I've spent hours searching for an answer to this problem before deciding to create an account and ask myself:
OS: Ubuntu 18.04
I have a folder named "servers"
Inside this folder, files are generated and edited by a process under the user "pufferd" (game server powered by PufferPanel)
I wish to allow other users to modify, create, and delete files within this folder through FTP (I do not wish to use the SFTP provided by PufferPanel)
However, everything I've found and tried has failed to allow a psuedo "dual ownership" of the folder.
I've tried changing permissions, I've tried setting the owner-group of the folder, it's seemingly impossible to allow both users to create files and be interchangeable without any permission issues whatsoever.
Files uploaded through the FTP user are read-only to "pufferd"
Files created by "pufferd" are read-only to the FTP user.
What is the simplest solution to this? Ideally all files in the folder, regardless of owner or creation origin (server-made, ftp uploaded, or other) are readable, writable, and executable by each user with folder access.