ACL driver/storage layer support

pkg/storage/drivers/driver.go

@@ -27,7 +27,7 @@ import (
 type Driver interface {
 	// Bucket Operations
 	ListBuckets() ([]BucketMetadata, error)
-	CreateBucket(bucket string) error
+	CreateBucket(bucket, acl string) error
 	GetBucketMetadata(bucket string) (BucketMetadata, error)
 
 	// Object Operations
@@ -38,10 +38,40 @@ type Driver interface {
 	CreateObject(bucket string, key string, contentType string, md5sum string, data io.Reader) error
 }
 
+// BucketACL - bucket level access control
+type BucketACL string
+
+// different types of ACL's currently supported for buckets
+const (
+	BucketPrivate         = BucketACL("private")
+	BucketPublicRead      = BucketACL("public-read")
+	BucketPublicReadWrite = BucketACL("public-read-write")
+)
+
+func (b BucketACL) String() string {
+	return string(b)
+}
+
+// IsPrivate - is acl Private
+func (b BucketACL) IsPrivate() bool {
+	return b == BucketACL("private")
+}
+
+// IsPublicRead - is acl PublicRead
+func (b BucketACL) IsPublicRead() bool {
+	return b == BucketACL("public-read")
+}
+
+// IsPublicReadWrite - is acl PublicReadWrite
+func (b BucketACL) IsPublicReadWrite() bool {
+	return b == BucketACL("public-read-write")
+}
+
 // BucketMetadata - name and create date
 type BucketMetadata struct {
 	Name    string
 	Created time.Time
+	ACL     BucketACL
 }
 
 // ObjectMetadata - object key and its relevant metadata
@@ -98,6 +128,23 @@ func GetMode(resources BucketResourcesMetadata) FilterMode {
 	return f
 }
 
+// IsValidBucketACL - is provided acl string supported
+func IsValidBucketACL(acl string) bool {
+	switch acl {
+	case "private":
+		fallthrough
+	case "public-read":
+		fallthrough
+	case "public-read-write":
+		return true
+	case "":
+		// by default its "private"
+		return true
+	default:
+		return false
+	}
+}
+
 // IsDelimiterPrefixSet Delimiter and Prefix set
 func (b BucketResourcesMetadata) IsDelimiterPrefixSet() bool {
 	return b.Mode == DelimiterPrefixMode