private String configIdUrlPart(boolean rec, String configId) {
            if ("".equals(configId)) return "";
            if (rec) return "/" + configId;
            return "/" + configId + "/";
        }
The listing URL for this config in this service

@param key config key
@param rec recursive
@return url
configserver/src/main/java/com/yahoo/vespa/config/server/http/v2/HttpListConfigsHandler.java