Many minor fixes/improvements

cmd/imgbuilder/builder/build.go

@@ -88,7 +88,7 @@ func (bc *BuildContext) BuildWithInterruptHandler() error {
 	defer func() {
 		err := bc.vi.Cancel()
 		if err != nil {
-			bc.logger.Error("Failed to cancel VM context", "error", err)
+			bc.logger.Error("Failed to cancel VM context", "error", err.Error())
 		}
 	}()
 
@@ -129,7 +129,7 @@ func (bc *BuildContext) BuildWithInterruptHandler() error {
 
 				err := bc.vi.Cancel()
 				if err != nil {
-					lg.Warn("Failed to cancel VM context", "error", err)
+					lg.Warn("Failed to cancel VM context", "error", err.Error())
 				}
 			}
 		}

cmd/imgbuilder/main.go

@@ -19,13 +19,13 @@ var rootCmd = &cobra.Command{
 
 		bc, err := builder.NewBuildContext(slog.With("caller", "build-context"), baseISOPath, outImagePath, vmDebugFlag)
 		if err != nil {
-			slog.Error("Failed to create a new build context", "error", err)
+			slog.Error("Failed to create a new build context", "error", err.Error())
 			os.Exit(1)
 		}
 
 		err = bc.BuildWithInterruptHandler()
 		if err != nil {
-			slog.Error("Failed to build an image", "error", err)
+			slog.Error("Failed to build an image", "error", err.Error())
 			os.Exit(1)
 		}
 

cmd/ls.go

@@ -20,11 +20,16 @@ var lsCmd = &cobra.Command{
 		os.Exit(runVM(args[0], func(ctx context.Context, i *vm.VM, fm *vm.FileManager) int {
 			lsblkOut, err := fm.Lsblk()
 			if err != nil {
-				slog.Error("Failed to list block devices in the VM", "error", err)
+				slog.Error("Failed to list block devices in the VM", "error", err.Error())
 				return 1
 			}
 
-			fmt.Print(string(lsblkOut))
+			if len(lsblkOut) == 0 {
+				fmt.Printf("<empty lsblk output>\n")
+			} else {
+				fmt.Print(string(lsblkOut))
+			}
+
 			return 0
 		}, nil, false))
 	},

cmd/root.go

@@ -26,6 +26,9 @@ func Execute() {
 
 var vmDebugFlag bool
 var unrestrictedNetworkingFlag bool
+var vmMemAllocFlag uint64
+
+// TODO: Version command.
 
 func init() {
 	slog.SetDefault(slog.New(slog.NewTextHandler(os.Stderr, nil)))
@@ -34,6 +37,7 @@ func init() {
 	rootCmd.AddCommand(runCmd)
 	rootCmd.AddCommand(shellCmd)
 
-	rootCmd.PersistentFlags().BoolVar(&vmDebugFlag, "vmdebug", false, "Enable VM debug mode. This will open an accessible VM monitor. You can log in with root user and no password.")
+	rootCmd.PersistentFlags().BoolVar(&vmDebugFlag, "vmdebug", false, "Enables the VM debug mode. This will open an accessible VM monitor. You can log in with root user and no password.")
-	rootCmd.PersistentFlags().BoolVar(&unrestrictedNetworkingFlag, "unrestricted-networking", false, "Enable unrestricted networking. This will allow the VM to connect to the internet.")
+	rootCmd.PersistentFlags().BoolVar(&unrestrictedNetworkingFlag, "unrestricted-networking", false, "Enables unrestricted networking. This will allow the VM to connect to the internet.")
+	rootCmd.PersistentFlags().Uint64Var(&vmMemAllocFlag, "vm-mem-alloc", 512, "Specifies the VM memory allocation in KiB")
 }

cmd/run.go

@@ -24,7 +24,7 @@ var runCmd = &cobra.Command{
 
 		networkSharePort, err := getClosestAvailPortWithSubsequent(9000, 10)
 		if err != nil {
-			slog.Error("Failed to get closest available host port for network file share", "error", err)
+			slog.Error("Failed to get closest available host port for network file share", "error", err.Error())
 			os.Exit(1)
 		}
 
@@ -46,18 +46,20 @@ var runCmd = &cobra.Command{
 		// TODO: `slog` library prints entire stack traces for errors which makes reading errors challenging.
 
 		os.Exit(runVM(args[0], func(ctx context.Context, i *vm.VM, fm *vm.FileManager) int {
+			slog.Info("Mounting the device", "dev", vmMountDevName, "fs", fsType, "luks", luksFlag)
+
 			err := fm.Mount(vmMountDevName, vm.MountOptions{
 				FSType: fsType,
 				LUKS:   luksFlag,
 			})
 			if err != nil {
-				slog.Error("Failed to mount the disk inside the VM", "error", err)
+				slog.Error("Failed to mount the disk inside the VM", "error", err.Error())
 				return 1
 			}
 
 			sharePWD, err := password.Generate(16, 10, 0, false, false)
 			if err != nil {
-				slog.Error("Failed to generate ephemeral password for network file share", "error", err)
+				slog.Error("Failed to generate ephemeral password for network file share", "error", err.Error())
 				return 1
 			}
 
