This is one of those posts that helps me remember how to do something I knew how to do once but would inevitably forget how to do again one millisecond later. In this case it is how to configure a directory that is shared on the network but only to registered users.
First off, create a new group for the users (I will use the group name sharegroup as an example):
sudo addgroup sharegroup
Then add yourself to the group:
sudo usermod -aG sharegroup $USER
Add any other users to the group in the same way.
Now it is time to prepare the directory to be shared. Create (or choose) the directory and share it using the local network share option from the GUI. Alternatively, edit /etc/samba/smb.conf directly by adding something like this at the bottom:
path = <full path to shared directory>
writeable = yes
guest ok = no
read only = no
browsable = yes
create mask = 0770
directory mask = 0770
valid users = @sharegroup
and then restart samba:
sudo systemctl restart smbd
Then the directory group ownership must be set to the new group. Set the directory as current and enter:
sudo chgrp -R sharegroup *
sudo chgrp sharegroup .
Be very careful any time using the -R option with sudo as it is easy to completely mess up the OS! Generally it is best to start in the directory that’s being modified. That way, there’s less chance of making unintentional modifications.
Now change the permissions to allow group members to operate on files properly:
sudo chmod -R g+rw *
sudo chmod g+rw .
Then the users must be added to samba – for example:
sudo smbpasswd -a $USER
This will ask for a password to be used to access the share. That’s it!