Add graceful shutdown

[bahlo]

Would be great to get graceful shutdown. Right now I'm tokio::select!ing on the future of libunftp::Server.listen and my shutdown future, a.k.a just dropping the everything which isn't great.

[hannesdejager]

Thanks @bahlo . Agreed.

Is there any specific interface you're looking for?

[bahlo]

@hannesdejager Yes, similar to the hyper::Server one.

See also Graceful Shutdown.

[hannesdejager]

@bahlo I'm adding a Server::shutdown_indicator method:

Usage will look something like this:

    let mut server = Server::with_authenticator(storage_backend, Arc::new(authenticator))
        .greeting("Welcome to unFTP")
        .passive_ports(start_port..end_port)
        .idle_session_timeout(idle_timeout)
        .logger(root_log.new(o!("lib" => "libunftp")))
        .passive_host(passive_host)
        .sitemd5(md5_setting)
        .shutdown_indicator(options::Shutdown::GracefulBlockingConnections( async move {
            shutdown.recv().await.ok();
            info!(l, "Shutting down FTP server");
        }))
        .metrics();

Let me know if you have more input.

[hannesdejager]

By the way feel free to share your use case for libunftp. It's always interesting for us :-).

[bahlo]

That looks great, can't wait!

My use case: I have a printer with a scanner on top and I want to use that to scan documents (paperless and all that), but I 1. don't want to upload them to Dropbox or whatever the printer supports unencrypted and 2. don't want to send them via email.

So I use libunftp to expose an FTP server in my local network that, when a file is uploaded will run OCR, store it locally and send a link via email that only resolves locally. That way I can save the document directly to my encrypted storage.

[hannesdejager]

Very nice!

[hannesdejager]

Available in version 0.18.2

[hannesdejager]

Ready for consumption @bahlo :-)

[bahlo]

Thanks, appreciate it! ❤️