPY . /home/site/wwwroot

local Response:

Build the docker image:

Able to run the docker image of the function with the command docker run -p 8080:80 <docker_image>:

Add the required Application settings in the function app.

Deployed to Azure:

Portal: