disallow bucket replication setup with site replication (#17189)

cmd/admin-bucket-handlers.go

@@ -210,6 +210,11 @@ func (a adminAPIHandlers) SetRemoteTargetHandler(w http.ResponseWriter, r *http.
 		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErrWithErr(ErrAdminConfigBadJSON, err), r.URL)
 		return
 	}
+	if globalSiteReplicationSys.isEnabled() && !update {
+		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErrWithErr(ErrRemoteTargetDenyAddError, err), r.URL)
+		return
+	}
+
 	if update {
 		// overlay the updates on existing target
 		tgt := globalBucketTargetSys.GetRemoteBucketTargetByArn(ctx, bucket, target.Arn)
@@ -220,14 +225,14 @@ func (a adminAPIHandlers) SetRemoteTargetHandler(w http.ResponseWriter, r *http.
 		for _, op := range ops {
 			switch op {
 			case madmin.CredentialsUpdateType:
-				if globalSiteReplicationSys.isEnabled() {
+				if !globalSiteReplicationSys.isEnabled() {
-					writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErrWithErr(ErrRemoteTargetDenyEditError, err), r.URL)
+					// credentials update is possible only in bucket replication. User will never
-					return
+					// know the site replicator creds.
-				}
 					tgt.Credentials = target.Credentials
 					tgt.TargetBucket = target.TargetBucket
 					tgt.Secure = target.Secure
 					tgt.Endpoint = target.Endpoint
+				}
 			case madmin.SyncUpdateType:
 				tgt.ReplicationSync = target.ReplicationSync
 			case madmin.ProxyUpdateType:

cmd/api-errors.go

@@ -135,7 +135,7 @@ const (
 	ErrReplicationNeedsVersioningError
 	ErrReplicationBucketNeedsVersioningError
 	ErrReplicationDenyEditError
-	ErrRemoteTargetDenyEditError
+	ErrRemoteTargetDenyAddError
 	ErrReplicationNoExistingObjects
 	ErrObjectRestoreAlreadyInProgress
 	ErrNoSuchKey
@@ -934,9 +934,9 @@ var errorCodes = errorCodeMap{
 		Description:    "No matching ExistingsObjects rule enabled",
 		HTTPStatusCode: http.StatusBadRequest,
 	},
-	ErrRemoteTargetDenyEditError: {
+	ErrRemoteTargetDenyAddError: {
-		Code:           "XMinioAdminRemoteTargetDenyEdit",
+		Code:           "XMinioAdminRemoteTargetDenyAdd",
-		Description:    "Cannot alter remote target endpoint since this server is in a cluster replication setup. use `mc admin replicate update`",
+		Description:    "Cannot add remote target endpoint since this server is in a cluster replication setup",
 		HTTPStatusCode: http.StatusBadRequest,
 	},
 	ErrReplicationDenyEditError: {