PHP Development Environment 2.0

London, UK

Thursday, December 31st 2009, 02:26 UTC

When moving the Xdebug website and my own website to a new server I had to pick a web server to serve the pages through PHP. Up to then I was still using Apache 1.3 with zero intentions to ever upgrade to any later version. I'd heard a lot about lighttpd and decided to give that a try—yes, that meant something that I didn't really know to well was going to run in a production environment. Unlike Apache, with lighttpd PHP doesn't run as a module, but instead you run it out of process with something called FastCGI.

On my development machine I was also running Apache 1.3 with PHP as static module embedded. If I want to test something with a different PHP version, I would start a different Apache daemon. When I had a quick look the other day, I found that I had about 28 different binaries named httpd-{Apache version}-{PHP version} ranging from PHP 4.1.2 to 6.0dev. Some of those I hadn't used for years.

All my PHP installations were installed with the same prefix (/usr/local) where the last built PHP version was available as php and additional versions as php-{version}. An annoyance with this is, is that I had to run make install in one of the PHP source directories before I could compile extensions against a different PHP version than the latest installed one. This combined with the enormous amount of httpds and the inability to run multiple versions of PHP at the same time prompted me to come up with something better: PHP Development Environment 2.0.

Multiple PHP Installations

The first thing I wanted to do was to make sure that each minor PHP version (5.1.x, 5.2.x, 5.3.x and 6.0.x) could be installed alongside each other, and that I could compile extensions to all of them without having to re-run make install. I did this by specifying --prefix=/usr/local/php/{PHP version} to the PHP configure call. At the same time, I also removed the --with-apache configure option and for PHP 5.1 and PHP 5.2 I added the --enable-fastcgi option which is default enabled for PHP 5.3 and PHP 6.0. The initial section of the configure invocation now looks like for the PHP 5.2 build:

./configure --prefix=/usr/local/php/5.2dev --enable-fastcgi \
  --with-gd  ...more configure options here...

Although /usr/local/bin is usually in the path, but /usr/local/php/5.2dev/bin is definitely not. The initial goal was to be able to easily switch between different PHP versions, so I added a snippet to my .bashrc that sets the correct PATH environment variable depending on the selected PHP version:

function pe () {
  version=$1
  shift

  if [ "$#" == "0" ]; then
    export PATH=/usr/local/php/${version}/bin:/usr/local/bin:/usr/bin:/bin
  else
    PATH=/usr/local/php/${version}/bin:$PATH $@
  fi
}

This bash function is then evoked like pe 5.3dev to set the path in such a way that php runs the PHP 5.3 binary, as well as additional tools such as pear, phpize (required to build extensions) and php-config. If you forget to call the pe function, then when running php you will encounter the warning bash: php: command not found. You could pick a default version if you wanted, but I prefer that I always have to be explicit about which PHP version I pick. Multiple install paths makes it easier to maintain multiple PHP installs, but it also means that you have to install tools such as PHP Unit for each of the installations.

Setting up Lighttpd

Now that I had multiple PHP installations, I could move on to setting up lighttpd. As I have mentioned, I never used lighttpd before and decided to take the easy way by installing it with apt-get install lighttpd. PHP works through the FastCGI interface with lighttpd which you can enable with lighttpd-enable-mod cgi fastcgi simple-vhost (I also enabled CGI and simple VHOSTing).

To enable PHP as FastCGI server, and to be able to run multiple versions at the same time, I modified the /etc/lighttpd/conf-enabled/10-fastcgi.