Relax bucket name validation to support existing buckets. (#778)

Fixes minio/mc#2229

Author: harshavardhana

pkg/s3utils/utils.go

@@ -205,7 +205,7 @@ func EncodePath(pathName string) string {
 // We support '.' with bucket names but we fallback to using path
 // style requests instead for such buckets.
 var (
-	validBucketName       = regexp.MustCompile(`^[A-Za-z0-9][A-Za-z0-9\.\-]{1,61}[A-Za-z0-9]$`)
+	validBucketName       = regexp.MustCompile(`^[A-Za-z0-9][A-Za-z0-9\.\-\_\:]{1,61}[A-Za-z0-9]$`)
 	validBucketNameStrict = regexp.MustCompile(`^[a-z0-9][a-z0-9\.\-]{1,61}[a-z0-9]$`)
 	ipAddress             = regexp.MustCompile(`^(\d+\.){3}\d+$`)
 )
@@ -240,14 +240,13 @@ func checkBucketNameCommon(bucketName string, strict bool) (err error) {
 }
 
 // CheckValidBucketName - checks if we have a valid input bucket name.
-// This is a non stricter version.
-// - http://docs.aws.amazon.com/AmazonS3/latest/dev/UsingBucket.html
 func CheckValidBucketName(bucketName string) (err error) {
 	return checkBucketNameCommon(bucketName, false)
 }
 
 // CheckValidBucketNameStrict - checks if we have a valid input bucket name.
 // This is a stricter version.
+// - http://docs.aws.amazon.com/AmazonS3/latest/dev/UsingBucket.html
 func CheckValidBucketNameStrict(bucketName string) (err error) {
 	return checkBucketNameCommon(bucketName, true)
 }

pkg/s3utils/utils_test.go

@@ -301,10 +301,14 @@ func TestIsValidBucketName(t *testing.T) {
 		{"", errors.New("Bucket name cannot be empty"), false},
 		{"my..bucket", errors.New("Bucket name contains invalid characters"), false},
 		{"192.168.1.168", errors.New("Bucket name cannot be an ip address"), false},
+		{":bucketname", errors.New("Bucket name contains invalid characters"), false},
+		{"_bucketName", errors.New("Bucket name contains invalid characters"), false},
 		{"my.bucket.com", nil, true},
 		{"my-bucket", nil, true},
 		{"123my-bucket", nil, true},
 		{"Mybucket", nil, true},
+		{"My_bucket", nil, true},
+		{"My:bucket", nil, true},
 	}
 
 	for i, testCase := range testCases {