Define functional options for DrivesBuilder

This would make
firecracker-microvm/firecracker-containerd#283
cleaner.

Signed-off-by: Kazuyoshi Kato <[email protected]>

Author: kzys

drives.go

@@ -63,3 +63,30 @@ func (b DrivesBuilder) AddDrive(path string, readOnly bool, opts ...DriveOpt) Dr
 func (b DrivesBuilder) Build() []models.Drive {
 	return append(b.drives, b.rootDrive)
 }
+
+// WithDriveID sets the ID of the drive
+func WithDriveID(id string) DriveOpt {
+	return func(d *models.Drive)  {
+		d.DriveID = String(id)
+	}
+}
+
+// WithReadOnly sets the drive read-only
+func WithReadOnly(flag bool) DriveOpt {
+	return func(d *models.Drive)  {
+		d.IsReadOnly = Bool(flag)
+	}
+}
+
+// WithPartuuid sets the unique ID of the boot partition
+func WithPartuuid(uuid string) DriveOpt {
+	return func(d *models.Drive)  {
+		d.Partuuid = uuid
+	}
+}
+// WithRateLimiter sets the rate limitter of the drive
+func WithRateLimiter(limiter models.RateLimiter) DriveOpt {
+	return func(d *models.Drive)  {
+		d.RateLimiter = &limiter
+	}
+}

drives_test.go

@@ -36,9 +36,7 @@ func TestDrivesBuilderWithRootDrive(t *testing.T) {
 	}
 
 	b := NewDrivesBuilder(expectedPath)
-	drives := b.WithRootDrive(expectedPath, func(drive *models.Drive) {
-		drive.DriveID = String("foo")
-	}).Build()
+	drives := b.WithRootDrive(expectedPath, WithDriveID("foo")).Build()
 
 	if e, a := expectedDrives, drives; !reflect.DeepEqual(e, a) {
 		t.Errorf("expected drives %v, but received %v", e, a)