Changes to support xpra

fs/fs.go

@@ -20,9 +20,11 @@ type directory struct {
 
 type Filesystem struct {
 	log *logging.Logger
-	home         string
+	user         *user.User
+	name		 string
 	base         string
 	root         string
+	xpra 		 string
 	userID       string
 	noDefaults   bool
 	noSysAndProc bool
@@ -34,6 +36,10 @@ func (fs *Filesystem) Root() string {
 	return fs.root
 }
 
+func (fs *Filesystem) Xpra() string {
+	return fs.xpra
+}
+
 func (fs *Filesystem) addWhitelist(path, target string, readonly bool) error {
 	item, err := fs.newItem(path, target, readonly)
 	if err != nil {
@@ -65,8 +71,8 @@ func (fs *Filesystem) newItem(path, target string, readonly bool) (*mountItem, e
 	}, nil
 }
 
-func NewFromProfile(profile *oz.Profile, log *logging.Logger) *Filesystem {
-	fs := NewFilesystem(profile.Name, log)
+func NewFromProfile(profile *oz.Profile, user *user.User, log *logging.Logger) *Filesystem {
+	fs := NewFilesystem(profile.Name, user, log)
 	for _,wl := range profile.Whitelist {
 		fs.addWhitelist(wl.Path, wl.Path, wl.ReadOnly)
 	}
@@ -75,24 +81,22 @@ func NewFromProfile(profile *oz.Profile, log *logging.Logger) *Filesystem {
 	}
 	fs.noDefaults = profile.NoDefaults
 	fs.noSysAndProc = profile.NoSysProc
+	if profile.XServer.Enabled {
+		fs.xpra = path.Join(user.HomeDir, ".Xoz", profile.Name)
+	}
 	return fs
 }
 
-func NewFilesystem(name string, log *logging.Logger) *Filesystem {
-
+func NewFilesystem(name string, user *user.User, log *logging.Logger) *Filesystem {
 	fs := new(Filesystem)
 	fs.log = log
+	fs.name = name
 	if log == nil {
 		fs.log = logging.MustGetLogger("oz")
 	}
 	fs.base = path.Join("/srv/oz", name)
 	fs.root = path.Join(fs.base, "rootfs")
-
-	u, err := user.Current()
-	if err != nil {
-		panic("Failed to look up current user: " + err.Error())
-	}
-	fs.home = u.HomeDir
+	fs.user = user
 	fs.userID = strconv.Itoa(os.Getuid())
 
 	return fs
@@ -205,3 +209,17 @@ func copyFileInfo(info os.FileInfo, target string) error {
 	os.Chmod(target, info.Mode().Perm())
 	return nil
 }
+
+func createSubdirs(base string, uid,gid int, mode os.FileMode, subdirs ...string) error {
+	dir := base
+	for _,sd := range subdirs {
+		dir = path.Join(dir, sd)
+		if err := os.Mkdir(dir, mode); err != nil && !os.IsExist(err) {
+			return err
+		}
+		if err := os.Chown(dir, uid, gid); err != nil {
+			return err
+		}
+	}
+	return nil
+}

fs/item.go

@@ -80,8 +80,9 @@ func (mi *mountItem) readSourceInfo(src string) (os.FileInfo, error) {
 		return nil, fmt.Errorf("source path (%s) does not exist", src)
 	}
 
-	if !strings.HasPrefix(src, mi.fs.home) {
-		return nil, fmt.Errorf("mount item (%s) has flag MountCreateIfAbsent, but is not child of home directory (%s)", src, mi.fs.home)
+	home := mi.fs.user.HomeDir
+	if !strings.HasPrefix(src, home) {
+		return nil, fmt.Errorf("mount item (%s) has flag MountCreateIfAbsent, but is not child of home directory (%s)", src, home)
 	}
 
 	if err := os.MkdirAll(src, 0750); err != nil {

fs/resolve.go

@@ -30,7 +30,7 @@ func (fs *Filesystem) resolveVars(p string) (string, error) {
 		return resolved, nil
 
 	case strings.HasPrefix(p, homeVar):
-		return path.Join(fs.home, p[len(homeVar):]), nil
+		return path.Join(fs.user.HomeDir, p[len(homeVar):]), nil
 
 	case strings.HasPrefix(p, uidVar):
 		return strings.Replace(p, uidVar, fs.userID, -1), nil

fs/setup.go

@@ -5,6 +5,9 @@ import (
 	"os"
 	"path"
 	"syscall"
+	"os/user"
+	"strconv"
+	"errors"
 )
 
 var basicBindDirs = []string{
@@ -37,6 +40,16 @@ var basicSymlinks = [][2]string{
 }
 
 func (fs *Filesystem) Setup() error {
+	if fs.xpra != "" {
+		if err := fs.createXpraDir(); err != nil {
+			return err
+		}
+		item,err := fs.newItem(fs.xpra, fs.xpra, false)
+		if err != nil {
+			return err
+		}
+		fs.whitelist = append(fs.whitelist, item)
+	}
 	if err := fs.setupRootfs(); err != nil {
 		return err
 	}
@@ -46,6 +59,30 @@ func (fs *Filesystem) Setup() error {
 	return fs.setupMountItems()
 }
 
+func (fs *Filesystem) createXpraDir() error {
+	uid,gid,err := userIds(fs.user)
+	if err != nil {
+		return err
+	}
+	dir := path.Join(fs.user.HomeDir, ".Xoz", fs.name)
+	if err := createSubdirs(fs.user.HomeDir, uid, gid, 0755, ".Xoz", fs.name); err != nil {
+		return fmt.Errorf("failed to create xpra directory (%s): %v", dir, err)
+	}
+	return nil
+}
+
+func userIds(user *user.User) (int, int, error) {
+	uid,err := strconv.Atoi(user.Uid)
+	if err != nil {
+		return -1,-1, errors.New("failed to parse uid from user struct: "+ err.Error())
+	}
+	gid,err := strconv.Atoi(user.Gid)
+	if err != nil {
+		return -1,-1, errors.New("failed to parse gid from user struct: "+ err.Error())
+	}
+	return uid,gid,nil
+}
+
 func (fs *Filesystem) setupRootfs() error {
 	if err := os.MkdirAll(fs.base, 0755); err != nil {
 		return fmt.Errorf("unable to create directory (%s): %v", fs.base, err)