Make guest username, uid, home directory configurable

Also disallows the "admin" username by default (because it is a builtin
user in Ubuntu), but can be overridden by setting it explicitly in lima.yaml.

Signed-off-by: Jan Dubois <[email protected]>

Author: jandubois

.golangci.yml

@@ -121,6 +121,9 @@ linters-settings:
     - name: context-keys-type
     - name: deep-exit
     - name: dot-imports
+      arguments:
+      - allowedPackages:
+        - github.com/lima-vm/lima/pkg/must
     - name: empty-block
     - name: error-naming
     - name: error-return

cmd/limactl/copy.go

@@ -8,7 +8,6 @@ import (
 	"strings"
 
 	"github.com/coreos/go-semver/semver"
-	"github.com/lima-vm/lima/pkg/osutil"
 	"github.com/lima-vm/lima/pkg/sshutil"
 	"github.com/lima-vm/lima/pkg/store"
 	"github.com/sirupsen/logrus"
@@ -48,11 +47,7 @@ func copyAction(cmd *cobra.Command, args []string) error {
 	if err != nil {
 		return err
 	}
-	u, err := osutil.LimaUser(false)
-	if err != nil {
-		return err
-	}
-	instDirs := make(map[string]string)
+	instances := make(map[string]*store.Instance)
 	scpFlags := []string{}
 	scpArgs := []string{}
 	debug, err := cmd.Flags().GetBool("debug")
@@ -85,28 +80,28 @@ func copyAction(cmd *cobra.Command, args []string) error {
 			}
 			if legacySSH {
 				scpFlags = append(scpFlags, "-P", fmt.Sprintf("%d", inst.SSHLocalPort))
-				scpArgs = append(scpArgs, fmt.Sprintf("%[email protected]:%s", u.Username, path[1]))
+				scpArgs = append(scpArgs, fmt.Sprintf("%[email protected]:%s", *inst.Config.User.Username, path[1]))
 			} else {
-				scpArgs = append(scpArgs, fmt.Sprintf("scp://%[email protected]:%d/%s", u.Username, inst.SSHLocalPort, path[1]))
+				scpArgs = append(scpArgs, fmt.Sprintf("scp://%[email protected]:%d/%s", *inst.Config.User.Username, inst.SSHLocalPort, path[1]))
 			}
-			instDirs[instName] = inst.Dir
+			instances[instName] = inst
 		default:
 			return fmt.Errorf("path %q contains multiple colons", arg)
 		}
 	}
-	if legacySSH && len(instDirs) > 1 {
+	if legacySSH && len(instances) > 1 {
 		return fmt.Errorf("more than one (instance) host is involved in this command, this is only supported for openSSH v8.0 or higher")
 	}
 	scpFlags = append(scpFlags, "-3", "--")
 	scpArgs = append(scpFlags, scpArgs...)
 
 	var sshOpts []string
-	if len(instDirs) == 1 {
+	if len(instances) == 1 {
 		// Only one (instance) host is involved; we can use the instance-specific
 		// arguments such as ControlPath.  This is preferred as we can multiplex
 		// sessions without re-authenticating (MaxSessions permitting).
-		for _, instDir := range instDirs {
-			sshOpts, err = sshutil.SSHOpts(instDir, false, false, false, false)
+		for _, inst := range instances {
+			sshOpts, err = sshutil.SSHOpts(inst.Dir, *inst.Config.User.Username, false, false, false, false)
 			if err != nil {
 				return err
 			}

cmd/limactl/shell.go

@@ -167,6 +167,7 @@ func shellAction(cmd *cobra.Command, args []string) error {
 
 	sshOpts, err := sshutil.SSHOpts(
 		inst.Dir,
+		*inst.Config.User.Username,
 		*inst.Config.SSH.LoadDotSSHPubKeys,
 		*inst.Config.SSH.ForwardAgent,
 		*inst.Config.SSH.ForwardX11,

cmd/limactl/show-ssh.go

@@ -90,6 +90,7 @@ func showSSHAction(cmd *cobra.Command, args []string) error {
 		filepath.Join(inst.Dir, filenames.SSHConfig), inst.Hostname)
 	opts, err := sshutil.SSHOpts(
 		inst.Dir,
+		*inst.Config.User.Username,
 		*inst.Config.SSH.LoadDotSSHPubKeys,
 		*inst.Config.SSH.ForwardAgent,
 		*inst.Config.SSH.ForwardX11,

cmd/limactl/tunnel.go

@@ -107,6 +107,7 @@ func tunnelAction(cmd *cobra.Command, args []string) error {
 
 	sshOpts, err := sshutil.SSHOpts(
 		inst.Dir,
+		*inst.Config.User.Username,
 		*inst.Config.SSH.LoadDotSSHPubKeys,
 		*inst.Config.SSH.ForwardAgent,
 		*inst.Config.SSH.ForwardX11,

pkg/cidata/cidata.go

@@ -117,11 +117,7 @@ func templateArgs(bootScripts bool, instDir, name string, instConfig *limayaml.L
 	if err := limayaml.Validate(instConfig, false); err != nil {
 		return nil, err
 	}
-	u, err := osutil.LimaUser(true)
-	if err != nil {
-		return nil, err
-	}
-	uid, err := strconv.Atoi(u.Uid)
+	uid, err := strconv.Atoi(*instConfig.User.UID)
 	if err != nil {
 		return nil, err
 	}
@@ -130,9 +126,9 @@ func templateArgs(bootScripts bool, instDir, name string, instConfig *limayaml.L
 		BootScripts:        bootScripts,
 		Name:               name,
 		Hostname:           identifierutil.HostnameFromInstName(name), // TODO: support customization
-		User:               u.Username,
 		UID:                uid,
-		Home:               fmt.Sprintf("/home/%s.linux", u.Username),
+		User:               *instConfig.User.Username,
+		Home:               *instConfig.User.HomeDir,
 		GuestInstallPrefix: *instConfig.GuestInstallPrefix,
 		UpgradePackages:    *instConfig.UpgradePackages,
 		Containerd:         Containerd{System: *instConfig.Containerd.System, User: *instConfig.Containerd.User},

pkg/cidata/template.go

@@ -11,7 +11,6 @@ import (
 	"github.com/lima-vm/lima/pkg/iso9660util"
 
 	"github.com/containerd/containerd/identifiers"
-	"github.com/lima-vm/lima/pkg/osutil"
 	"github.com/lima-vm/lima/pkg/textutil"
 )
 
@@ -96,9 +95,8 @@ func ValidateTemplateArgs(args *TemplateArgs) error {
 	if err := identifiers.Validate(args.Name); err != nil {
 		return err
 	}
-	if !osutil.ValidateUsername(args.User) {
-		return errors.New("field User must be valid linux username")
-	}
+	// args.User is intentionally not validated here; the user can override with any name they want
+	// limayaml.FillDefault will validate the default (local) username, but not an explicit setting
 	if args.User == "root" {
 		return errors.New("field User must not be \"root\"")
 	}

pkg/hostagent/hostagent.go

@@ -144,6 +144,7 @@ func New(instName string, stdout io.Writer, signalCh chan os.Signal, opts ...Opt
 
 	sshOpts, err := sshutil.SSHOpts(
 		inst.Dir,
+		*inst.Config.User.Username,
 		*inst.Config.SSH.LoadDotSSHPubKeys,
 		*inst.Config.SSH.ForwardAgent,
 		*inst.Config.SSH.ForwardX11,
@@ -182,13 +183,13 @@ func New(instName string, stdout io.Writer, signalCh chan os.Signal, opts ...Opt
 	// Block ports 22 and sshLocalPort on all IPs
 	for _, port := range []int{sshGuestPort, sshLocalPort} {
 		rule := limayaml.PortForward{GuestIP: net.IPv4zero, GuestPort: port, Ignore: true}
-		limayaml.FillPortForwardDefaults(&rule, inst.Dir, inst.Param)
+		limayaml.FillPortForwardDefaults(&rule, inst.Dir, inst.Config.User, inst.Param)
 		rules = append(rules, rule)
 	}
 	rules = append(rules, inst.Config.PortForwards...)
 	// Default forwards for all non-privileged ports from "127.0.0.1" and "::1"
 	rule := limayaml.PortForward{}
-	limayaml.FillPortForwardDefaults(&rule, inst.Dir, inst.Param)
+	limayaml.FillPortForwardDefaults(&rule, inst.Dir, inst.Config.User, inst.Param)
 	rules = append(rules, rule)
 
 	limaDriver := driverutil.CreateTargetDriverInstance(&driver.BaseDriver{

pkg/instance/create.go

@@ -41,7 +41,7 @@ func Create(ctx context.Context, instName string, instConfig []byte, saveBrokenY
 	}
 	// limayaml.Load() needs to pass the store file path to limayaml.FillDefault() to calculate default MAC addresses
 	filePath := filepath.Join(instDir, filenames.LimaYAML)
-	loadedInstConfig, err := limayaml.Load(instConfig, filePath)
+	loadedInstConfig, err := limayaml.LoadWithWarnings(instConfig, filePath)
 	if err != nil {
 		return nil, err
 	}

pkg/limayaml/defaults.go

@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"net"
 	"os"
+	"os/user"
 	"path/filepath"
 	"runtime"
 	"slices"
@@ -18,11 +19,13 @@ import (
 	"github.com/coreos/go-semver/semver"
 	"github.com/docker/go-units"
 	"github.com/goccy/go-yaml"
+	"github.com/lima-vm/lima/pkg/version"
 	"github.com/pbnjay/memory"
 	"github.com/sirupsen/logrus"
 	"golang.org/x/sys/cpu"
 
 	"github.com/lima-vm/lima/pkg/identifierutil"
+	. "github.com/lima-vm/lima/pkg/must"
 	"github.com/lima-vm/lima/pkg/networks"
 	"github.com/lima-vm/lima/pkg/osutil"
 	"github.com/lima-vm/lima/pkg/ptr"
@@ -43,7 +46,12 @@ const (
 	DefaultVirtiofsQueueSize int = 1024
 )
 
-var IPv4loopback1 = net.IPv4(127, 0, 0, 1)
+var (
+	IPv4loopback1 = net.IPv4(127, 0, 0, 1)
+
+	userHomeDir = Must(os.UserHomeDir())
+	currentUser = Must(user.Current())
+)
 
 func defaultCPUType() CPUType {
 	cpuType := map[Arch]string{
@@ -171,17 +179,58 @@ func defaultGuestInstallPrefix() string {
 //   - Networks are appended in d, y, o order
 //   - DNS are picked from the highest priority where DNS is not empty.
 //   - CACertificates Files and Certs are uniquely appended in d, y, o order
-func FillDefault(y, d, o *LimaYAML, filePath string) {
+func FillDefault(y, d, o *LimaYAML, filePath string, warn bool) {
 	instDir := filepath.Dir(filePath)
 
