Receive File via SFTP/SSH and automatically forward to FTP on another server

Question

I'm currently in a situation where I receive flat files via FTP from my clients. A couple of clients have insisted on the need to use SSH Private Key SFTP rather than regular FTP.

What I want to do is setup a web server (preferably in linux/unix but I guess I can do it on a windows server and purchase SFTP server software) that will do the following:

1. Allow me to setup an SFTP directory for each client with unique user/pass. Each directory also has to have the public/private key SSH "stuff" I'm a little new to this but I've googled it.

2. Once the file is completely uploaded by the client, I want to kick off an event that ftp's that file via regular FTP to my Windows cloud.

3. These files can be up to 10mb so the even that ftp's to the other server can't fire until the file is completely uploaded.

Has anyone set something like this up? Any guidance would be appreciated.

Thanks!

Answer 1

In Linux, you can use incron to monitor the directory the files will be SFTP'd to and have it trigger your ftp job. It's kind of like cron except that instead of triggering jobs based on time, it does so based on filesystem modifications. In order to only trigger once the entire file has been written, I think you can use IN_CLOSE_WRITE in the inotify mask. Failing this, I suggest configuring events for each of the events individually to echo a message to a log file and see if you can identify one which reliably happens only at the end of the SFTP transfer.

If you're using RedHat, it's not in the standard distribution, but it is in EPEL.