Install proftpd FTP server

wget https://raw.githubusercontent.com/panticz/installit/master/install.proftpd.sh -O - | bash -

#!/bin/bash

debconf-set-selections <<\EOF
proftpd-basic shared/proftpd/inetd_or_standalone select standalone
EOF

# install
apt-get install proftpd
# ServerType: standalone

# configure 
sed -i 's|# RequireValidShell|RequireValidShell|g' /etc/proftpd/proftpd.conf
sed -i 's|# DefaultRoot|DefaultRoot|g' /etc/proftpd/proftpd.conf
cat <<EOF>> /etc/proftpd/proftpd.conf
<Limit LOGIN>
    DenyGroup !ftpuser
</Limit>
EOF

# create ftpuser group
addgroup ftpuser

# restart
/etc/init.d/proftpd restart

Create new ftp user
adduser ftp_user_1 -shell /bin/false -home /var/www/ftp_user_1/

# add ftp user to grup
adduser ftp_user_1 ftpuser

# clear user dir
rm /var/www/ftp_user_1/.*

Links
http://www.thomas-krenn.com/de/wiki/FTP-Server_unter_Debian_einrichten
http://www.debian-administration.org/article/228/Setting_up_an_FTP_server_on_Debian