Purge Varnish Cache when post content on your site is modified.
I was testing this plugin in depth last days over many Varnish installations (Ubuntu, CentOS and Debian). The plugin do a good job, is easy to install and easy to configure.
I had to edit the
wp-config.php file in all my WordPress installations because the plugin by default use external IP or Public IP to perform PURGE requests. Then you have two options, modify
wp-config.php or modifify Varnish VCL file. At our hosting company we decided to modify
wp-config.php file becaue we consider that allow external PURGE requests is a bad security practice.
The plugin advantage is its simplicity, there is no configuration needed. But this simplicity adds the bad point of the plugin, it not offers to configure wich pages purge after edit or post a new blog post.
I rate it with three starts because from my point of view use external purge requests is not secure.
We wrote a guide (in spanish) about how to purge cache from varnish using wordpress and this plugin or W3 Total cache, you can read this one here here