Upon new release, NGINX would return 200 OK with new static files.
Otherwise, NGINX would return 304 Not Modified with empty response, and browser continue to reuse cached static files.
(cherry picked from commit 4506a5e4901299dfcb8ba2524e2a6c451fffcf90)
Cache expires after 24h.
After cache is expired, browser can compare ETag to the server to check if the file has changed. If the server returns the same token, then the file is the same, and there's no need to re-download it.
(cherry picked from commit b511f2094f6961bd6d353b86cf8d0d065536d04f)
dab246