Implement shell command

cmd/shell.go

@@ -0,0 +1,110 @@
+package cmd
+
+import (
+	"context"
+	"log/slog"
+	"os"
+
+	"github.com/AlexSSD7/linsk/vm"
+	"github.com/spf13/cobra"
+	"golang.org/x/crypto/ssh"
+	"golang.org/x/term"
+)
+
+var shellCmd = &cobra.Command{
+	Use: "shell",
+	// TODO: Fill this
+	// Short: "",
+	Args: cobra.RangeArgs(0, 1),
+	RunE: func(cmd *cobra.Command, args []string) error {
+		var passthroughArg string
+		if len(args) > 0 {
+			passthroughArg = args[0]
+		}
+
+		os.Exit(runVM(passthroughArg, func(ctx context.Context, i *vm.Instance, fm *vm.FileManager) int {
+			sc, err := i.DialSSH()
+			if err != nil {
+				slog.Error("Failed to dial VM SSH", "error", err)
+				return 1
+			}
+
+			defer func() { _ = sc.Close() }()
+
+			sess, err := sc.NewSession()
+			if err != nil {
+				slog.Error("Failed to create new VM SSH session", "error", err)
+				return 1
+			}
+
+			defer func() { _ = sess.Close() }()
+
+			termFD := int(os.Stdin.Fd())
+			termState, err := term.MakeRaw(termFD)
+			if err != nil {
+				slog.Error("Failed to make raw terminal", "error", err)
+				return 1
+			}
+
+			defer func() {
+				err := term.Restore(termFD, termState)
+				if err != nil {
+					slog.Error("Failed to restore terminal", "error", err)
+				}
+			}()
+
+			termWidth, termHeight, err := term.GetSize(termFD)
+			if err != nil {
+				slog.Error("Failed to get terminal size", "error", err)
+				return 1
+			}
+
+			termModes := ssh.TerminalModes{
+				ssh.ECHO:          1,
+				ssh.TTY_OP_ISPEED: 14400,
+				ssh.TTY_OP_OSPEED: 14400,
+			}
+
+			term := os.Getenv("TERM")
+			if term == "" {
+				term = "xterm-256color"
+			}
+
+			err = sess.RequestPty(term, termHeight, termWidth, termModes)
+			if err != nil {
+				slog.Error("Failed to request VM SSH pty", "error", err)
+				return 1
+			}
+
+			sess.Stdin = os.Stdin
+			sess.Stdout = os.Stdout
+			sess.Stderr = os.Stderr
+
+			err = sess.Shell()
+			if err != nil {
+				slog.Error("Start VM SSH shell", "error", err)
+				return 1
+			}
+
+			doneCh := make(chan struct{}, 1)
+
+			go func() {
+				err = sess.Wait()
+				if err != nil {
+					slog.Error("Failed to wait for VM SSH session to finish", "error", err)
+				}
+
+				doneCh <- struct{}{}
+			}()
+
+			select {
+			case <-ctx.Done():
+			case <-doneCh:
+			}
+
+			return 0
+		}))
+
+		return nil
+	},
+}