End Point   Welcome to End Point's blog  Ongoing observations by
End Point people.  SFTP virtual users with ProFTPD and Rails:
Part 1   ProFTPD's virtual users concept allows you to point
ProFTPD at a SQL database for your user and group
authentication. This means SFTP logins don't need actual system
logins (although you can mix and match if you want). Naturally,
this is perfect for dynamically creating and destroying SFTP
accounts. Give your web app the ability to create disposable
SFTP credentials and automatically clean up after the user is
done with them, and you have a self-maintaining system.
Starting from the inside-out, you need to configure ProFTPD to
enable virtual users. Here are the relevant parts from our
proftpd.conf:  # Begin proftpd.conf excerpt. For explanation of
individual config directives, see the  # great ProFTPD docs at
http://www.proftpd.org/docs/directives/configuration_full.html
DefaultServer off Umask 002 AllowOverwrite on  # Don't reference
/etc/ftpusers UseFtpUsers off  # Enable