A Quick Guide to Configuring ProFTPd

Installing ProFTPD (applies to version 1.3.6):

sudo apt update
sudo apt install proftpd

Add the following lines to /etc/proftpd/proftpd.conf:

Port 10109
DefaultRoot ~
RequireValidShell off
AuthUserFile /etc/proftpd/ftpd.passwd
AuthGroupFile /etc/proftpd/ftpd.group
AuthOrder mod_auth_file.c

Create a user:

sudo ftpasswd --passwd --file=/etc/proftpd/ftpd.passwd --name=web --change-password

Create a group:

sudo ftpasswd --group --name=www-data --file=/etc/proftpd/ftpd.group --gid=60 --member web

gid must match the gid in /etc/group

Set file permissions:

chmod 440 /etc/proftpd/ftpd.*

Test the config:

sudo proftpd -t

Start it:

sudo systemctl start proftpd