simple-ftpd v0.0.4
simple-ftpd
simple-ftpd is a event based ftp-server for node.js.
Features
- Supports multiple modern ftp clients such as FileZilla, WinSCP, Transmission.
 - A real File System is not required.
 - For now it only supports basic authentication.
 - It supports passive mode only.
 - It only supports streams for writing and reading files.
 - It currently only supports a subset of FTP commands, but it should be enough for any modern FTP client.
 - It is intended to be used mainly to create local network ftp servers.
 
Used pyftpdlib extensively as a reference for the FTP protocol specification, as reading RFC documents is super boring :=)
Install
yarn add simple-ftpd
# or
npm install simple-ftpd --saveconst ftpd = require('ftpd')API
Syntax: ftpd(opts, sessionCallback) or ftpd(host:port, sessionCallback)
Should you need more control, the ftpd function will return a net.Server instance.
Example
Simple, fs-based ftp server implementation example:
'use strict'
const ftpd = require('ftpd')
ftpd({ host: '127.0.0.1', port: 1337, root: '/public/files' }, (session) => {
  session.on('pass', (username, password, cb) => {
    if (username === 'superadmin' && password === '53cr3t') {
      session.readOnly = false
      session.root = '/private/secret/files'
      cb(null, 'Welcome admin')
    } else {
      cb(null, 'Welcome guest')
    }
  })
  session.on('stat', fs.stat)
  // AKA
  // session.on('stat', (pathName, cb) => {
  //  fs.stat(pathName, cb)
  // })
  session.on('readdir', fs.readdir)
  // AKA
  // session.on('readdir', (pathName, cb) => {
  //   fs.readdir(pathName, cb)
  // })
  session.on('read', (pathName, offset, cb) => {
    cb(null, fs.createReadStream(pathName, { start: offset }))
  })
  session.on('write', (pathName, offset, cb) => {
    cb(null, fs.createWriteStream(pathName, { start: offset }))
  })
  // I'd do some checking if I were you, but hey.
  session.on('mkdir', fs.mkdir)
  session.on('unlink', fs.unlink)
  session.on('rename', fs.rename)
  session.on('remove', require('rimraf'))
})Options
| option | description | |
|---|---|---|
host | required | Must be a valid ipv4 address (for now). Defaults to 127.0.0.1 | 
port | required | Server port. Defaults to 1337. | 
readOnly | optional | Disables client write requests. Defaults to true. Can be overridden on a connection-basis by setting the readOnly property on the session object before logging in. | 
root | optional | The path passed to events will always be joined to root. Can be overridden on a connection-basis by setting the root property on the session object before logging in. The ftp client will not see root, and will think he's at /. This is simply a convenience to avoid manually joining the path you get in every event. | 
maxConnections | optional | Maximum number of server connections. Defaults to 10. | 
Passive connections will be initialized on an unused port assigned by the os.
Instead of options, you can pass ${host}:${port} ("192.168.1.10:1337").
Events
Every event gets some arguments and a node-style callback you must call with an Error object (if any) and results.
If you do not listen to a specific event, then that feature will become unavailable to the client.
For example, if you do not listen to write events, the client will get a 502 error when trying to write files.
pass [username, password, cb]
The client wants to login with username and password.
Will consider the user logged in if no error is passed to cb()
User names are always accepted, because (from pyftpdlib):
In order to prevent a malicious client from determining valid usernames on a server, it is suggested by RFC-2577 that a server always return 331 to the USER command and then reject the combination of username and password for an invalid username when PASS is provided later.
read [pathName, offset, cb]:
The client wants to read the file at pathName, starting at offset.
Requires a readable stream to be passed as cb(null, readStream).
write [pathName, offset, cb]:
The client wants to write a file at pathName, starting at offset.
Requires a writable stream to be passed as cb(null, writeStream).
stat [pathName, cb]:
the client wants the stats to a file or directory at pathName.
Requires a fs.stat-like object to be passed as cb(null, stat).
Properties are:
{
  // fs.stat mode
  mode: 16822,
  //  size in bytes
  size: 12345,
  // lastModifiedTime as Date or number (or whatever gets parsed by moment)
  mtime: Date.now(),
  // optional, will use it for display if available, otherwise "owner"
  uname: 'kamicane',
  // optional, will use it for display if available, otherwise "group"
  gname: 'admins',
}readdir [pathName, cb]:
The client wants a list of files in the directory pathName. requires an array of file names, relative to pathName, to be passed as cb(null, list).
mkdir [pathName, cb]:
The client wants to create a directory at pathName.
Will consider the directory written if no error is passed to cb()
unlink [pathName, cb]:
The client wants to delete the file at pathName.
Will consider the file deleted if no error is passed to cb()
remove [pathName, cb]:
The client wants to remove a directory, and all of its contents, at pathName.
Will consider the directory and its contents removed if no error is passed to cb()
rename [fromName, toName, cb]:
The client wants to rename a file or directory, from fromName to toName.
Will consider the file renamed if no error is passed to cb()
CLI
When installed globally, ftpd will provide a small cli, which will quickly create a fs-based ftp server.
You can use it like this:
ftp-server /public/files --host 192.168.0.1 --port 1234 --max-connections 10--hostwill default to127.0.0.1--portwill default to1337--max-connectionswill default to10--read-onlywill default totrue- Unless specified, the ftp root will default to 
process.cwd() 
The cli will accept any login, so be careful when setting --read-only to false.
License
MIT