a2enmod expires
service apache2 restart
vim /etc/apache2/sites-available/site.conf
<IfModule mod_expires.c>
<FilesMatch "\.(jpe?g|png|gif|js|css)$">
ExpiresActive On
ExpiresDefault "access plus 1 year"
</FilesMatch>
</IfModule>
a2enmod expires
service apache2 restart
vim /etc/apache2/sites-available/site.conf
<IfModule mod_expires.c>
<FilesMatch "\.(jpe?g|png|gif|js|css)$">
ExpiresActive On
ExpiresDefault "access plus 1 year"
</FilesMatch>
</IfModule>