sftp (restricted) from a pyspark notebook

Question

Hello

I need to access an sftp site from a pyspark notebook, however, this site is restricted and can be only accessed from a previously identifed IP address (whitelist)

Is this posible?

Thanks for your help

Answer 1

Yes, accessing an SFTP site with IP restrictions from a PySpark notebook (like those used in Azure Synapse Analytics) is possible. However, it requires ensuring that the IP address or range of IPs you are working from is whitelisted on the SFTP server.

Steps:

1. Whitelist the IP Addresses: Ensure that the IP addresses used by the Azure Synapse Spark cluster (or the notebook environment) are whitelisted on the SFTP server. This is done on the SFTP server side, and you may need to work with the SFTP administrator to add the IP addresses to the allowed list.
   • You can get the public IP addresses used by your Synapse environment from the Azure portal under the "Networking" section or by checking the IP ranges in the Azure documentation.
2. Use PySpark to Connect to the SFTP Server: Once the IP addresses are whitelisted, you can use a combination of PySpark and the Paramiko library (for SSH and SFTP operations) in your notebook to access the SFTP server. Here’s a sample code snippet using Paramiko in a PySpark notebook:

   
      import paramiko
   
      import io
   
      # Create an SFTP client using Paramiko
   
      ssh = paramiko.SSHClient()
   
      ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
   
      
   
      # Connect to the SFTP server (replace with your credentials and server details)
   
      ssh.connect(hostname='sftp.example.com', username='your_username', password='your_password', port=22)
   
      # Start an SFTP session
   
      sftp = ssh.open_sftp()
   
      # Download a file
   
      with io.BytesIO() as file_obj:
   
          sftp.getfo('/path/to/remote/file', file_obj)
   
          file_obj.seek(0)
   
          # You can now read from `file_obj` or process the file as needed in PySpark
   
      # Close the SFTP connection
   
      sftp.close()
   
      ssh.close()
   
   

3. Network Security Configurations in Azure Synapse: If your Synapse workspace has additional network restrictions (like firewall or private link settings), ensure that:
   • The Spark cluster has outbound internet access to reach the SFTP server.
   • You may also need to configure network security groups (NSGs) or service endpoints in Azure.
4. Handling Keys Instead of Passwords: If the SFTP server requires SSH key-based authentication, you can modify the Paramiko connection to use a private key file:

   
      ssh.connect(hostname='sftp.example.com', username='your_username', key_filename='/path/to/private/key')
   
   

Let me know if you need more help with this setup!