Server Package

SSH server implementation for handling Duet connections

Overview

The server package provides the SSH server that handles client connections and manages Bubble Tea sessions for the Duet TUI.

Types

Server

Main server struct that manages SSH connections and room state.

type Server struct {
    addr        string
    hostKeyPath string
    roomManager *room.Manager
    logger      *log.Logger
}

Functions

New

Creates a new Duet server instance.

func New(addr, hostKeyPath, workerURL string) *Server

addr · string · required

The address to listen on (e.g., “localhost:2222”)

hostKeyPath · string · required

Path to the SSH host key file

workerURL · string

Optional URL for the AI worker service. If empty, AI features will be disabled

Returns: A configured *Server instance

Example:

srv := server.New("localhost:2222", ".ssh/duet_ed25519", "http://localhost:8787")

Start

Starts the SSH server and blocks until shutdown.

func (s *Server) Start() error

Returns: Error if the server fails to start or during shutdown

Example:

if err := srv.Start(); err != nil {
    log.Fatal("Server error:", err)
}

Behavior:

• Starts SSH server with Bubble Tea middleware
• Listens for OS interrupt signals (SIGINT, SIGTERM)
• Performs graceful shutdown with 10-second timeout
• Logs server lifecycle events

Implementation Details

SSH Middleware

The server uses Wish middleware for SSH handling:

• Bubble Tea Middleware: Manages TUI sessions
• Logging Middleware: Logs connection events

Session Handling

Each SSH connection:

1. Extracts username (defaults to “guest”)
2. Creates a Bubble Tea renderer
3. Detects terminal type (special handling for xterm-ghostty)
4. Initializes a UI model with the room manager
5. Launches in alternate screen mode

Color Profile Detection

if pty.Term == "xterm-ghostty" {
    renderer.SetColorProfile(termenv.TrueColor)
}

The server automatically enables TrueColor for Ghostty terminal.