s3: skip permission checking for creating bucket if the bucket already exists

fix https://github.com/chrislusf/seaweedfs/issues/2417

Rclone was trying to create the bucket even though the bucket already exists.

weed/s3api/s3api_bucket_handlers.go

@@ -111,6 +111,11 @@ func (s3a *S3ApiServer) PutBucketHandler(w http.ResponseWriter, r *http.Request)
 		return
 	}
 
+	if _, errCode = s3a.iam.authRequest(r, s3_constants.ACTION_ADMIN); errCode != s3err.ErrNone {
+		s3err.WriteErrorResponse(w, r, errCode)
+		return
+	}
+
 	fn := func(entry *filer_pb.Entry) {
 		if identityId := r.Header.Get(xhttp.AmzIdentityId); identityId != "" {
 			if entry.Extended == nil {

weed/s3api/s3api_server.go

@@ -137,7 +137,7 @@ func (s3a *S3ApiServer) registerRouter(router *mux.Router) {
 		bucket.Methods("GET").HandlerFunc(track(s3a.iam.Auth(s3a.ListObjectsV1Handler, ACTION_LIST), "LIST"))
 
 		// PutBucket
-		bucket.Methods("PUT").HandlerFunc(track(s3a.iam.Auth(s3a.PutBucketHandler, ACTION_ADMIN), "PUT"))
+		bucket.Methods("PUT").HandlerFunc(track(s3a.PutBucketHandler, "PUT"))
 
 		// DeleteBucket
 		bucket.Methods("DELETE").HandlerFunc(track(s3a.iam.Auth(s3a.DeleteBucketHandler, ACTION_WRITE), "DELETE"))