ADHOC: s3 bucket name verification (#4189)

* ADHOC: s3 bucket name verification

* add test

weed/shell/command_s3_bucket_create.go

@@ -5,8 +5,11 @@ import (
 	"flag"
 	"fmt"
 	"io"
+	"net"
 	"os"
+	"strings"
 	"time"
+	"unicode"
 
 	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
 )
@@ -42,6 +45,11 @@ func (c *commandS3BucketCreate) Do(args []string, commandEnv *CommandEnv, writer
 		return fmt.Errorf("empty bucket name")
 	}
 
+	err = verifyS3BucketName(*bucketName)
+	if err != nil {
+		return err
+	}
+
 	err = commandEnv.WithFilerClient(false, func(client filer_pb.SeaweedFilerClient) error {
 
 		resp, err := client.GetFilerConfiguration(context.Background(), &filer_pb.GetFilerConfigurationRequest{})
@@ -78,3 +86,35 @@ func (c *commandS3BucketCreate) Do(args []string, commandEnv *CommandEnv, writer
 	return err
 
 }
+
+// https://docs.aws.amazon.com/AmazonS3/latest/userguide/bucketnamingrules.html
+func verifyS3BucketName(name string) (err error) {
+	if len(name) < 3 || len(name) > 63 {
+		return fmt.Errorf("bucket name must between [3, 63] characters")
+	}
+	for idx, ch := range name {
+		if !(unicode.IsLower(ch) || ch == '.' || ch == '-' || unicode.IsNumber(ch)) {
+			return fmt.Errorf("bucket name can only contain lower case characters, numbers, dots, and hyphens")
+		}
+		if idx > 0 && (ch == '.' && name[idx-1] == '.') {
+			return fmt.Errorf("bucket names must not contain two adjacent periods")
+		}
+		//TODO buckets with s3 transfer accleration cannot have . in name
+	}
+	if name[0] == '.' || name[0] == '-' {
+		return fmt.Errorf("name must start with number or lower case character")
+	}
+	if name[len(name)-1] == '.' || name[len(name)-1] == '-' {
+		return fmt.Errorf("name must end with number or lower case character")
+	}
+	if strings.HasPrefix(name, "xn--") {
+		return fmt.Errorf("prefix xn-- is a reserved and not allowed in bucket prefix")
+	}
+	if strings.HasSuffix(name, "-s3alias") {
+		return fmt.Errorf("suffix -s3alias is a reserved and not allowed in bucket suffix")
+	}
+	if net.ParseIP(name) != nil {
+		return fmt.Errorf("bucket name cannot be ip addresses")
+	}
+	return nil
+}