Timeout Issue in requesting VM

Question

I created a virtual machine on Azure portal with default configuration and I started a flask web server within just to test an application that I'm developing<br>

The case is that if I send any request to the machine it will be "time outed" and not any request is present in the Flask debugger.

I tried in another approach to ping the machine using it public IP address but it also results in a timeout.

PS: My machine is Ubuntu.

Answer 1

@Adel Hamdi

Thank you for reaching out to the Microsoft Q&A platform.

If you've created a virtual machine on Azure and started a Flask web server on it, but you're experiencing timeouts when trying to access it, there could be several reasons for this issue. Let's go through some troubleshooting steps to identify and resolve the problem:

1. Check Network Security Group (NSG) rules: Azure VMs are usually associated with Network Security Groups that control inbound and outbound traffic. By default, Azure blocks all incoming traffic except for a few specific ports like SSH (port 22) for Linux VMs and RDP (port 3389) for Windows VMs. Ensure that you have allowed incoming traffic on the port your Flask application is running (typically port 80 for HTTP or port 443 for HTTPS).
2. Check Firewall settings within the VM: Even if the NSG allows incoming traffic on the appropriate port, the VM's firewall may still be blocking the requests. Make sure that the firewall within the VM is configured to allow incoming requests on the necessary port. Ubuntu comes with a firewall called ufw that may be blocking incoming traffic. You can check the status of the firewall by running the command sudo ufw status. If the firewall is enabled, you will need to add a rule to allow traffic to the port that your Flask web server is listening on. You can do this by running the command sudo ufw allow <port>.
3. Check Flask app's host and port settings: Ensure that your Flask application is listening on the correct host and port. When running locally, Flask's development server typically listens on localhost by default. However, in a production environment like Azure VM, you need to make sure the app listens on all available interfaces (0.0.0.0) so that external requests can reach it.
4. Check the application logs: Check the logs of your Flask application to see if there are any errors or issues that could be causing the timeouts. You can also check the system logs on the VM to see if there are any relevant messages.

Check if another process is using the port: Ensure that there is no other process running on the same port on the VM. If another process is using the port, you might need to either stop that process or change the port for your Flask application.

Restart the Flask application: After making any necessary configuration changes, restart your Flask application to apply the changes.

By going through these steps, you should be able to identify the issue and get your Flask application running and accessible on your Azure VM. If you're still facing problems, double-check the configurations and settings to ensure they are correct and that the VM is reachable from the internet.

If this does answer your question, please accept it as the answer as a token of appreciation.

Answer 2

The issue you are having can be due to the necessary ports are being blocked to accept the traffic you are looking for. Two ways you can check it

1. Check the necessary outbound ports are opened as below

1. Check the firewall status in the machine and see the firewall is blocking the required packets.

sudo ufw status
Status: active

Above status shows that firewall is active in your virtual machine

1. Disable the firewall and see if it allows the packets you are expected to see

sudo ufw disable

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