The Linux Experiment

(This was originally posted here on my personal blog.)

I’ve recently been doing some testing in lua, and have been comparing the results to the EdgeLink Consulting CMS that we’ve designed in PHP. So far this solution is able to serve substantially more requests per second than our current CMS. However, we haven’t really spent much time optimizing the CMS. The goal is to have a working copy first before any optimizations are done. We’ve also been working on some eCommerce modules for the platform.

With all that being said, I’d like to post a quick tutorial on how I got this setup. It was quite the task. Although there was a tutorial I found to do the same task, it was a little bit confusing. My tutorial will have a lot of the same steps, with some minor adjustments. This tutorial is written at an intermediate level. Some trivial steps have been omitted.

NOTE: This has been tested with Debian 5.0.4 (Stable)

1. Install nginx
   

   apt-get install nginx

   We’ll have to do some modifications later on to add the FastCGI handler. For simplicity we will keep the web path to “/var/www/nginx-default” and listen on port 8081 in case you have another webserver running on port 80.

2. Install lua 5.1 (and WSAPI libraries)
   

   apt-get install lua5.1 liblua5.1-wsapi-fcgi-0 liblua5.1-coxpcall0 liblua5.1-filesystem0

   apt-get install liblua5.1-wsapi-doc

   Can’t do much testing without this. Note: The second line is not necessary if you are running Debian testing, and get the liblua5.1-wsapi-fcgi-1instead.

   EDIT: You’ll notice that I added in liblua5.1-filesystem0. Steve pointed out that there is a bug in liblua5.1-wsapi-fcgi-0. It doesn’t include it as a dependency. He reported this as a bug here, and it was fixed in liblua5.1-wsapi-fcgi-1.

3. Install spawn-fcgiIf you’re running Debian testing you may be able to get spawn-fcgi through the distribution, however, I just downloaded it and compiled from source.
   

   wget http://www.lighttpd.net/download/spawn-fcgi-1.6.3.tar.gz
   tar -xzvf spawn-fcgi-1.6.3.tar.gz
   cd spawn-fcgi-1.6.3.tar.gz
   ./configure
   make
   make install

4. Create a FastCGI Socket
   

   spawn-fcgi -F 4 -u www-data -s /var/run/nginx-fcgi.sock -P /var/run/nginx-fcgi.pid — /usr/bin/wsapi.fcgi

   For the sake of simplicity, we will just spawn it manually for now. If you’re feeling crafty you can add the above line to the start condition in/etc/init.d/nginx, and the line below to the stop condition. You can add both of them to restart.

   cat /var/run/nginx-fcgi.pid | xargs -n 1 kill

5. Create a lua file in /var/www/nginx-default/In this tutorial, use hello.lua. You can change this to whatever, you want but just make sure you make the modification in the nginx configuration below as well.
6. Edit /etc/nginx/sites-available/defaultNow let’s add the code that will point nginx to the correct file. For simplicity, we will simply point it to hello.lua. You can change this to anything, or simply modify the code to accept any *.lua file, as seen in the tutorial listed above. Here is the top of my default file:
   

   listen   8081 default;
   server_name  localhost;
   access_log  /var/log/nginx/localhost.access.log;

   location / {
   fastcgi_pass    unix:/var/run/nginx-fcgi.sock;
   fastcgi_param   SCRIPT_FILENAME “/var/www/nginx-default/hello.lua”;
   fastcgi_param   PATH_INFO       $request_uri;
   fastcgi_param   QUERY_STRING    $query_string;
   fastcgi_param   REQUEST_METHOD  $request_method;
   fastcgi_param   CONTENT_TYPE    $content_type;
   fastcgi_param   CONTENT_LENGTH  $content_length;
   }

7. Restart nginx
   

   /etc/init.d/nginx restart

8. Visit http://localhost:8081/Congratulations! You should now see hello.lua.