feat: Go SSH interactive shell default, --native flag for system SSH

pkg/ssh/client.go

@@ -4,8 +4,13 @@ import (
 	"context"
 	"fmt"
 	"net"
+	"os"
+	"os/signal"
+	"syscall"
 	"time"
 
+	"golang.org/x/term"
+
 	"git.tukangketik.id/swanadiva/hostkeeper/internal/errors"
 	"git.tukangketik.id/swanadiva/hostkeeper/internal/models"
 	cryptossh "golang.org/x/crypto/ssh"
@@ -101,6 +106,83 @@ func (c *Client) Execute(_ context.Context, cmd string) (string, error) {
 	return string(output), nil
 }
 
+// Shell opens an interactive shell session
+func (c *Client) Shell() error {
+	if c.client == nil {
+		return fmt.Errorf("not connected to server")
+	}
+
+	session, err := c.client.NewSession()
+	if err != nil {
+		return fmt.Errorf("failed to create session: %w", err)
+	}
+	defer session.Close()
+
+	// Get current terminal state
+	fd := int(os.Stdin.Fd())
+	oldState, err := term.MakeRaw(fd)
+	if err != nil {
+		return fmt.Errorf("failed to set raw terminal: %w", err)
+	}
+	defer term.Restore(fd, oldState)
+
+	// Set up terminal modes
+	modes := cryptossh.TerminalModes{
+		cryptossh.ECHO:          1,
+		cryptossh.TTY_OP_ISPEED: 14400,
+		cryptossh.TTY_OP_OSPEED: 14400,
+	}
+
+	// Get terminal size
+	width, height, err := term.GetSize(fd)
+	if err != nil {
+		width = 80
+		height = 24
+	}
+
+	// Request PTY
+	if err := session.RequestPty("xterm-256color", height, width, modes); err != nil {
+		return fmt.Errorf("failed to request PTY: %w", err)
+	}
+
+	// Handle window changes
+	sigwinch := make(chan os.Signal, 1)
+	signal.Notify(sigwinch, os.Signal(syscall.SIGWINCH))
+	go func() {
+		for range sigwinch {
+			w, h, err := term.GetSize(fd)
+			if err != nil {
+				continue
+			}
+			session.WindowChange(h, w)
+		}
+	}()
+	defer signal.Stop(sigwinch)
+
+	// Link I/O
+	session.Stdin = os.Stdin
+	session.Stdout = os.Stdout
+	session.Stderr = os.Stderr
+
+	// Start shell
+	if err := session.Shell(); err != nil {
+		return fmt.Errorf("failed to start shell: %w", err)
+	}
+
+	// Wait for shell to exit
+	if err := session.Wait(); err != nil {
+		if exitErr, ok := err.(*cryptossh.ExitError); ok {
+			if exitErr.ExitStatus() != 0 {
+				return fmt.Errorf("shell exited with status %d", exitErr.ExitStatus())
+			}
+			return nil
+		}
+		return fmt.Errorf("shell session error: %w", err)
+	}
+
+	return nil
+}
+
 // Close closes the SSH connection
 func (c *Client) Close() error {
 	if c.client != nil {