Caching of HTML + CSS problematic

[joshbruce]

Describe the bug

• HTML documents are cached for 2 days - updating too often right now for that to make sense.
• CSS is cached for 30 days - updating too often for that to make sense.

Custom cache setting aren't overriding previously set values; the favicon.ico has two cache-control values.

It seems the cache-busting recommendation of today is the same as it was ca. 2001 (Flash); append link URL with a query string that gets updated when the style sheet gets updated.

Proposed solution

• Modify .htaccess temporarily (60 days??) to be no-cache - the following are targets and should be incrementally increased to achieve as things stabilize:
  • assets/favicons 30 days
  • assets/css 7 days (w/ query string)
  • assets/js 7 days (w/ query string)
  • media/* 30 days
  • text/html 2 days
• Use git log on CSS and JS files to append file url query string: git log -n 1 --pretty=format:%H -- my/file.c
  • Using microtome for now

Resources and references

• https://www.askapache.com/htaccess/using-filesmatch-and-files-in-htaccess/
• https://robinroelofsen.com/browser-caching-htaccess-apache
• https://httpd.apache.org/docs/2.2/mod/mod_expires.html
  • ExpiresByType image/gif "modification plus 5 hours 3 minutes": Note that if you use a modification date based setting, the Expires header will not be added to content that does not come from a file on disk. This is due to the fact that there is no modification time for such content.