This is the way how can you connect google colab as well as google drive (mounted) using SSH. This is useful when you want to download data directly to your google drive specially for machine learning purpose. It can be easy to mount google drive and use files into for your code.

Connect Google Colab+Drive with SSH.ipynb

http://localhost:4040/api/tunnels is not available. Hence, giving a

ConnectionError: HTTPConnectionPool(host='localhost', port=4040): Max retries exceeded with url: /api/tunnels (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x7c1f67e215a0>: Failed to establish a new connection: [Errno 111] Connection refused'))

I'd likely at least amend this to include a direct reference to NGrok, if that's what you want to use for tunneling. Blindly downloading binaries from other sites generally isn't recommended.

I'd also recommend not completely overwriting the sshd_config file, but using a local config for the user, instead (read: there's likely a better way to do this tunnel).