By default, all files will have a cache lifetime of only 7 days because that's what's set in the .htaccess file. It would be great if we could specify a longer lifetime for static assets.

Here is the recommended code from AdvAgg for Drupal:

<FilesMatch "^(css|js)__[A-Za-z0-9-_]{43}__[A-Za-z0-9-_]{43}__[A-Za-z0-9-_]{43}.(css|js)(\.gz|\.br)?">
  # No mod_headers. Apache module headers is not enabled.
  <IfModule !mod_headers.c>
    # No mod_expires. Apache module expires is not enabled.
    <IfModule !mod_expires.c>
      # Use ETags.
      FileETag MTime Size
    </IfModule>
  </IfModule>

  # Use Expires Directive if apache module expires is enabled.
  <IfModule mod_expires.c>
    # Do not use ETags.
    FileETag None
    # Enable expirations.
    ExpiresActive On
    # Cache all aggregated css/js files for 52 weeks after access (A).
    ExpiresDefault A31449600
  </IfModule>

  # Use Headers Directive if apache module headers is enabled.
  <IfModule mod_headers.c>
    # Do not use etags for cache validation.
    Header unset ETag
    <IfModule !mod_expires.c>
      # Set a far future Cache-Control header to 52 weeks.
      Header set Cache-Control "max-age=31449600, no-transform, public"
    </IfModule>
    <IfModule mod_expires.c>
      Header append Cache-Control "no-transform, public"
    </IfModule>
  </IfModule>
</FilesMatch>
GitHub Issue #: 
3937