Deploying Flask

How do I deploy my Copilot Extension Flask app to my newly created EC2 instance?

In the first GitHub Copilot Extension Learning Path, you created a Flask app in the section titled “ How can I create my own private GitHub Copilot Extension? ”.

You will now deploy this Flask app on your newly created EC2 instance. First, retrieve your EC2 instance ID:

    

        
        
aws ec2 describe-instances --filters "Name=tag:Name,Values=CopilotExtensionDeploymentStack/LaunchTemplate" --query "Reservations[*].Instances[*].InstanceId" --output text

    

Next, use this ID to log in with AWS SSM. Because your instance is in a private subnet for security purposes, you must use SSM.

The SSM agent running on the instance creates a secure tunnel that lets you SSH in with the following command:

    

        
        
aws ssm start-session --target [your instance ID]

    

You can now follow the steps in “ How can I create my own private GitHub Copilot Extension? ” to create your Flask app, set up a Python virtual environment, and install the necessary packages.

The only two changes that you need to make are:

• Add a health check endpoint for the Application Load Balancer (ALB).
• Run your app on 0.0.0.0 port 8080, which the ALB is configured to listen on.

First, add the following endpoint to your main Flask file:

    

        
        
@app.route('/health')
def health():
    return Response(status=200)

    

Next, add the host argument to the app.run call at the end of the file and update the port number.

The final result should look like this:

    

        
        
if __name__ == '__main__':
    app.run(host='0.0.0.0', port=8080)

    

This exposes your app to the port that the ALB listener is monitoring.

Run the simple extension:

    

        
        
python ./simple-extension.py

    

Now, if you navigate to your API subdomain in a browser, you should see:

    

        
        
"Hello! Welcome to the example GitHub Copilot Extension in Python!"

    

Your API is now complete and ready to be configured in your GitHub Application.