Cache expiration header in additional Nginx directives does not get applied

Symptoms

• Cache expiration is enabled in Nginx in Plesk according to the article with expiration time set explicitly, but cache expiration headers are not returned:

  # wget -S https://example.com/wp-content/uploads/file.jpg 2>&1 | egrep “Server|Content-Type|Cache-Control|Expires”
  Server: nginx
  Content-Type: image/jpeg

• Website is a WordPress instance.

• In Domains > example.com > PHP Settings for a domain PHP handler is set as FPM application served by nginx.

Cause

This is Plesk internal issue with ID #PPPM-4413, which is planned to be fixed in future Plesk updates.

Resolution

As a workaround, apply the following solution:

1. Log into Plesk.

2. Change PHP handler to FPM application served by Apache in Domains > example.com > PHP Settings.

3. Check if Leveraging Browser Caching for nginx is enabled, for example:

   # wget -S https://example.com/wp-content/uploads/file.jpg 2>&1 | egrep “Server|Content-Type|Cache-Control|Expires”
   Server: nginx
   Content-Type: image/jpeg
   Expires: Thu, 05 Oct 2017 20:36:13 GMT
   Cache-Control: max-age=604800

   # curl -I -c – “https://example.com/wp-content/uploads/file.jpg” -k
   …
   Expires: Thu, 05 Oct 2017 20:53:53 GMT
   Cache-Control: max-age=604800
   …