opts/mount: add tmpfs-specific options

added following options:

 * tmpfs-size
 * tmpfs-mode

Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>

opts/mount.go

@@ -3,10 +3,12 @@ package opts
 import (
 	"encoding/csv"
 	"fmt"
+	"os"
 	"strconv"
 	"strings"
 
 	mounttypes "github.com/docker/docker/api/types/mount"
+	"github.com/docker/go-units"
 )
 
 // MountOpt is a Value type for parsing mounts
@@ -43,6 +45,13 @@ func (m *MountOpt) Set(value string) error {
 		return mount.BindOptions
 	}
 
+	tmpfsOptions := func() *mounttypes.TmpfsOptions {
+		if mount.TmpfsOptions == nil {
+			mount.TmpfsOptions = new(mounttypes.TmpfsOptions)
+		}
+		return mount.TmpfsOptions
+	}
+
 	setValueOnMap := func(target map[string]string, value string) {
 		parts := strings.SplitN(value, "=", 2)
 		if len(parts) == 1 {
@@ -102,6 +111,18 @@ func (m *MountOpt) Set(value string) error {
 				volumeOptions().DriverConfig.Options = make(map[string]string)
 			}
 			setValueOnMap(volumeOptions().DriverConfig.Options, value)
+		case "tmpfs-size":
+			sizeBytes, err := units.RAMInBytes(value)
+			if err != nil {
+				return fmt.Errorf("invalid value for %s: %s", key, value)
+			}
+			tmpfsOptions().SizeBytes = sizeBytes
+		case "tmpfs-mode":
+			ui64, err := strconv.ParseUint(value, 8, 32)
+			if err != nil {
+				return fmt.Errorf("invalid value for %s: %s", key, value)
+			}
+			tmpfsOptions().Mode = os.FileMode(ui64)
 		default:
 			return fmt.Errorf("unexpected key '%s' in '%s'", key, field)
 		}
@@ -115,11 +136,14 @@ func (m *MountOpt) Set(value string) error {
 		return fmt.Errorf("target is required")
 	}
 
-	if mount.Type == mounttypes.TypeBind && mount.VolumeOptions != nil {
+	if mount.VolumeOptions != nil && mount.Type != mounttypes.TypeVolume {
-		return fmt.Errorf("cannot mix 'volume-*' options with mount type '%s'", mounttypes.TypeBind)
+		return fmt.Errorf("cannot mix 'volume-*' options with mount type '%s'", mount.Type)
 	}
-	if mount.Type == mounttypes.TypeVolume && mount.BindOptions != nil {
+	if mount.BindOptions != nil && mount.Type != mounttypes.TypeBind {
-		return fmt.Errorf("cannot mix 'bind-*' options with mount type '%s'", mounttypes.TypeVolume)
+		return fmt.Errorf("cannot mix 'bind-*' options with mount type '%s'", mount.Type)
+	}
+	if mount.TmpfsOptions != nil && mount.Type != mounttypes.TypeTmpfs {
+		return fmt.Errorf("cannot mix 'tmpfs-*' options with mount type '%s'", mount.Type)
 	}
 
 	m.values = append(m.values, mount)

opts/mount_test.go

@@ -1,6 +1,7 @@
 package opts
 
 import (
+	"os"
 	"testing"
 
 	mounttypes "github.com/docker/docker/api/types/mount"
@@ -151,3 +152,33 @@ func TestMountOptTypeConflict(t *testing.T) {
 	assert.Error(t, m.Set("type=bind,target=/foo,source=/foo,volume-nocopy=true"), "cannot mix")
 	assert.Error(t, m.Set("type=volume,target=/foo,source=/foo,bind-propagation=rprivate"), "cannot mix")
 }
+
+func TestMountOptSetTmpfsNoError(t *testing.T) {
+	for _, testcase := range []string{
+		// tests several aliases that should have same result.
+		"type=tmpfs,target=/target,tmpfs-size=1m,tmpfs-mode=0700",
+		"type=tmpfs,target=/target,tmpfs-size=1MB,tmpfs-mode=700",
+	} {
+		var mount MountOpt
+
+		assert.NilError(t, mount.Set(testcase))
+
+		mounts := mount.Value()
+		assert.Equal(t, len(mounts), 1)
+		assert.DeepEqual(t, mounts[0], mounttypes.Mount{
+			Type:   mounttypes.TypeTmpfs,
+			Target: "/target",
+			TmpfsOptions: &mounttypes.TmpfsOptions{
+				SizeBytes: 1024 * 1024, // not 1000 * 1000
+				Mode:      os.FileMode(0700),
+			},
+		})
+	}
+}
+
+func TestMountOptSetTmpfsError(t *testing.T) {
+	var m MountOpt
+	assert.Error(t, m.Set("type=tmpfs,target=/foo,tmpfs-size=foo"), "invalid value for tmpfs-size")
+	assert.Error(t, m.Set("type=tmpfs,target=/foo,tmpfs-mode=foo"), "invalid value for tmpfs-mode")
+	assert.Error(t, m.Set("type=tmpfs"), "target is required")
+}