Procedure

1. Use the add_header command to specify a custom HTTP header:

   add_header name value;

   For example, you can run the following command to create a header Cache-Control to specify that the resource is not cached:

   add_header Cache-Control "no-cache";

2. Run the following expires command to configure the time-to-live (TTL):

   expires [time|epoch|max|off];

   • off : does not allow modifying the Expires or Cache-Control response header.

   • time : specifies the time when the cache expires. For example, expires 1h; indicates that the cache expires in 1 hour.

   • epoch : sets the Expires header to a timestamp that follows the UNIX time format. It is the number of seconds that have elapsed since 00:00:00 Thursday, January 1, 1970.

   • max : sets the Expires header to a future point in time and the Cache-Control header to 10 years.

Sample configurations

• Set the TTL of PHP files to 1 hour.

  location ~ \.php$ {
   expires 1h;
  }

• Set the cache policy for PHP files to no-cache.

  location ~ \.php$ {
   add_header Cache-Control "no-cache";
  }

This way, you can configure different cache policies for different types of resources or specific locations based on your business requirements.