Resolving the Failed to establish a new connection: [WinError 10060] Error in Python Requests

Learn how to troubleshoot and fix the connection error in Python when using the Requests library to call your Flask web app. This guide covers common issues and solutions.
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Resolving the Failed to establish a new connection: [WinError 10060] Error in Python Requests

If you've ever faced the frustrating error messages like Failed to establish a new connection: [WinError 10060], while working with Flask and the Python Requests library, you're not alone. This problem typically arises when your application, which should connect to an API, fails to establish that connection due to various reasons. In this guide, we will discuss the underlying causes of this error and how to effectively resolve it.

Understanding the Problem

In a simple application setup where you have a client utilizing the Requests library to fetch data from a Flask-based API, you might notice it works flawlessly in a local development environment. However, when deploying the API, a common error is the inability to establish a connection. Here is an example of the error you might encounter:

[[See Video to Reveal this Text or Code Snippet]]

This error indicates that your Python code is attempting to connect to a Flask application running on a specific host and port, but it is unable to do so.

Solutions to the Connection Error

1. Start the Flask Application Correctly

The first thing to check is how the Flask application is initiated. Depending on your deployment, you may need to use the gunicorn server for proper execution, particularly in a production environment:

For Flask applications, use the following command to start your app:

[[See Video to Reveal this Text or Code Snippet]]

For FastAPI applications, the command would differ:

[[See Video to Reveal this Text or Code Snippet]]

These commands set up your application to listen for incoming connections correctly and ensure that long requests do not time out prematurely.

2. Configuring Azure Settings

If you are deploying your application on Azure, remember that configuring the port settings correctly is vital. Azure App Service offers automatic port detection, and often, your app needs to expose port 80 or 443 publicly.

You can specify an app setting named WEBSITES_PORT in the Azure configuration, assigning it the port number your app is expected to run on. Keep in mind, however, that opening ports other than 80/443 is not allowed in Azure's PaaS environment.

3. Testing Network Configuration

It is also wise to investigate your current network configuration, especially if you are behind a corporate proxy or firewall that may be blocking your connection attempts. Verify that:

Your application has permissions through the firewall to make outgoing requests.

The URL used is reachable from your application environment.

4. Debugging Tips

Inspect your code for issues with the URL or incorrect endpoint usage.

Use tools like curl or Postman to verify that the endpoint is accessible from your network.

Conclusion

The Failed to establish a new connection: [WinError 10060] error can be daunting, but with the right startup configurations and checks in place, you can effectively troubleshoot it. By ensuring that your Flask application is running properly and that your Azure settings are correctly configured, you can eliminate many potential sources of this error and foster a smoother development experience.

If you have any further questions or run into additional issues, feel free to leave a comment below!