update examples to new APIs

Author: ricott1

russh/examples/ratatui_app.rs

@@ -0,0 +1,212 @@
+use async_trait::async_trait;
+use ratatui::{
+    backend::CrosstermBackend,
+    layout::Rect,
+    style::{Color, Style},
+    widgets::{Block, Borders, Clear, Paragraph},
+    Terminal,
+};
+use russh::{server::*, Channel, ChannelId};
+use russh_keys::key::PublicKey;
+use std::collections::HashMap;
+use std::sync::Arc;
+use tokio::sync::Mutex;
+
+type SshTerminal = Terminal<CrosstermBackend<TerminalHandle>>;
+
+struct App {
+    pub counter: usize,
+}
+
+impl App {
+    pub fn new() -> App {
+        Self { counter: 0 }
+    }
+}
+
+#[derive(Clone)]
+struct TerminalHandle {
+    handle: Handle,
+    // The sink collects the data which is finally flushed to the handle.
+    sink: Vec<u8>,
+    channel_id: ChannelId,
+}
+
+// The crossterm backend writes to the terminal handle.
+impl std::io::Write for TerminalHandle {
+    fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
+        self.sink.extend_from_slice(buf);
+        Ok(buf.len())
+    }
+
+    fn flush(&mut self) -> std::io::Result<()> {
+        let handle = self.handle.clone();
+        let channel_id = self.channel_id.clone();
+        let data = self.sink.clone().into();
+        futures::executor::block_on(async move {
+            let result = handle.data(channel_id, data).await;
+            if result.is_err() {
+                eprintln!("Failed to send data: {:?}", result);
+            }
+        });
+
+        self.sink.clear();
+        Ok(())
+    }
+}
+
+#[derive(Clone)]
+struct AppServer {
+    clients: Arc<Mutex<HashMap<usize, (SshTerminal, App)>>>,
+    id: usize,
+}
+
+impl AppServer {
+    pub fn new() -> Self {
+        Self {
+            clients: Arc::new(Mutex::new(HashMap::new())),
+            id: 0,
+        }
+    }
+
+    pub async fn run(&mut self) -> Result<(), anyhow::Error> {
+        let clients = self.clients.clone();
+        tokio::spawn(async move {
+            loop {
+                tokio::time::sleep(tokio::time::Duration::from_secs(1)).await;
+
+                for (_, (terminal, app)) in clients.lock().await.iter_mut() {
+                    app.counter += 1;
+
+                    terminal
+                        .draw(|f| {
+                            let size = f.size();
+                            f.render_widget(Clear, size);
+                            let style = match app.counter % 3 {
+                                0 => Style::default().fg(Color::Red),
+                                1 => Style::default().fg(Color::Green),
+                                _ => Style::default().fg(Color::Blue),
+                            };
+                            let paragraph = Paragraph::new(format!("Counter: {}", app.counter))
+                                .alignment(ratatui::layout::Alignment::Center)
+                                .style(style);
+                            let block = Block::default()
+                                .title("Press 'c' to reset the counter!")
+                                .borders(Borders::ALL);
+                            f.render_widget(paragraph.block(block), size);
+                        })
+                        .unwrap();
+                }
+            }
+        });
+
+        let config = Config {
+            inactivity_timeout: Some(std::time::Duration::from_secs(3600)),
+            auth_rejection_time: std::time::Duration::from_secs(3),
+            auth_rejection_time_initial: Some(std::time::Duration::from_secs(0)),
+            keys: vec![russh_keys::key::KeyPair::generate_ed25519().unwrap()],
+            ..Default::default()
+        };
+
+        self.run_on_address(Arc::new(config), ("0.0.0.0", 2222))
+            .await?;
+        Ok(())
+    }
+}
+
+impl Server for AppServer {
+    type Handler = Self;
+    fn new_client(&mut self, _: Option<std::net::SocketAddr>) -> Self {
+        let s = self.clone();
+        self.id += 1;
+        s
+    }
+}
+
+#[async_trait]
+impl Handler for AppServer {
+    type Error = anyhow::Error;
+
+    async fn channel_open_session(
+        &mut self,
+        channel: Channel<Msg>,
+        session: &mut Session,
+    ) -> Result<bool, Self::Error> {
+        {
+            let mut clients = self.clients.lock().await;
+            let terminal_handle = TerminalHandle {
+                handle: session.handle(),
+                sink: Vec::new(),
+                channel_id: channel.id(),
+            };
+
+            let backend = CrosstermBackend::new(terminal_handle.clone());
+            let terminal = Terminal::new(backend)?;
+            let app = App::new();
+
+            clients.insert(self.id, (terminal, app));
+        }
+
+        Ok(true)
+    }
+
+    async fn auth_publickey(&mut self, _: &str, _: &PublicKey) -> Result<Auth, Self::Error> {
+        Ok(Auth::Accept)
+    }
+
+    async fn data(
+        &mut self,
+        channel: ChannelId,
+        data: &[u8],
+        session: &mut Session,
+    ) -> Result<(), Self::Error> {
+        match data {
+            // Pressing 'q' closes the connection.
+            b"q" => {
+                self.clients.lock().await.remove(&self.id);
+                session.close(channel);
+            }
+            // Pressing 'c' resets the counter for the app.
+            // Only the client with the id sees the counter reset.
+            b"c" => {
+                let mut clients = self.clients.lock().await;
+                let (_, app) = clients.get_mut(&self.id).unwrap();
+                app.counter = 0;
+            }
+            _ => {}
+        }
+
+        Ok(())
+    }
+
+    /// The client's window size has changed.
+    async fn window_change_request(
+        &mut self,
+        _: ChannelId,
+        col_width: u32,
+        row_height: u32,
+        _: u32,
+        _: u32,
+        _: &mut Session,
+    ) -> Result<(), Self::Error> {
+        {
+            let mut clients = self.clients.lock().await;
+            let (terminal, _) = clients.get_mut(&self.id).unwrap();
+            let rect = Rect {
+                x: 0,
+                y: 0,
+                width: col_width as u16,
+                height: row_height as u16,
+            };
+            terminal.resize(rect)?;
+        }
+
+        Ok(())
+    }
+}
+
+#[tokio::main]
+async fn main() {
+    let mut server = AppServer::new();
+    server.run().await.expect("Failed running server");
+}