WordPress nginx proxy cache

If you are running WordPress on a VPS or dedicated server, you may want to install the nginx HTTP server to act as a proxy cache for WordPress.

This is a guide for building nginx from source so that 2 modules can be added.  The first module allows purging content from the proxy cache and the second module allows limiting the max concurrent requests to apache.

This guide assumes you are running:

• Ubuntu Server 10.04
• Apache HTTP Server Version 2.0

1. Configure ubuntu with needed development packages not installed by default and update/upgrade ubuntu

apt-get update
apt-get upgrade
apt-get install nginx build-essential libpcre3-dev libssl-dev zlib1g-dev
cd /usr/src/

2. Get latest nginx

wget http://www.nginx.org/download/nginx-0.8.52.tar.gz
tar -xvf nginx-*.tar.gz
rm nginx-*.tar.gz
mv nginx-* nginx-core

3. Get ngx_cache_purge module – adds ability to purge content from proxy cache

wget http://labs.frickle.com/files/ngx_cache_purge-1.2.tar.gz
tar -xvf ngx_cache_purge-*.tar.gz
rm ngx_cache_purge-*.tar.gz
mv ngx_cache_purge-* ngx_cache_purge

4. Get nginx-ey-balancer module – adds a request queue that allows limiting of concurrent requests to apache

wget https://github.com/ezmobius/nginx-ey-balancer/tarball/master -O nginx-ey-balancer.tar.gz
tar -xvf nginx-ey-balancer.tar.gz
rm nginx-ey-balancer.tar.gz
mv ry-nginx-ey-balancer-* nginx-ey-balancer

5. Patch and configure nginx

cd nginx-core
patch -p0 < ../nginx-ey-balancer/patches/nginx-0.8.32.patch
./configure --sbin-path=/usr/sbin --conf-path=/etc/nginx/nginx.conf
--error-log-path=/var/log/nginx/error.log --pid-path=/var/run/nginx.pid
--lock-path=/var/lock/nginx.lock --http-log-path=/var/log/nginx/access.log
--http-client-body-temp-path=/var/lib/nginx/body
--http-proxy-temp-path=/var/lib/nginx/proxy
--http-fastcgi-temp-path=/var/lib/nginx/fastcgi --with-debug
--with-http_stub_status_module --with-http_flv_module --with-http_ssl_module
--with-http_dav_module --with-http_gzip_static_module --with-ipv6
--add-module=/usr/src/ngx_cache_purge --add-module=/usr/src/nginx-ey-balancer

6. Build nginx

/etc/init.d/nginx stop
make && make install

7. Configure nginx

vim /etc/nginx/nginx.conf

# main nginx config
user www-data;
worker_processes 4; #based on number of CPU cores
error_log /var/log/nginx/error.log;
pid /var/run/nginx.pid;
events {
worker_connections  1024;
}
http {
server_tokens off;
include /etc/nginx/mime.types;
default_type application/octet-stream;
access_log /var/log/nginx/access.log;
client_body_temp_path /var/lib/nginx/body 1 2;
gzip_buffers 32 8k;
sendfile on;
keepalive_timeout 65;
tcp_nodelay on;
gzip on;
gzip_types text/css text/xml application/x-javascript
application/atom+xml text/plain application/rtf;
include /etc/nginx/sites-enabled/*;
}

8. Configure nginx server replacing listen with your public ip

vim /etc/nginx/sites-enabled/default

# server setup
proxy_cache_path /var/lib/nginx/cache levels=1:2 keys_zone=staticfilecache:180m
max_size=500m;
proxy_read_timeout 120;
proxy_send_timeout 120;
proxy_cache_key "$scheme://$host$request_uri";
upstream apache {
server 127.0.0.1:8080 weight=1 fail_timeout=120s;
max_connections 3;
}
server {
#Listen to your public IP
listen 192.168.1.98:80;
log_format custom '$host $uri $remote_addr [$time_local] '
'$status $bytes_sent [$request]';
access_log /var/log/nginx/access.log custom;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header Host $host;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Accept-Encoding "";
proxy_cache_valid 200 20m;
location / {
# If logged in, don't cache.
if ($http_cookie ~* "comment_author_|wordpress_(?!test_cookie)|wp-postpass_" ) {
set $do_not_cache 1;
}
proxy_no_cache $do_not_cache;
proxy_cache_bypass $do_not_cache;
proxy_cache staticfilecache;
proxy_pass http://apache;
proxy_cache_valid 200 20m;
}
location ~ /purge(/.*) {
proxy_cache_purge staticfilecache "$scheme://$host$1";
}
location ~* wp-.*.php|wp-admin {
proxy_pass http://apache;
}
location ~* .(jpg|png|gif|jpeg|css|js|mp3|wav|swf|mov|doc|pdf|xls|ppt|docx|pptx|xlsx|ico)$ {
proxy_cache staticfilecache;
proxy_pass http://apache;
proxy_cache_valid 200 120m;
expires 15552000;
}
location ~* /[^/]+/(feed|.xml)/? {
if ($http_cookie ~* "comment_author_|wordpress_(?!test_cookie)|wp-postpass_" ) {
set $do_not_cache 1;
}
proxy_no_cache $do_not_cache;
proxy_cache_bypass $do_not_cache;
proxy_cache staticfilecache;
proxy_pass http://apache;
proxy_cache_valid 200 45m;
expires 3600;
}
location = /50x.html {
root /var/www/nginx-default;
}
# No access to .htaccess files.
location ~ /.ht {
deny all;
}
}

9. Configure apache to listen on port 8080, also if you have expires rules set up in apache you will need to disable them for the proxy cache to work

vim /etc/apache2/ports.conf
vim /etc/apache2/sites-enabled/000-default

10. Restart nginx and apache

/etc/init.d/nginx restart
/etc/init.d/apache2 restart

11. Test

1. You should now be able to go to http://www.example.com/ and your page will be served and saved in the proxy cache
2. After visiting a page at http://www.example.com/blog/ you can clear the proxy cache by going to http://www.example.com/purge/blog/
3. If you are logged in to WordPress or have left a comment you will always receive a non-cached page from apache

12. You installed nginx via apt-get to take advantage of preconfigured directories, init scripts, etc.  Because of this you may want to prevent apt-get from upgrading nginx in the future.

vim /etc/apt/preferences.d/nginx

Package: nginx
Pin: version 0.8.52*
Pin-Priority: 1000

I hope this guide has been useful, if you have any questions or corrections please leave a comment.

The following were most valuable in providing the basis for the above guide.

• Nginx HTTP Server
• http://blogs.law.harvard.edu/djcp/2010/01/nginx-as-a-front-end-proxy-cache-for-wordpress/
• http://wordpress.org/extend/plugins/nginx-proxy-cache-integrator/installation/
• http://www.myatus.co.uk/2010/06/28/a-simplified-nginx-apache-combo-with-wordpress-support/
• http://mcnearney.net/blog/2010/2/28/compiling-nginx-cache-purging-support/