static async clearCacheES (req, res) {
    try {
      const { body: data } = await Db.clearCache(req.query.cluster);
      return res.send(JSON.stringify({
        success: true,
        text: `Cache cleared: ${data._shards.successful} of ${data._shards.total} shards successful, with ${data._shards.failed} failing`
      }));
    } catch (err) {
      console.log(`ERROR - ${req.method} /api/esadmin/clearcache`, util.inspect(err, false, 50));
      return res.serverError(500, err.toString());
    }
  }
POST - /api/esadmin/clearcache

Try and clear the cache for all indices (es admin only - set in config with <a href="settings#esadminusers">esAdminUsers</a>).
@name /esadmin/clearcache
@returns {boolean} success - Whether clearing the cache was successful.
@returns {string} text - The success/error message to (optionally) display to the user.