I followed this x11 Forwarding - Apple Community to configure my macbook pro. So I can use `ssh -Y user@ip` to connect to my macbook from ubuntu 18.04 without warning and error. But the `open -a AppName` comand just open the app on my laptop without forwarding. Is there anything I missed? How can I see the GUI on my ubuntu OS?
MacBook Pro Retina
X11 forwarding requires the two systems to be using X11. macOS does not use X11 so you would need to install this on the Mac if you wanted X11 forwarding. You do not need X11 to access the Mac's GUI from Linux. You just need to go into the "Sharing" preferences or possibly "Remote Management" section and make sure to enable "VNC" as it is not selected by default.
See this article:
https://support.apple.com/guide/mac-help/turn-screen-sharing-on-or-off-mh11848/mac
Using SSH & VNC together:
https://www.techrepublic.com/article/how-to-connect-to-vnc-using-ssh/
The only way the GUI would forward is if it is some form of X-window app that your installation of Ubuntu has a capability to display.
I'am a little confused. What is the meaning of `install X Windows on the Mac`? Does the `VNC mode` refer to the `System Preference` > `Sharing` > `Screen Sharing` service of Mac? It is used to connect the entire GUI of my Mac, right? I just need to see some applications' GUI, not the entire OS GUI.
Thank you for your explanation.
Unless you install X Windows on the Mac you cannot use X11 forwarding. If you want to access the macOS from Ubuntu, you need to enable VNC mode in the Remote Management section on macOS. Then you can use any VNC app on Ubuntu to connect to the Mac. If you want a secure connection, then make sure to first connect to the Mac via ssh. Some VNC apps have an ssh option built-in.
using `ssh -Y user@ip` to connect to my macbook from ubuntu 18.04
