count space taken on disk

Author: ashald

driver/driver.go

@@ -215,7 +215,8 @@ func (d Driver) Get(req *v.GetRequest) (*v.GetResponse, error) {
 		CreatedAt:  fmt.Sprintf(vol.CreatedAt.Format(time.RFC3339)),
 		Mountpoint: vol.MountPointPath,
 		Status: map[string]interface{}{
-			"size": strconv.FormatUint(vol.SizeInBytes, 10),
+			"size-max": 	strconv.FormatUint(vol.MaxSizeInBytes, 10),
+			"size-current": strconv.FormatUint(vol.CurrentSizeInBytes, 10),
 		},
 	}
 

main.go

@@ -16,21 +16,21 @@ const (
 )
 
 type config struct {
-	StateDir			string `arg:"--state-dir,env:STATE_DIR,help:dir used to keep track of currently mounted volumes"`
-	DataDir				string `arg:"--data-dir,env:DATA_DIR,help:dir used to store actual volume data"`
-	MountDir			string `arg:"--mount-dir,env:MOUNT_DIR,help:dir used to create mount-points"`
-	DefaultSize			string `arg:"--default-size,env:DEFAULT_SIZE,help:default size for volumes created"`
-	Debug         		bool   `arg:"env:DEBUG,help:enable debug logs"`
+	StateDir    string `arg:"--state-dir,env:STATE_DIR,help:dir used to keep track of currently mounted volumes"`
+	DataDir     string `arg:"--data-dir,env:DATA_DIR,help:dir used to store actual volume data"`
+	MountDir    string `arg:"--mount-dir,env:MOUNT_DIR,help:dir used to create mount-points"`
+	DefaultSize string `arg:"--default-size,env:DEFAULT_SIZE,help:default size for volumes created"`
+	Debug       bool   `arg:"env:DEBUG,help:enable debug logs"`
 }
 
 var (
-	logger         = zerolog.New(os.Stdout)
-	args           = &config{
-		StateDir: "/run/docker-volume-loopback",
-		DataDir: "/var/lib/docker-volume-loopback",
-		MountDir: "/mnt",
+	logger = zerolog.New(os.Stdout)
+	args   = &config{
+		StateDir:    "/run/docker-volume-loopback",
+		DataDir:     "/var/lib/docker-volume-loopback",
+		MountDir:    "/mnt",
 		DefaultSize: "1G",
-		Debug:	false,
+		Debug:       false,
 	}
 )
 
@@ -47,10 +47,10 @@ func main() {
 	}
 
 	d, err := driver.NewDriver(driver.Config{
-		StateDir:			args.StateDir,
-		DataDir:			args.DataDir,
-		MountDir:			args.MountDir,
-		DefaultSize:    	args.DefaultSize,
+		StateDir:    args.StateDir,
+		DataDir:     args.DataDir,
+		MountDir:    args.MountDir,
+		DefaultSize: args.DefaultSize,
 	})
 	if err != nil {
 		logger.Fatal().

manager/manager.go

@@ -14,22 +14,21 @@ import (
 
 var (
 	NamePattern = `^[a-zA-Z0-9][\w\-]{1,250}$`
-	NameRegex = regexp.MustCompile(NamePattern)
+	NameRegex   = regexp.MustCompile(NamePattern)
 )
 
 type Manager struct {
-	stateDir	string
-	dataDir     string
-	mountDir	string
+	stateDir string
+	dataDir  string
+	mountDir string
 }
 
 type Config struct {
-	StateDir	string
-	DataDir		string
-	MountDir	string
+	StateDir string
+	DataDir  string
+	MountDir string
 }
 
-
 func (m Manager) getVolume(name string) (vol Volume, err error) {
 	volumeDataFilePath := filepath.Join(m.dataDir, name)
 
@@ -49,20 +48,28 @@ func (m Manager) getVolume(name string) (vol Volume, err error) {
 		return
 	}
 