@@ -67,7 +69,7 @@ var runCmd = &cobra.Command{
 
 			err = fm.StartFTP([]byte(sharePWD), networkSharePort+1, ftpPassivePortCount)
 			if err != nil {
-				slog.Error("Failed to start FTP server", "error", err)
+				slog.Error("Failed to start FTP server", "error", err.Error())
 				return 1
 			}
 

cmd/shell.go

@@ -32,7 +32,7 @@ var shellCmd = &cobra.Command{
 
 			fpr, err := vm.ParsePortForwardString(fp)
 			if err != nil {
-				slog.Error("Failed to parse port forward string", "index", i, "value", fp, "error", err)
+				slog.Error("Failed to parse port forward string", "index", i, "value", fp, "error", err.Error())
 				os.Exit(1)
 			}
 
@@ -42,7 +42,7 @@ var shellCmd = &cobra.Command{
 		os.Exit(runVM(passthroughArg, func(ctx context.Context, i *vm.VM, fm *vm.FileManager) int {
 			sc, err := i.DialSSH()
 			if err != nil {
-				slog.Error("Failed to dial VM SSH", "error", err)
+				slog.Error("Failed to dial VM SSH", "error", err.Error())
 				return 1
 			}
 
@@ -50,7 +50,7 @@ var shellCmd = &cobra.Command{
 
 			sess, err := sc.NewSession()
 			if err != nil {
-				slog.Error("Failed to create new VM SSH session", "error", err)
+				slog.Error("Failed to create new VM SSH session", "error", err.Error())
 				return 1
 			}
 
@@ -59,14 +59,14 @@ 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)
+				slog.Error("Failed to make raw terminal", "error", err.Error())
 				return 1
 			}
 
 			defer func() {
 				err := term.Restore(termFD, termState)
 				if err != nil {
-					slog.Error("Failed to restore terminal", "error", err)
+					slog.Error("Failed to restore terminal", "error", err.Error())
 				}
 			}()
 
@@ -78,7 +78,7 @@ var shellCmd = &cobra.Command{
 
 			termWidth, termHeight, err := term.GetSize(termFDGetSize)
 			if err != nil {
-				slog.Error("Failed to get terminal size", "error", err)
+				slog.Error("Failed to get terminal size", "error", err.Error())
 				return 1
 			}
 
@@ -95,7 +95,7 @@ var shellCmd = &cobra.Command{
 
 			err = sess.RequestPty(term, termHeight, termWidth, termModes)
 			if err != nil {
-				slog.Error("Failed to request VM SSH pty", "error", err)
+				slog.Error("Failed to request VM SSH pty", "error", err.Error())
 				return 1
 			}
 
@@ -105,7 +105,7 @@ var shellCmd = &cobra.Command{
 
 			err = sess.Shell()
 			if err != nil {
-				slog.Error("Start VM SSH shell", "error", err)
+				slog.Error("Start VM SSH shell", "error", err.Error())
 				return 1
 			}
 
@@ -114,7 +114,7 @@ var shellCmd = &cobra.Command{
 			go func() {
 				err = sess.Wait()
 				if err != nil {
-					slog.Error("Failed to wait for VM SSH session to finish", "error", err)
+					slog.Error("Failed to wait for VM SSH session to finish", "error", err.Error())
 				}
 
 				doneCh <- struct{}{}

cmd/utils.go

@@ -40,7 +40,7 @@ func doUSBRootCheck() {
 
 	ok, err := checkIfRoot()
 	if err != nil {
-		slog.Error("Failed to check whether the command is ran by root", "error", err)
+		slog.Error("Failed to check whether the command is ran by root", "error", err.Error())
 		os.Exit(1)
 	}
 
@@ -64,6 +64,8 @@ func runVM(passthroughArg string, fn func(context.Context, *vm.VM, *vm.FileManag
 			SnapshotMode: true,
 		}},
 
+		MemoryAlloc: vmMemAllocFlag,
+
 		USBDevices:               passthroughConfig,
 		ExtraPortForwardingRules: forwardPortsRules,
 
@@ -74,7 +76,7 @@ func runVM(passthroughArg string, fn func(context.Context, *vm.VM, *vm.FileManag
 	// TODO: Alpine image should be downloaded from somewhere.
 	vi, err := vm.NewVM(slog.Default().With("caller", "vm"), vmCfg)
 	if err != nil {
-		slog.Error("Failed to create vm instance", "error", err)
+		slog.Error("Failed to create vm instance", "error", err.Error())
 		os.Exit(1)
 	}
 
@@ -115,7 +117,7 @@ func runVM(passthroughArg string, fn func(context.Context, *vm.VM, *vm.FileManag
 
 				err := vi.Cancel()
 				if err != nil {
-					lg.Warn("Failed to cancel VM context", "error", err)
+					lg.Warn("Failed to cancel VM context", "error", err.Error())
 				}
 			}
 		}
@@ -130,12 +132,12 @@ func runVM(passthroughArg string, fn func(context.Context, *vm.VM, *vm.FileManag
 				err = fmt.Errorf("operation canceled by user")
 			}
 
