WordPress Nginx Multisite Configuration with Nginx Microcahing

class-microcache-purge.php

/**
 * Micro Cache Purge PHP Class
 * Sends a request header to nginx to purge the microcache when post are created or updated
 * Include this file at plugins_loaded or in theme functions.php
 */	

new Micro_Cache_Purge();

class Micro_Cache_Purge {

    public function __construct() {
        add_action( 'save_post', array ( $this, 'transition_post_status' ) );
    }

    public function transition_post_status( $new, $old, $post ) {
        if ( 'publish' !== $old && 'publish' !== $new )
            return;
            $post = get_post( $post );
            $url = get_permalink( $post );

        // Purge this URL
        $this->purge( $url );

        // Purge the front page
        $this->purge( home_url( '/' ) );

        // Add any additional urls to purge eg: /blog/
        if ( 'post' === $post->post_type ) {
            $this->purge( home_url( '/blog/' ) );
         }
    }

    private function purge( $url ) {
        wp_remote_get( $url, array ( 'timeout' => 0.01, 'blocking' => false, 'headers' => array ( 'X-Nginx-Cache-Purge' => '1' ) ) );
    }
}

global-restrictions.conf

# Global restrictions configuration file.
# Designed to be included in any server {} block.

location = /favicon.ico {
	log_not_found off;
	access_log off;
}
## Comment out this block and uncomment the robots.txt block at bottom of the file to enable WordPress dynamic robots.txt

location = /robots.txt {
	allow all;
	log_not_found off;
	access_log off;
}

# Deny all attempts to access hidden files such as .htaccess, .htpasswd, .DS_Store (Mac).
location ~ /\. {
	deny all;
	access_log off;
	log_not_found off;
}

## Uncomment out this block to use WordPress dynamic robots.txt
# location = /robots.txt {
#	rewrite ^ /index.php;
# }

global-wp-multi.conf

error_page 404 = @wordpress;
log_not_found off;

location / {
	try_files $uri $uri/ /index.php?q=$uri&$args;
}

rewrite /wp-admin$ $scheme://$host$uri/ permanent;


rewrite ^/files/(.+) /wp-includes/ms-files.php?file=$1 last;

set $cachetest "$document_root/wp-content/cache/ms-filemap/${host}${uri}";
if ($uri ~ /$) {
	set $cachetest "";
}
if (-f $cachetest) {
	# Rewrites the URI and stops rewrite processing so it doesn't start over and attempt to pass it to the next rule.
	rewrite ^ /wp-content/cache/ms-filemap/${host}${uri} break;
}

location ^~ /files/ {
	rewrite ^.*/files/(.+)$ /wp-includes/ms-files.php?file=$1 last;
}

## If using W3 Total Cache include the conf file set in settings-general nginx conf file location
## Make sure WordPress can write to this file!
# include w3-total.conf;

# Rewrite multisite '.../wp-.*' and '.../*.php'.
if (!-e $request_filename) {
	rewrite ^/[_0-9a-zA-Z-]+(/wp-.*) $1 last;
	rewrite ^/[_0-9a-zA-Z-]+(/.*\.php)$ $1 last;
}

location @wordpress {
    fastcgi_pass php;
    fastcgi_param SCRIPT_FILENAME $document_root/index.php;
    include fastcgi_params;
    fastcgi_param SCRIPT_NAME /index.php;
}

location ~ \.php$ {
	fastcgi_cache microcache_fpm;
	fastcgi_cache_key $scheme$host$request_method$request_uri;
	fastcgi_cache_valid 200 304 10m;
	fastcgi_cache_use_stale updating;
	fastcgi_max_temp_file_size 1M;
	fastcgi_connect_timeout 60;
	fastcgi_send_timeout 180;
	fastcgi_read_timeout 180;
	fastcgi_buffer_size 128k;
	fastcgi_buffers 4 256k;
	fastcgi_busy_buffers_size 256k;
	fastcgi_temp_file_write_size 256k;
	set $no_cache_set  0;
	set $no_cache_get  0;

	if ( $http_cookie ~* "comment_author_|wordpress_(?!test_cookie)|wp-postpass_" ) {
		set $no_cache_set 1;
		set $no_cache_get 1;
	}

	# If a request comes in with a X-Nginx-Cache-Purge: 1 header, do not grab from cache
	# But note that we will still store to cache
	# We use this to proactively update items in the cache!
	if ( $http_x_nginx_cache_purge ) {
		set $no_cache_get 1;
	}

	# For cached requests, tell client to hang on to them for 5 minutes
	if ( $no_cache_set = 0 ) {
	        expires 5m;
	}

	# fastcgi_no_cache means "Do not store this proxy response in the cache"
	fastcgi_no_cache $no_cache_set;
	# fastcgi_cache_bypass means "Do not look in the cache for this request"
	fastcgi_cache_bypass $no_cache_get;

	include        /etc/nginx/fastcgi_params;
	fastcgi_index  index.php;
	fastcgi_pass php;
	fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
	include fastcgi_params;
	try_files $uri @wordpress;
}

nginx.conf

user www-data;
worker_processes  8;

error_log  /var/log/nginx/error.log;
pid        /var/run/nginx.pid;

events {
    worker_connections  1024;
}

http {

	include mime.types;
	default_type       application/octet-stream;
	access_log         /var/log/nginx/access.log;
	sendfile           on;
	keepalive_timeout  3;
	client_max_body_size 13m;
	index              index.php index.html index.htm;

	# Upstream to abstract backend connection(s) for PHP.
	upstream php {
		server unix:/var/run/php5-fpm.sock;
	}
         
	include sites-enabled/*;
}

server_block.conf

## Microcache key_zone configuration.

fastcgi_cache_path /var/cache/nginx levels=1:2 keys_zone=microcache_fpm:10m inactive=5m max_size=500m;

server {
         ## Using default_server directive and catchall server_name to route all request 
         ## on port 80 to nginx.  This allows nginx to let WordPress multisite handle domain mapping

	listen 80  default_server;
        server_name  _;
	
	root /srv/www/public;
	
	index index.php index.html index.htm;
		
	include global.restrictions.conf;
	include global-wp-multi.conf;
	
}