Container didn't respond to HTTP pings on port 80, failing site start while container to azure apps

I have added EXPOSE 8181 in Dockerfile and WEBSITES_PORT 8181 in Environmental variable of Azure Function and it is not working,

Please note before making the container image am making the code obfuscation using pyarmor,

Thanks

Keerthi

Keerthivasan Chinnathambi,

Have you tried executing the following command inside your container to see which ports are open:

docker run -it <image-name> /bin/sh

netstat -tulnp

Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name

Hi Keerthivasan, the core problem seems to be that your Azure Function container is starting a server on port 8181, while Azure expects the container to respond to HTTP traffic on port 80 by default. Although setting WEBSITES_PORT=8181 works for some services like Azure Web Apps, it typically doesn't work for Azure Functions hosted in Linux containers — Azure still expects an HTTP response on port 80 for health checks.

If you're using a custom handler (e.g., a FastAPI app running via Uvicorn), you'll need to explicitly make it listen on port 80. For example:

uvicorn.run(app, host="0.0.0.0", port=80)

Make sure your Dockerfile also reflects this by exposing port 80: EXPOSE 80 and your container’s CMD should launch your server correctly: CMD ["python", "main.py"]. This should ensure Azure can reach your app via the expected port.

If you’re not using a custom handler and are relying on the default Azure Functions runtime, you don’t need to start your own HTTP server. Instead, you should base your Docker image on Microsoft’s official Azure Functions Python image:

FROM mcr.microsoft.com/azure-functions/python:4-python6

COPY . /home/site/wwwroot

WORKDIR /home/site/wwwroot

ENV AzureWebJobsScriptRoot=/home/site/wwwroot \

    AzureFunctionsJobHost__Logging__Console__IsEnabled=true

No need to expose ports or start a server manually in this case — the Functions runtime handles that.

Since you're using PyArmor to obfuscate your code, make sure it doesn’t interfere with how Azure loads your function app. Avoid obfuscating host.json, function.json, or any startup logic used by the Functions runtime. It's best to limit obfuscation to the actual function logic, and not the structural files Azure needs to wire everything together.

As suggested earlier, you can run this to double-check which ports your container is actually listening on:

docker run -it <your-image-name> /bin/sh

netstat -tulnp

This can help confirm whether your app is correctly binding to port 80. Let me know if you're using a custom handler or the default runtime. The right solution depends on that.

Following up on this. Hope your issue is resolved.