if the title, mainly the front-end code released to CDN, and CDN will co-exist multiple versions, according to access to information, found that there is a way is the front-end in the compilation process, will record the newly packaged file hash file name, to form a json file, if you can tell the back-end this file, the back-end can automatically splice out the html file output according to this version.json file. The question is how to tell the back end? One is how to give this file to the backend, and the other is that I store the file somewhere, and obviously there will be more than one version of this file in that place, so how do I tell the backend which file to take?