Add enable flag for LDAP IDP config (#16805)

cmd/admin-handlers-idp-config.go

@@ -86,7 +86,7 @@ func (a adminAPIHandlers) addOrUpdateIDPHandler(ctx context.Context, w http.Resp
 		if idpCfgType == madmin.LDAPIDPCfg && cfgName != madmin.Default {
 			// LDAP does not support multiple configurations. So cfgName must be
 			// empty or `madmin.Default`.
-			writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrBadRequest), r.URL)
+			writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrAdminConfigLDAPNonDefaultConfigName), r.URL)
 			return
 		}
 	}

cmd/api-errors.go

@@ -281,6 +281,7 @@ const (
 	ErrAdminConfigEnvOverridden
 	ErrAdminConfigDuplicateKeys
 	ErrAdminConfigInvalidIDPType
+	ErrAdminConfigLDAPNonDefaultConfigName
 	ErrAdminConfigLDAPValidation
 	ErrAdminConfigIDPCfgNameAlreadyExists
 	ErrAdminConfigIDPCfgNameDoesNotExist
@@ -1333,6 +1334,11 @@ var errorCodes = errorCodeMap{
 		Description:    fmt.Sprintf("Invalid IDP configuration type - must be one of %v", madmin.ValidIDPConfigTypes),
 		HTTPStatusCode: http.StatusBadRequest,
 	},
+	ErrAdminConfigLDAPNonDefaultConfigName: {
+		Code:           "XMinioAdminConfigLDAPNonDefaultConfigName",
+		Description:    "Only a single LDAP configuration is supported - config name must be empty or `_`",
+		HTTPStatusCode: http.StatusBadRequest,
+	},
 	ErrAdminConfigLDAPValidation: {
 		Code:           "XMinioAdminConfigLDAPValidation",
 		Description:    "LDAP Configuration validation failed",