[dsissitka]

If you're a Linux user you might like Firejail for this.

  firejail --appimage --net=none --private=~/path/to/jail ~/path/to/Obsidian.AppImage

--private=~/path/to/jail limits access to your home directory to ~/path/to/jail and when you don't want Obsidian to have internet access you can take it away with --net=none.

[elric]

Note that if you already have an Obsidian vault, suddenly jailing it might break things. Obsidian stores a bunch of state in ~/.config/obsidian which will no longer be valid. And amusingly/frustratingly, the GTK file picker doesn't take the jail into account and seems to produce invalid paths.

And because --private mounts some bits as temporary filesystems, you might end up losing state. Try before you buy.

[sph]

And all of these issues such as sandboxing and portals are solved by using the Flatpak version instead.