How to replicate files from FTP  to local file system  with Apache NiFi 

   
    For tests we need SFTP server. In my case I created it on Google cloud. To do this we need to create compute engine based on Cent OS (because CentOS has built in sftp server)

     After creating compute instance login using browser pop-up based terminal.

     In opened terminal window create user sudo adduser myuser 

and set password sudo passwd yourpass.

   Then open sshd config for editing sudo vi /etc/ssh/sshd_config and uncomment PasswordAuthentication yes. Then simply stop and start compute engine.

   Next step is to create NiFi workflow. Just add processes on the canvas like on screen below and connect them.

    

   Then open ListFiles processor and set host, username, password, path to source directory

    

   Open Fetch Processor and configure ftp host and credentials. Set file path property

    

    Configure PutFile processor which responsible for storing files on local filesystem

    

That's all. Now we can start workflow by pressing run button on control panel.