+	details, ok := volumeDataFileInfo.Sys().(*syscall.Stat_t)
+	if !ok {
+		err = errors.Errorf(
+			"An issue occurred while retrieving details about volume '%s' - cannot stat '%s'",
+			name, volumeDataFilePath)
+	}
+
 	mountPointPath := filepath.Join(m.mountDir, name)
 
 	vol = Volume{
-		Name:           name,
-		SizeInBytes:    uint64(volumeDataFileInfo.Size()),
-		StateDir:       filepath.Join(m.stateDir, name),
-		DataFilePath:   volumeDataFilePath,
-		MountPointPath: mountPointPath,
-		CreatedAt:      volumeDataFileInfo.ModTime(),
+		Name:               name,
+		CurrentSizeInBytes: uint64(details.Blocks * 512),
+		MaxSizeInBytes:     uint64(details.Size),
+		StateDir:           filepath.Join(m.stateDir, name),
+		DataFilePath:       volumeDataFilePath,
+		MountPointPath:     mountPointPath,
+		CreatedAt:          volumeDataFileInfo.ModTime(),
 	}
+
 	return
 }
 
-
 func New(cfg Config) (manager Manager, err error) {
 	// state dir
 	if cfg.StateDir == "" {
@@ -131,7 +138,6 @@ func (m Manager) List() ([]Volume, error) {
 	return vols, nil
 }
 
-
 func (m Manager) Get(name string) (vol Volume, err error) {
 	err = validateName(name)
 	if err != nil {
@@ -145,7 +151,6 @@ func (m Manager) Get(name string) (vol Volume, err error) {
 	return
 }
 
-
 func (m Manager) Create(name string, sizeInBytes int64, sparse bool, uid, gid int, mode uint32) error {
 	err := validateName(name)
 	if err != nil {
@@ -179,7 +184,9 @@ func (m Manager) Create(name string, sizeInBytes int64, sparse bool, uid, gid in
 			name, dataFilePath)
 	}
 
+	fmt.Println(fmt.Sprintf("--- %v", sparse))
 	if sparse {
+		fmt.Println(fmt.Sprintf("--- Creating as sparse"))
 		err = dataFileInfo.Truncate(sizeInBytes)
 		if err != nil {
 			_ = os.Remove(dataFilePath) // attempt to cleanup
@@ -188,11 +195,13 @@ func (m Manager) Create(name string, sizeInBytes int64, sparse bool, uid, gid in
 				name, sizeInBytes)
 		}
 	} else {
+		fmt.Println(fmt.Sprintf("--- Creating as fallocate"))
 		// Try using fallocate - super fast if data dir is on ext4 or xfs
 		errBytes, err := exec.Command("fallocate", "-l", fmt.Sprint(sizeInBytes), dataFilePath).CombinedOutput()
 
 		// fallocate failed - either not enough space or unsupported FS
 		if err != nil {
+			fmt.Println(fmt.Sprintf("--- fallocate failed"))
 			errStr := strings.TrimSpace(string(errBytes[:]))
 
 			// If there is not enough space then we just error out
@@ -209,7 +218,7 @@ func (m Manager) Create(name string, sizeInBytes int64, sparse bool, uid, gid in
 			errBytes, err = exec.Command(
 				"dd",
 				"if=/dev/zero", of, fmt.Sprintf("bs=%d", bs), fmt.Sprintf("count=%d", count),
-				).CombinedOutput()
+			).CombinedOutput()
 
 			// Something went wrong - likely no space on an fallocate-incompatible FS
 			if err != nil {
@@ -445,4 +454,4 @@ func validateName(name string) error {
 			name, NamePattern)
 	}
 	return nil
-}
+}

manager/volume.go

@@ -8,13 +8,13 @@ import (
 )
 
 type Volume struct {
-	Name           string
-	SizeInBytes    uint64
-	StateDir       string
-	DataFilePath   string
-	MountPointPath string
-	CreatedAt      time.Time
-
+	Name               string
+	CurrentSizeInBytes uint64
+	MaxSizeInBytes     uint64
+	StateDir           string
+	DataFilePath       string
+	MountPointPath     string
+	CreatedAt          time.Time
 }
 
 func (v Volume) IsMounted() (mounted bool, err error) {