Wordpress FastCGI Cache

Quick tool utilities to manage a fastcgi cache enabled server

Nginx Configuration

In order to setup Nginx to use fast cgi cache we must configure Nginx in a couple of different places. This plugin assumes that the fast cgi cache will be located in the directory /var/cache/nginxfastcgi

So first lets make that directory on the server:

mkdir -p /var/cache/nginxfastcgi

Also create a global directory in your nginx etc directory:

mkdir /etc/nginx/global

Make sure you set the ownership to whatever user your nginx user is running under. Run the following and replace owner_name with the username that nginx uses to run under:

chown -R owner_name:owner_name /var/cache/nginxfastcgi

After that lets create a file called /etc/nginx/global/wordpress_cache.conf and place the below code inside of it. You can change it where you like, however be cautious of the $fastcgi_skipcache stuff. Also make sure to update your fast cgi socket file location to where php-fpm places its socket.

# example FastCGI cache exception rules
set $fastcgi_skipcache 0;
if ($http_cookie ~ "users_login_cookie") {
  set $fastcgi_skipcache 1;
}

if ($request_method = POST) {
    set $fastcgi_skipcache 1;
}

if ($query_string != "") {
    set $fastcgi_skipcache 1;
}

if ($request_uri ~* "/wp-admin/|/xmlrpc.php|wp-.*.php|/feed/|index.php|sitemap(_index)?.xml") {
    set $fastcgi_skipcache 1;
}

if ($http_cookie ~* "comment_author|wordpress_[a-f0-9]+|wp-postpass|wordpress_no_cache|wordpress_logged_in") {
    set $fastcgi_skipcache 1;
}

if ( $request_uri ~ "/wp/wp-login.php" ) {
  set $fastcgi_skipcache 1;
}

if ( $request_uri ~ "/wp/wp-admin" ) {
  set $fastcgi_skipcache 1;
}

# Global restrictions configuration file.
# Designed to be included in any server {} block.</p>
location = /favicon.ico {
    log_not_found off;
    access_log off;
}

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).
# Keep logging the requests to parse later (or to pass to firewall utilities such as fail2ban)
location ~ /\. {
    deny all;
}

location /admin {
    return 301 /wp/wp-admin;
}

# Deny access to any files with a .php extension in the uploads directory
# Works in sub-directory installs and also in multisite network
# Keep logging the requests to parse later (or to pass to firewall utilities such as fail2ban)
location ~* /(?:uploads|files)/.*\.php$ {
    deny all;
}

# WordPress single blog rules.
# Designed to be included in any server {} block.

# This order might seem weird - this is attempted to match last if rules below fail.
# http://wiki.nginx.org/HttpCoreModule
location / {
    add_header 'Access-Control-Allow-Origin' '*';
    add_header 'Accept-Encoding' 'gzip';
    try_files $uri $uri/ /index.php?$args;
}

# Add trailing slash to */wp-admin requests.
rewrite /wp-admin$ $scheme://$host$uri/ permanent;

# Directives to send expires headers and turn off 404 error logging.
location ~* ^.+\.(ogg|ogv|svg|svgz|eot|otf|woff|mp4|ttf|rss|atom|jpg|jpeg|gif|png|ico|zip|tgz|gz|rar|bz2|doc|xls|exe|ppt|tar|mid|midi|wav|bmp|rtf)$ {
       access_log off; log_not_found off; expires max;
}

# Pass all .php files onto a php-fpm/php-fcgi server.
location ~ [^/]\.php(/|$) {
    fastcgi_split_path_info ^(.+?\.php)(/.*)$;
    if (!-f $document_root$fastcgi_script_name) {
        return 404;
    }

    fastcgi_buffers 8 16k;
    fastcgi_buffer_size 32k;

    add_header X-Cache $upstream_cache_status;
    fastcgi_cache fastcgicache;
    fastcgi_cache_bypass $fastcgi_skipcache;
    fastcgi_no_cache $fastcgi_skipcache;        

    # This is a robust solution for path info security issue and works with "cgi.fix_pathinfo = 1" in /etc/php.ini (default)
    fastcgi_pass unix:/var/run/php-fpm/php-fpm.sock;
    fastcgi_index index.php;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    include fastcgi_params;
    fastcgi_param APP_ENV prod;
    fastcgi_read_timeout 600;
}

After creating your global wordpress cache configuration you will need to define your cache system in nginx by adding a file /etc/nginx/global/cache.conf and adding the following lines:

fastcgi_cache_path /var/cache/nginxfastcgi levels=1:2 keys_zone=fastcgicache:5m inactive=5m max_size=64m;
fastcgi_cache_key $scheme$request_method$host$request_uri;
# note: can also use HTTP headers to form the cache key, e.g.
fastcgi_cache_lock on;
fastcgi_cache_use_stale error timeout invalid_header updating http_500;
fastcgi_cache_valid 5m;
fastcgi_ignore_headers Cache-Control Expires Set-Cookie;

proxy_buffer_size   128k;
proxy_buffers   4 256k;
proxy_busy_buffers_size   256k;

And finally after that file is created you must include it in the nginx configuration by adding the following line to /etc/nginx/nginx.conf below client_max_body_size:

include             /etc/nginx/global/cache.conf;

After that you must replace your fast cgi block with the following under any wordpress site configuration:

include             global/wordpress_cache.conf;