# nginx and HHVM

[HHVM](http://hhvm.com/) is a faster alternative to PHP, in that it runs in a virtual machine
and uses just-in-time (JIT) compilation to achieve better performance over standard PHP.

Installation on Debian or Ubuntu is relatively straightforward, in that HHVM already provide
packages available to use:

Debian 7 (wheezy):

	wget -O - http://dl.hhvm.com/conf/hhvm.gpg.key | sudo apt-key add -
	echo deb http://dl.hhvm.com/debian wheezy main | sudo tee /etc/apt/sources.list.d/hhvm.list
	sudo apt-get update
	sudo apt-get install hhvm	

Ubuntu 14.04 (trusty):

	wget -O - http://dl.hhvm.com/conf/hhvm.gpg.key | sudo apt-key add -
	echo deb http://dl.hhvm.com/ubuntu trusty main | sudo tee /etc/apt/sources.list.d/hhvm.list
	sudo apt-get update
	sudo apt-get install hhvm

Please see [Prebuilt Packages for HHVM on HHVM wiki](https://github.com/facebook/hhvm/wiki/Prebuilt%20Packages%20for%20HHVM) for more ways to install.

Assuming you already have nginx installed, you can then run a script to enable support for
nginx and/or apache2 depending on whether they are installed or not:

	/usr/share/hhvm/install_fastcgi.sh

For nginx, this will place a file at `/etc/nginx/hhvm.conf` which you can use to include in
your nginx server definitions to provide support for php requests.

In order to get SilverStripe working, you need to create a custom configuration file.

In your `/etc/nginx/silverstripe.conf`, add this configuration:

	fastcgi_buffer_size 32k;
	fastcgi_busy_buffers_size 64k;
	fastcgi_buffers 4 32k;
	
	location / {
		try_files $uri /framework/main.php?url=$uri&$query_string;
	}
	
	error_page 404 /assets/error-404.html;
	error_page 500 /assets/error-500.html;
	
	location ^~ /assets/ {
		sendfile on;
		try_files $uri =404;
	}
	location ~ /(mysite|framework|cms)/.*\.(php|php3|php4|php5|phtml|inc)$ {
		deny all;
	}
	location ~ /\.. {
		deny all;
	}
	location ~ \.ss$ {
		satisfy any;
		allow 127.0.0.1;
		deny all;
	}
	location ~ web\.config$ {
		deny all;
	}
	location ~ \.ya?ml$ {
		deny all;
	}
	location ^~ /vendor/ {
		deny all;
	}
	location ~* /silverstripe-cache/ {
		deny all;
	}
	location ~* composer\.(json|lock)$ {
		deny all;
	}
	location ~* /(cms|framework)/silverstripe_version$ {
		deny all;
	}

The above script passes all non-static file requests to `/framework/main.php` in the webroot which relies on
`hhvm.conf` being included prior so that php requests are handled.

Now in your nginx `server` configuration you can then include the `hhvm.conf` and `silverstripe.conf` files
to complete the configuration required for PHP/HHVM and SilverStripe.

e.g. `/etc/nginx/sites-enabled/mysite`:

	server {
		listen 80;
		root /var/www/mysite;
		server_name www.mysite.com;
	
		error_log /var/log/nginx/mysite.error.log;
		access_log /var/log/nginx/mysite.access.log;
	
		include /etc/nginx/hhvm.conf;
		include /etc/nginx/silverstripe.conf;
	}

For more information on nginx configuration, please see the [nginx installation](nginx) page.