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

Question

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

Keerthivasan Chinnathambi 0

I created a simple function app by the following the below documentation :https://learn.microsoft.com/en-us/azure/azure-functions/functions-deploy-container?tabs=acr%2Cbash%2Cazure-cli&pivots=programming-language-python

before building a docker image , I have obfuscate using pyarmor tool

and then build the docker image using the docker file and deployed to Azure function using github action,

I have created Azure Function as Container based in Azure Portal

The middleware successfully stated at 8181 port , but

the container app is not started

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

Note :

I have tested the same container in local before deploying to Azure

by running

docker run -p 8080:80

1 answer

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Answer 1

Khadeer Ali 4,615 Microsoft External Staff

@Keerthivasan Chinnathambi ,

Thanks for reaching out. It seems that your Azure Function container is not responding to HTTP pings on port 80, which is causing the site to fail to start. By default, Azure App Service assumes that your custom container listens on port 80. If your application is configured to listen on a different port, such as 8181, you need to set the WEBSITES_PORT app setting in your Azure App Service to match the port your application is using.

You can set this using the Azure CLI with the following command:

az webapp config appsettings set --resource-group <group-name> --name <app-name> --settings WEBSITES_PORT=8181

Make sure to replace <group-name> and <app-name> with your actual resource group and app name.

Additionally, ensure that your Dockerfile has the correct EXPOSE directive for the port your application is listening on. Since you mentioned that the middleware is running on port 8181, it should be reflected in your Dockerfile as follows:

EXPOSE 8181

After making these changes, try redeploying your container to Azure and let us know if you are still facing the issue.

References:

If this answers your query, do click Accept Answer and Yes for "Was this answer helpful." And if you have any further questions, let us know.

Keerthivasan Chinnathambi 0 Reputation points

2025-03-18T16:32:46.1166667+00:00

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
Khadeer Ali 4,615 Reputation points Microsoft External Staff

2025-03-18T16:51:01.9133333+00:00

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
Keerthivasan Chinnathambi 0 Reputation points

2025-03-19T11:44:10.72+00:00

Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
Arko 1,570 Reputation points Microsoft External Staff

2025-03-31T07:44:39.9133333+00:00
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.
Arko 1,570 Reputation points Microsoft External Staff

2025-04-01T13:48:28.5+00:00

Following up on this. Hope your issue is resolved.
Arko 1,570 Reputation points Microsoft External Staff

2025-04-14T04:51:36.64+00:00

Hello Keerthivasan, following up on this. Hope your issue is resolved now.

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

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