FTPConnectionClosedException: Connection closed without indication

I'm trying to connect with FTP server, deployed from docker image, using Apache client:

import org.apache.commons.net.ftp.FTPClient

import java.io.IOException

object FtpClient {

  def main(args: Array[String]): Unit = {

    val ftpClient = new FTPClient()

    try {
      ftpClient.connect("localhost", 21)
      val success = ftpClient.login("one", "1234")

      if (success) {
        println("Success connect")
      }

    } catch {
      case e: IOException => throw new RuntimeException(e)
    } finally {
      // 
    }

  }
}

FTP server run by:

docker run -d     -p 21:21     -p 21000-21010:21000-21010     -e USERS="one|1234"     -e ADDRESS=ftp.site.domain     delfer/alpine-ftp-server

And I receive the following error:

      Exception in thread "main" java.lang.RuntimeException: org.apache.commons.net.ftp.FTPConnectionClosedException: Connection closed without indication.
at ru.spb.client.FtpClient$.main(FtpClient.scala:23)
at ru.spb.client.FtpClient.main(FtpClient.scala)
     Caused by: org.apache.commons.net.ftp.FTPConnectionClosedException: Connection closed without indication.
at org.apache.commons.net.ftp.FTP.getReply(FTP.java:568)
at org.apache.commons.net.ftp.FTP.getReply(FTP.java:556)

EDIT:

Docker logs returns:

Changing password for one
New password: 
Bad password: too short
Retype password: 
adduser: /ftp/one: No such file or directory
passwd: password for one changed by root
seems like pidfd_open syscall does not work, falling back to 
polling
failed to watch for direct child exit (pidfd_open error): Operation not permitted

Maybe I miss some significant connection settings?

Solution

FTP Container - Docker run command:

docker run -d \
  -p 21:21 \
  -p 21000-21010:21000-21010 \
  -e USERS="one|Passw0rd!" \
  -e ADDRESS=ftp.site.domain \
  delfer/alpine-ftp-server

-e USERS="one|Passw0rd!" , Password 1234 is too short, so change password to Passw0rd! or others
-e ADDRESS=ftp.site.domain, ftp.site.domain is your ftp server name.

edit your /etc/hosts

add ftp.site.domain to 127.0.0.1

127.0.0.1   localhost ftp.site.domain

A quick alternative

find ftp container id

docker ps

if container id is 05da9c08858f

open into ftp container

docker exec -it 05da9c08858f sh

Check if the ftp service is running?

in container , run command:

netstat -tulnp | grep :21

if return nothing, ftp service is not running.

start ftp service

vsftpd /etc/vsftpd/vsftpd.conf

run command again:

netstat -tulnp | grep :21

return: ( ftp service is running. )

netstat -tulnp | grep :21
tcp        0      0 0.0.0.0:21              0.0.0.0:*               LISTEN      45/vsftpd

exit container:

exit

Note:

I didn’t spend more time to check why the ftp service was not started by default in the docker run command, so I just provide a quick solution: enter the Container and start the ftp service manually.

Your Test App

FtpClient.scala

Change FTP Server to ftp.site.domain
Change Password to Passw0rd!

import org.apache.commons.net.ftp.FTPClient
import java.io.IOException

object FtpClient {

def main(args: Array[String]): Unit = {

val ftpClient = new FTPClient()

  try {
    ftpClient.connect("ftp.site.domain", 21)
    val success = ftpClient.login("one", "Passw0rd!")
    if (success) {
      println("Success connect")
    }
  } catch {
    case e: IOException => throw new RuntimeException(e)
  } finally {
// 
}

}
}

Download jar file:

Download commons-net-3.9.0.jar(https://repo1.maven.org/maven2/commons-net/commons-net/3.9.0/commons-net-3.9.0.jar)

Check version

$ scala -version
Scala code runner version: 1.5.4
Scala version (default): 3.6.4

Run App

$ scala -classpath "commons-net-3.9.0.jar" FtpClient.scala
Compiling project (Scala 3.6.4, JVM (21))
Compiled project (Scala 3.6.4, JVM (21))
Success connect