Example for org.apache.ftpserver on JRuby

ftp-example.rb

require "java"

jars = File.join(File.dirname(__FILE__), "*.jar")
Dir[jars].each { |jar| require jar }

import org.apache.ftpserver.FtpServer
import org.apache.ftpserver.FtpServerFactory
import org.apache.ftpserver.listener.ListenerFactory

server_factory = FtpServerFactory.new
listener_factory = ListenerFactory.new

listener_factory.port = 2221

server_factory.add_listener "default", listener_factory.create_listener

server = server_factory.create_server

# start the server
server.start

To try this on your own machine download the 1.0.6 release of Apache's FTP Server: http://mina.apache.org/ftpserver/downloads.html

Extract it, then copy the jar files from ./common/lib. You can copy all of them, but you only need mina_, ftplet_ ftpserver_, log4j_ and slf4j* files.

We're starting the server on port 2221 in this example because 21 is a privileged port. So this way we don't need root access just to try our example.

If you look at line 129 here: http://svn.apache.org/viewvc/mina/ftpserver/trunk/core/src/main/java/org/apache/ftpserver/command/impl/LIST.java?view=markup#L129

And line 196 here:
http://svn.apache.org/viewvc/mina/ftpserver/trunk/core/src/main/java/org/apache/ftpserver/command/CommandFactoryFactory.java?view=markup#L196

You start to get an idea of how you could easily bend the library to your will, allowing you to create a "Rails for FTP".

@fgrehm FYI, thought you might find this interesting. :)

Here's an example of adding/overriding the defaults with your own commands: http://mail-archives.apache.org/mod_mbox/mina-ftpserver-users/201003.mbox/%3Cf63349b31003220848n4ce950a9m1f8856ee508e6585@mail.gmail.com%3E

The list of commands you'd need to appropriately override to create a dynamic FTP server isn't exactly short (start at line 89 here: http://svn.apache.org/viewvc/mina/ftpserver/trunk/core/src/main/java/org/apache/ftpserver/command/CommandFactoryFactory.java?view=markup#L89) , but most of the ones you'd have to touch probably map pretty easily to a REST-alike interface.

Also, unlike with ProFTPd, with this you could BCrypt your user database, and authenticate directly against it in your FTP server.