public function createSiteFolders(CNabuSite $nb_site) : bool
    {
        $vhosts_path = $this->validatePath($this->nb_server->getVirtualHostsPath());
        $vlib_path = $this->validatePath($this->nb_server->getVirtualLibrariesPath());
        $vcache_path = $this->validatePath($this->nb_server->getVirtualCachePath());

        $nb_cluster_user = $nb_site->getClusterUser();
        if ($nb_cluster_user === null) {
            throw new ENabuCoreException(ENabuCoreException::ERROR_OBJECT_EXPECTED);
        }
        $nb_cluster_user_group = $nb_cluster_user->getGroup();
        if ($nb_cluster_user_group === null) {
            throw new ENabuCoreException(ENabuCoreException::ERROR_OBJECT_EXPECTED);
        }
        $owner_name = $nb_cluster_user->getOSNick();
        $owner_group = $nb_cluster_user_group->getOSNick();

        $vhosts_path = $nb_site->getVirtualHostPath($this->nb_server);
        if (!is_dir($vhosts_path)) {
            if (!mkdir($vhosts_path, 0755, true)) {
                throw new ENabuCoreException(ENabuCoreException::ERROR_HOST_PATH_NOT_FOUND, array($vhosts_path));
            } else {
                chown($vhosts_path, $owner_name);
                chgrp($vhosts_path, $owner_group);
            }
        }
        $vlib_path = $nb_site->getVirtualLibrariesPath($this->nb_server);
        if (!is_dir($vlib_path)) {
            if (!mkdir($vlib_path, 0755, true)) {
                throw new ENabuCoreException(ENabuCoreException::ERROR_HOST_PATH_NOT_FOUND, array($vlib_path));
            } else {
                chown($vlib_path, APACHE_HTTPD_SYS_USER);
                chgrp($vlib_path, $owner_group);
            }
        }
        $vcache_path = $nb_site->getVirtualCachePath($this->nb_server);
        if (!is_dir($vcache_path)) {
            if (!mkdir($vcache_path, 0755, true)) {
                throw new ENabuCoreException(ENabuCoreException::ERROR_HOST_PATH_NOT_FOUND, array($vcache_path));
            } else {
                chown($vcache_path, APACHE_HTTPD_SYS_USER);
                chgrp($vcache_path, $owner_group);
            }
        }

        return true;
    }