-			slog.Error("Failed to start the VM", "error", err)
+			slog.Error("Failed to start the VM", "error", err.Error())
 			os.Exit(1)
 		case <-vi.SSHUpNotifyChan():
 			err := fm.Init()
 			if err != nil {
-				slog.Error("Failed to initialize File Manager", "error", err)
+				slog.Error("Failed to initialize File Manager", "error", err.Error())
 				os.Exit(1)
 			}
 
@@ -143,7 +145,7 @@ func runVM(passthroughArg string, fn func(context.Context, *vm.VM, *vm.FileManag
 
 			err = vi.Cancel()
 			if err != nil {
-				slog.Error("Failed to cancel VM context", "error", err)
+				slog.Error("Failed to cancel VM context", "error", err.Error())
 				os.Exit(1)
 			}
 
@@ -152,7 +154,7 @@ func runVM(passthroughArg string, fn func(context.Context, *vm.VM, *vm.FileManag
 			select {
 			case err := <-runErrCh:
 				if err != nil {
-					slog.Error("Failed to run the VM", "error", err)
+					slog.Error("Failed to run the VM", "error", err.Error())
 					os.Exit(1)
 				}
 			default:

vm/filemanager.go

@@ -40,11 +40,6 @@ func (fm *FileManager) Init() error {
 
 	defer func() { _ = sc.Close() }()
 
-	_, err = runSSHCmd(sc, "apk add util-linux lvm2")
-	if err != nil {
-		return errors.Wrap(err, "install utilities")
-	}
-
 	_, err = runSSHCmd(sc, "vgchange -ay")
 	if err != nil {
 		return errors.Wrap(err, "run vgchange cmd")
@@ -110,7 +105,7 @@ func (fm *FileManager) luksOpen(sc *ssh.Client, fullDevPath string) error {
 		return errors.Wrap(err, "start cryptsetup luksopen cmd")
 	}
 
-	lg.Info("Attempting to open LUKS device")
+	lg.Info("Attempting to open a LUKS device")
 
 	_, err = os.Stderr.Write([]byte("Enter Password: "))
 	if err != nil {
@@ -140,6 +135,10 @@ func (fm *FileManager) luksOpen(sc *ssh.Client, fullDevPath string) error {
 
 	err = sess.Wait()
 	if err != nil {
+		if strings.Contains(stderrBuf.String(), "Not enough available memory to open a keyslot.") {
+			fm.logger.Warn("Detected not enough memory to open a LUKS device, please allocate more memory using --vm-mem-alloc flag.")
+		}
+
 		return utils.WrapErrWithLog(err, "wait for cryptsetup luksopen cmd to finish", stderrBuf.String())
 	}
 
@@ -268,11 +267,11 @@ pasv_address=127.0.0.1
 	go func() {
 		_, err = stdinPipe.Write(pwd)
 		if err != nil {
-			fm.vm.logger.Error("Failed to write FTP password to passwd stdin", "error", err)
+			fm.vm.logger.Error("Failed to write FTP password to passwd stdin", "error", err.Error())
 		}
 		_, err = stdinPipe.Write(pwd)
 		if err != nil {
-			fm.vm.logger.Error("Failed to write repeated FTP password to passwd stdin", "error", err)
+			fm.vm.logger.Error("Failed to write repeated FTP password to passwd stdin", "error", err.Error())
 		}
 	}()
 

vm/vm.go

@@ -61,6 +61,8 @@ type VMConfig struct {
 	CdromImagePath string
 	Drives         []DriveConfig
 
+	MemoryAlloc uint64 // In KiB.
+
 	USBDevices               []USBDevicePassthroughConfig
 	ExtraPortForwardingRules []PortForwardingRule
 
@@ -84,7 +86,7 @@ func NewVM(logger *slog.Logger, cfg VMConfig) (*VM, error) {
 
 	// TODO: Configurable memory allocation
 
-	cmdArgs := []string{"-serial", "stdio", "-m", "2048", "-smp", fmt.Sprint(runtime.NumCPU())}
+	cmdArgs := []string{"-serial", "stdio", "-m", fmt.Sprint(cfg.MemoryAlloc), "-smp", fmt.Sprint(runtime.NumCPU())}
 
 	baseCmd := "qemu-system"
 
@@ -319,14 +321,14 @@ func (vm *VM) Cancel() error {
 	sc, err := vm.DialSSH()
 	if err != nil {
 		if !errors.Is(err, ErrSSHUnavailable) {
-			vm.logger.Warn("Failed to dial VM SSH to do graceful shutdown", "error", err)
+			vm.logger.Warn("Failed to dial VM SSH to do graceful shutdown", "error", err.Error())
 		}
 	} else {
 		vm.logger.Warn("Sending poweroff command to the VM")
 		_, err = runSSHCmd(sc, "poweroff")
 		_ = sc.Close()
 		if err != nil {
-			vm.logger.Warn("Could not power off the VM safely", "error", err)
+			vm.logger.Warn("Could not power off the VM safely", "error", err.Error())
 		} else {
 			vm.logger.Info("Shutting the VM down safely")
 		}