 	// existingLimaVersion can be empty if the instance was created with Lima prior to v0.20,
 	// or, when editing a template file without an instance (`limactl edit foo.yaml`)
 	var existingLimaVersion string
-	limaVersionFile := filepath.Join(instDir, filenames.LimaVersion)
-	if b, err := os.ReadFile(limaVersionFile); err == nil {
-		existingLimaVersion = strings.TrimSpace(string(b))
-	} else if !errors.Is(err, os.ErrNotExist) {
-		logrus.WithError(err).Warnf("Failed to read %q", limaVersionFile)
+	if warn {
+		// If warnings are enabled, then a new instance is being created using the current Lima version
+		existingLimaVersion = version.Version
+	} else {
+		limaVersionFile := filepath.Join(instDir, filenames.LimaVersion)
+		if b, err := os.ReadFile(limaVersionFile); err == nil {
+			existingLimaVersion = strings.TrimSpace(string(b))
+		} else if !errors.Is(err, os.ErrNotExist) {
+			logrus.WithError(err).Warnf("Failed to read %q", limaVersionFile)
+		}
+	}
+
+	if y.User.Username == nil {
+		y.User.Username = d.User.Username
+	}
+	if y.User.HomeDir == nil {
+		y.User.HomeDir = d.User.HomeDir
+	}
+	if y.User.UID == nil {
+		y.User.UID = d.User.UID
+	}
+	if o.User.Username != nil {
+		y.User.Username = o.User.Username
+	}
+	if o.User.HomeDir != nil {
+		y.User.HomeDir = o.User.HomeDir
+	}
+	if o.User.UID != nil {
+		y.User.UID = o.User.UID
+	}
+	if y.User.Username == nil {
+		y.User.Username = ptr.Of(osutil.LimaUser(existingLimaVersion, warn).Username)
+		warn = false
+	}
+	if y.User.HomeDir == nil {
+		y.User.HomeDir = ptr.Of(osutil.LimaUser(existingLimaVersion, warn).HomeDir)
+		warn = false
+	}
+	if y.User.UID == nil {
+		y.User.UID = ptr.Of(osutil.LimaUser(existingLimaVersion, warn).Uid)
+		// warn = false
+	}
+	if out, err := executeGuestTemplate(*y.User.HomeDir, instDir, y.User, y.Param); err == nil {
+		y.User.HomeDir = ptr.Of(out.String())
+	} else {
+		logrus.WithError(err).Warnf("Couldn't process `user.homeDir` value %q as a template", *y.User.HomeDir)
 	}
 
 	if y.VMType == nil {
@@ -406,7 +455,7 @@ func FillDefault(y, d, o *LimaYAML, filePath string) {
 		if provision.Mode == ProvisionModeDependency && provision.SkipDefaultDependencyResolution == nil {
 			provision.SkipDefaultDependencyResolution = ptr.Of(false)
 		}
-		if out, err := executeGuestTemplate(provision.Script, instDir, y.Param); err == nil {
+		if out, err := executeGuestTemplate(provision.Script, instDir, y.User, y.Param); err == nil {
 			provision.Script = out.String()
 		} else {
 			logrus.WithError(err).Warnf("Couldn't process provisioning script %q as a template", provision.Script)
@@ -477,7 +526,7 @@ func FillDefault(y, d, o *LimaYAML, filePath string) {
 		if probe.Description == "" {
 			probe.Description = fmt.Sprintf("user probe %d/%d", i+1, len(y.Probes))
 		}
-		if out, err := executeGuestTemplate(probe.Script, instDir, y.Param); err == nil {
+		if out, err := executeGuestTemplate(probe.Script, instDir, y.User, y.Param); err == nil {
 			probe.Script = out.String()
 		} else {
 			logrus.WithError(err).Warnf("Couldn't process probing script %q as a template", probe.Script)
@@ -486,13 +535,13 @@ func FillDefault(y, d, o *LimaYAML, filePath string) {
 
 	y.PortForwards = append(append(o.PortForwards, y.PortForwards...), d.PortForwards...)
 	for i := range y.PortForwards {
-		FillPortForwardDefaults(&y.PortForwards[i], instDir, y.Param)
+		FillPortForwardDefaults(&y.PortForwards[i], instDir, y.User, y.Param)
 		// After defaults processing the singular HostPort and GuestPort values should not be used again.
 	}
 
 	y.CopyToHost = append(append(o.CopyToHost, y.CopyToHost...), d.CopyToHost...)
 	for i := range y.CopyToHost {
-		FillCopyToHostDefaults(&y.CopyToHost[i], instDir, y.Param)
+		FillCopyToHostDefaults(&y.CopyToHost[i], instDir, y.User, y.Param)
 	}
 
 	if y.HostResolver.Enabled == nil {
@@ -621,7 +670,7 @@ func FillDefault(y, d, o *LimaYAML, filePath string) {
 			logrus.WithError(err).Warnf("Couldn't process mount location %q as a template", mount.Location)
 		}
 		if mount.MountPoint != nil {
-			if out, err := executeGuestTemplate(*mount.MountPoint, instDir, y.Param); err == nil {
+			if out, err := executeGuestTemplate(*mount.MountPoint, instDir, y.User, y.Param); err == nil {
 				mount.MountPoint = ptr.Of(out.String())
 			} else {
 				logrus.WithError(err).Warnf("Couldn't process mount point %q as a template", *mount.MountPoint)
@@ -811,17 +860,16 @@ func fixUpForPlainMode(y *LimaYAML) {
 	y.TimeZone = ptr.Of("")
 }
 
