Razvan Stanga

Complete WordPress Varnish Cache 3.x/4.x/5.x and Nginx Proxy Cache integration.
This plugin handles all integration with Varnish Cache and Nginx Proxy Cache. It was designed for high traffic websites.
Main features
<ul>
<li>admin interface, see screenshots</li>
<li>console for manual purges, supports regular expressions so you can purge an entire folder or just a single file</li>
<li>supports every type of Varnish Cache implementation, see screenshots for examples</li>
<li>unlimited number of Varnish Cache servers</li>
<li>use of custom headers when communicating with Varnish Cache does not interfere with other caching plugins, cloudflare, etc</li>
<li>Varnish Cache configuration generator</li>
<li>purge key method so you don’t need to setup ACLs</li>
<li>debugging</li>
<li>actively maintained</li>
</ul>
You can control the following from the Varnish Caching admin panel :
<ul>
<li>Enable/Disable caching</li>
<li>Homepage cache TTL</li>
<li>Cache TTL (for every other page)</li>
<li>IPs/Hosts to clear cache to support every type of Varnish Cache implementation</li>
<li>Override default TTL in posts/pages</li>
<li>Purge key based PURGE</li>
<li>Logged in cookie</li>
<li>Debugging option</li>
<li>console for precise manual purges</li>
</ul>
This plugin also auto purges Varnish Cache / Nginx Proxy Cache when your site is modified.
Varnish Caching sends a PURGE request to Varnish Cache / Nginx Proxy Cache when a page or post is modified. This occurs when editing, publishing, commenting or deleting an item, and when changing themes. 
Not all pages are purged every time, depending on your Varnish / Nginx Proxy Cache configuration. When a post, page, or custom post type is edited, or a new comment is added, only the following pages will purge:
<ul>
<li>The front page</li>
<li>The post/page edited</li>
<li>Any categories or tags associated with the page</li>
</ul>
<a href="https://www.varnish-cache.org/" rel="nofollow ugc">Varnish Cache</a> / <a href="https://www.nginx.com/blog/nginx-caching-guide/" rel="nofollow ugc">Nginx Proxy Cache</a> is a web application accelerator also known as a caching HTTP reverse proxy. You install it in front of any server that speaks HTTP and configure it to cache the contents. This plugin does not install Varnish/Nginx for you, nor does it configure Varnish/Nginx for WordPress. It’s expected you already did that on your own using the provided config files.
Inspired from the following :
<ul>
<li>https://wordpress.org/plugins/varnish-http-purge/</li>
<li>https://github.com/dreamhost/varnish-vcl-collection/</li>
</ul>

Varnish/Nginx Proxy Caching

Wordpress Varnish Cache 3.x/4.x/5.x and Nginx Proxy Cache integration

Viktor Szépe

“It’s important to make resources (images, scripts, stylesheets, etc.) cacheable.”
<a href="http://www.stevesouders.com/blog/2008/08/23/revving-filenames-dont-use-querystring/" rel="nofollow ugc">Steve Souders</a>
It is much easier to use a CDN without Query String Parameters. 
This plugins alters only local resources’ URL-s. 
The <code>ver</code> Query String Parameter will be inserted into the filename.
For example <code>jquery.min.js?ver=1.10</code> becomes <code>jquery.min.110.js</code>.
To reverse this in the web server add this line to your nginx config:
<pre><code>server {
 location ~ ^(.+)\.\d\d+\.(js|css|png|jpg|jpeg|gif|ico)$ {
 #try_files $uri $1.$2 /index.php?$args;
 try_files $uri $1.$2 =404;
 }
}
</code></pre>
Or to your Apache configuration or <code>.htaccess</code> file.
<pre><code>RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.+)\.\d\d+\.(js|css|png|jpg|jpeg|gif|ico)$ $1.$2 [NC,L]
</code></pre>
<h4>Testing the plugin before live usage</h4>
You can test the plugin by replacing the two <code>add_filter()</code> calls with this
<pre><code>require_once( dirname( dirname( dirname( dirname( __FILE__ ) ) ) ) . '/wp-load.php' );
wp();
echo o1_revving_src( $argv[1] ) . PHP_EOL;
</code></pre>
Then start it from CLI: <code>php revving.php <TEST-URL></code>
<h4>Links</h4>
Development of this plugin goes on on <a href="https://github.com/szepeviktor/resource-versioning" rel="nofollow ugc">GitHub</a>.

Resource Versioning

Turn Query String Parameters into file revision numbers.

Varnish/Nginx Proxy Caching vs Resource Versioning