Implement debug shell in run cmd

cmd/run.go

@@ -86,7 +86,22 @@ var runCmd = &cobra.Command{
 
 			fmt.Fprintf(os.Stderr, "===========================\n[Network File Share Config]\nThe network file share was started. Please use the credentials below to connect to the file server.\n\nType: "+strings.ToUpper(shareBackendFlag)+"\nURL: %v\nUsername: linsk\nPassword: %v\n===========================\n", shareURI, sharePWD)
 
+			ctxWait := true
+
+			if debugShellFlag {
+				slog.Warn("Starting a debug VM shell")
+				err := runVMShell(ctx, i)
+				if err != nil {
+					slog.Error("Failed to run VM shell", "error", err.Error())
+				} else {
+					ctxWait = false
+				}
+			}
+
+			if ctxWait {
 				<-ctx.Done()
+			}
+
 			return 0
 		}, vmOpts.Ports, unrestrictedNetworkingFlag, vmOpts.EnableTap))
 	},
@@ -99,11 +114,13 @@ var (
 	ftpExtIPFlag           string
 	shareBackendFlag       string
 	smbUseExternAddrFlag   bool
+	debugShellFlag         bool
 )
 
 func init() {
 	runCmd.Flags().BoolVarP(&luksFlag, "luks", "l", false, "Use cryptsetup to open a LUKS volume (password will be prompted).")
 	runCmd.Flags().BoolVar(&allowLUKSLowMemoryFlag, "allow-luks-low-memory", false, "Allow VM memory allocation lower than 2048 MiB when LUKS is enabled.")
+	runCmd.Flags().BoolVar(&debugShellFlag, "debug-shell", false, "Start a VM shell when the network file share is active.")
 
 	var defaultShareType string
 	switch runtime.GOOS {

cmd/shell.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/AlexSSD7/linsk/share"
 	"github.com/AlexSSD7/linsk/vm"
+	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
 	"golang.org/x/crypto/ssh"
 	"golang.org/x/term"
@@ -41,22 +42,40 @@ var shellCmd = &cobra.Command{
 		}
 
 		os.Exit(runVM(passthroughArg, func(ctx context.Context, i *vm.VM, fm *vm.FileManager, trc *share.NetTapRuntimeContext) int {
-			sc, err := i.DialSSH()
+			if trc != nil {
+				slog.Info("Tap networking is active", "host-ip", trc.Net.HostIP, "vm-ip", trc.Net.GuestIP)
+			}
+
+			err := runVMShell(ctx, i)
 			if err != nil {
-				slog.Error("Failed to dial VM SSH", "error", err.Error())
+				slog.Error("Failed to run VM shell", "error", err.Error())
 				return 1
 			}
 
-			if trc != nil {
+			return 0
-				slog.Info("Tap networking is active", "host-ip", trc.Net.HostIP, "vm-ip", trc.Net.GuestIP)
+		}, forwardPortRules, true, enableTapNetFlag))
+	},
+}
+
+var forwardPortsFlagStr string
+var enableTapNetFlag bool
+
+func init() {
+	shellCmd.Flags().StringVar(&forwardPortsFlagStr, "forward-ports", "", "Extra TCP port forwarding rules. Syntax: '<HOST PORT>:<VM PORT>' OR '<HOST BIND IP>:<HOST PORT>:<VM PORT>'. Multiple rules split by comma are accepted.")
+	shellCmd.Flags().BoolVar(&enableTapNetFlag, "enable-net-tap", false, "Enables host-VM tap networking.")
+}
+
+func runVMShell(ctx context.Context, vi *vm.VM) error {
+	sc, err := vi.DialSSH()
+	if err != nil {
+		return errors.Wrap(err, "dial ssh")
 	}
 
 	defer func() { _ = sc.Close() }()
 
 	sess, err := sc.NewSession()
 	if err != nil {
-				slog.Error("Failed to create new VM SSH session", "error", err.Error())
+		return errors.Wrap(err, "new vm ssh session")
-				return 1
 	}
 
 	defer func() { _ = sess.Close() }()
@@ -64,8 +83,7 @@ var shellCmd = &cobra.Command{
 	termFD := int(os.Stdin.Fd())
 	termState, err := term.MakeRaw(termFD)
 	if err != nil {
-				slog.Error("Failed to make raw terminal", "error", err.Error())
+		return errors.Wrap(err, "make raw terminal")
-				return 1
 	}
 
 	defer func() {
@@ -77,14 +95,13 @@ var shellCmd = &cobra.Command{
 
 	termFDGetSize := termFD
 	if runtime.GOOS == "windows" {
-				// Another Windows workaround :/
+		// Workaround for Windows.
 		termFDGetSize = int(os.Stdout.Fd())
 	}
 
 	termWidth, termHeight, err := term.GetSize(termFDGetSize)
 	if err != nil {
-				slog.Error("Failed to get terminal size", "error", err.Error())
+		return errors.Wrap(err, "get terminal size")
-				return 1
 	}
 
 	termModes := ssh.TerminalModes{
@@ -100,8 +117,7 @@ var shellCmd = &cobra.Command{
 
 	err = sess.RequestPty(term, termHeight, termWidth, termModes)
 	if err != nil {
-				slog.Error("Failed to request VM SSH pty", "error", err.Error())
+		return errors.Wrap(err, "request vm ssh pty")
-				return 1
 	}
 
 	sess.Stdin = os.Stdin
@@ -110,8 +126,7 @@ var shellCmd = &cobra.Command{
 
 	err = sess.Shell()
 	if err != nil {
-				slog.Error("Start VM SSH shell", "error", err.Error())
+		return errors.Wrap(err, "start vm ssh shell")
-				return 1
 	}
 
 	doneCh := make(chan struct{}, 1)
@@ -130,15 +145,5 @@ var shellCmd = &cobra.Command{
 	case <-doneCh:
 	}
 
-			return 0
+	return nil
-		}, forwardPortRules, true, enableTapNetFlag))
-	},
-}
-
-var forwardPortsFlagStr string
-var enableTapNetFlag bool
-
-func init() {
-	shellCmd.Flags().StringVar(&forwardPortsFlagStr, "forward-ports", "", "Extra TCP port forwarding rules. Syntax: '<HOST PORT>:<VM PORT>' OR '<HOST BIND IP>:<HOST PORT>:<VM PORT>'. Multiple rules split by comma are accepted.")
-	shellCmd.Flags().BoolVar(&enableTapNetFlag, "enable-net-tap", false, "Enables host-VM tap networking.")
 }