-func executeGuestTemplate(format, instDir string, param map[string]string) (bytes.Buffer, error) {
+func executeGuestTemplate(format, instDir string, user User, param map[string]string) (bytes.Buffer, error) {
 	tmpl, err := template.New("").Parse(format)
 	if err == nil {
-		user, _ := osutil.LimaUser(false)
 		name := filepath.Base(instDir)
 		data := map[string]interface{}{
-			"Home":     fmt.Sprintf("/home/%s.linux", user.Username),
 			"Name":     name,
 			"Hostname": identifierutil.HostnameFromInstName(name), // TODO: support customization
-			"UID":      user.Uid,
-			"User":     user.Username,
+			"UID":      *user.UID,
+			"User":     *user.Username,
+			"Home":     *user.HomeDir,
 			"Param":    param,
 		}
 		var out bytes.Buffer
@@ -835,16 +883,14 @@ func executeGuestTemplate(format, instDir string, param map[string]string) (byte
 func executeHostTemplate(format, instDir string, param map[string]string) (bytes.Buffer, error) {
 	tmpl, err := template.New("").Parse(format)
 	if err == nil {
-		user, _ := osutil.LimaUser(false)
-		home, _ := os.UserHomeDir()
 		limaHome, _ := dirnames.LimaDir()
 		data := map[string]interface{}{
 			"Dir":  instDir,
-			"Home": home,
 			"Name": filepath.Base(instDir),
 			// TODO: add hostname fields for the host and the guest
-			"UID":   user.Uid,
-			"User":  user.Username,
+			"UID":   currentUser.Uid,
+			"User":  currentUser.Username,
+			"Home":  userHomeDir,
 			"Param": param,
 
 			"Instance": filepath.Base(instDir), // DEPRECATED, use `{{.Name}}`
@@ -858,7 +904,7 @@ func executeHostTemplate(format, instDir string, param map[string]string) (bytes
 	return bytes.Buffer{}, err
 }
 
-func FillPortForwardDefaults(rule *PortForward, instDir string, param map[string]string) {
+func FillPortForwardDefaults(rule *PortForward, instDir string, user User, param map[string]string) {
 	if rule.Proto == "" {
 		rule.Proto = ProtoTCP
 	}
@@ -890,7 +936,7 @@ func FillPortForwardDefaults(rule *PortForward, instDir string, param map[string
 		}
 	}
 	if rule.GuestSocket != "" {
-		if out, err := executeGuestTemplate(rule.GuestSocket, instDir, param); err == nil {
+		if out, err := executeGuestTemplate(rule.GuestSocket, instDir, user, param); err == nil {
 			rule.GuestSocket = out.String()
 		} else {
 			logrus.WithError(err).Warnf("Couldn't process guestSocket %q as a template", rule.GuestSocket)
@@ -908,9 +954,9 @@ func FillPortForwardDefaults(rule *PortForward, instDir string, param map[string
 	}
 }
 
-func FillCopyToHostDefaults(rule *CopyToHost, instDir string, param map[string]string) {
+func FillCopyToHostDefaults(rule *CopyToHost, instDir string, user User, param map[string]string) {
 	if rule.GuestFile != "" {
-		if out, err := executeGuestTemplate(rule.GuestFile, instDir, param); err == nil {
+		if out, err := executeGuestTemplate(rule.GuestFile, instDir, user, param); err == nil {
 			rule.GuestFile = out.String()
 		} else {
 			logrus.WithError(err).Warnf("Couldn't process guest %q as a template", rule.GuestFile)