Flush Opcache with Varnish is here to rescue you from the constant annoyance of flushing yet another cache!
If, like me, you use PHP’s Opcache to speed up a site, and you have a Varnish cache, and maybe some other server-side caches, you probably want to flush the opcache, Varnish cache, and any other server-side caches at the same time after changing the PHP files on your server, (like, when you update WordPress, plugins, or themes). I don’t want to click a button for each cache type, or worse, have to log in to the command-line for a sudo service restart varnish after doing updates, especially if I’m doing repeated updates. Flush Opcache with Varnish hooks into Mika Epstein’s excellent Varnish HTTP Cache plugin and flushes the PHP Opcache and the WP Super Cache cache, (if you use WP Super Cache), every time you manually flush the Varnish cache, turning the Varnish HTTP Cache “Clear Cache” buttons into a three-for-one deal.
If you also use the plugin WP Opcache to manage your opcache then WP Opcache will be called to do the actual Opcache flushing so you can take advantage of its automatic rebuilding of the opcache.
I’m already using Flush Opcache with Varnish in production and it’s saving me time every time I update a theme or plugin. You can get it in the WordPress.org plugin directory.