An easy (read: automated) way to set up FTP jails for each user in their respective folder so they can access, upload, and edit site files – with multiple instances on the same server.

A tutorial about FTP configuration with multiple users and directory restriction.

PROFTPD INSTALLATION

Update your packages repository list and install proftpd server

apt-get update && apt-get install proftpd

Then edit proftpd configuration file :

nano /etc/proftpd/proftpd.conf

And just remove the # at the beginning of the line

DefaultRoot                     ~

Restart proftpd server to apply the configuration

service proftpd restart

ADD A NEW FTP USER

To add a user, it requires to define his home folder, which is the website folder you want to use, and to include our ftp user in group www-data.
Just replace the folder and user in the following command :

adduser --home /var/www/yourdomain.ltd/ --ingroup www-data your-ftp-user

The last step is to edit permissions on your website folder

chmod -R g+rw /var/www/domainname

You can now login with your favorite ftp client, and your new user will only be able to access to his home folder.