Adventures in IT

This technique was developed in the Ruby community and is a great way to approach caching partial views. In Ruby rendering views is more expensive than PHP, but this technique is worth understanding as it could be applied to data models and not just views. In the Ruby world Russian Doll caching is synonymous with key-based expiration caching.  I think it's useful to rather view the approach as being the blend of two ideas.  That's why I introduce key-based expiration separately. Personally I think Russian Dolls are a bit of a counter-intuitive analogy.  Real life Russian Dolls each contain one additional doll, but the power of this technique rests on the fact that "dolls" can contain many other "dolls".  I find the easiest way to think about it is to say that if a child node is invalidated then its siblings and their children are not affected.  When the parent is regenerated those sibling nodes do not need to be rendered again. Cache Invalidation ...

I searched for "dead clown" but all the pictures were too disturbing.  I suppose that's kind of like the experience of trying to get classic ASP up and running with todays libraries I'm having to work on a legacy site that runs on classic ASP.  The real challenge is trying to get the old code to run on my Ubuntu virtual machine. There is a lot of old advice on the web and most of it was based on much older software versions, but I persevered and have finally managed to get classic ASP running on Apache 2.4 in Ubuntu. The process will allow you to have a shot at getting your code running, but my best advice is to use a small Windows VM.  There's no guarantee that your code will actually compile and run using this solution, and the effort required is hardly worthwhile. The Apache module you're looking for is Apache::ASP.  You will need to build it manually and be prepared to copy pieces of it to your perl include directories.  You will also need to m...

I'm busy writing an application which is heavily dependent on personalized URLs.  Each visitor to the site will have a PURL which I need to communicate to the frontend so that my analytics tags can be associated with the user. Before I go any further I should note that I'm using  Piwik  as my analytics package, and it respects "Do Not Track" requests.  We're not using this to track people, but we are tying it to our clients existing database of their user interests. I want the process of identifying the user to be as magical as possible so that my controllers can stay nice and skinny.  Nobody likes a fat controller right? I decided to use middleware to trap all my web requests to assign a "responder" to the request.  Then I'll use a view composer to make sure that all of the output views have this information readily available. The only snag in this plan was that the Laravel documentation was a little sketchy on how to get the value of the ...

I'm busy migrating an existing server to the cloud and need to replicate the SFTP setup.  They're using a password to authenticate a user and then uploading data files for a web service to consume. YMMV - My use case is pretty specific to this legacy application so you'll need to give consideration to the directories you use. It took a surprising amount of reading to find a consistent set of instructions so I thought I should document the setup from start to finish. Firstly, I set up the group and user that I will be needing: groupadd sftponly useradd -G sftponly username passwd username Then I made a backup copy of and then edited /etc/ssh/sshd_config Right at the end of the file add the following: Match group sftponly ChrootDirectory /usr/share/nginx/html/website_directory/chroot X11Forwarding no AllowTcpForwarding no ForceCommand internal-sftp -d /uploads For some reason if this block appears before the UsePAM s...

The cost saving from reserving an EC2 instance is quite dramatic.  This morning I moved two web servers to reserved instances and am dropping my hosting cost by 64% for those servers. There isn't actually any effort required in moving your on demand EC2 instance to a reserved instance.  The only actual change is a billing change, you don't need to do anything in your instance configuration. The only important thing to remember is that you're reserving an instance in a particular availability zone.  The billing effect will only apply to instances launched in the same availability zone. Amazon will apply the discount of having a reserved instance to your invoice automatically.  They provide quite extensive documentation on reserved instances on their site ( here ).

I'm running an nginx server with php5-fpm and was always getting mail in /var/mail/root telling me that the cronjob running usr/lib/php5/maxlifetime was throwing warnings. The warnings were that: PHP Warning:  Module 'mcrypt' already loaded in Unknown on line 0 To fix this I had a look at the file and noticed that it was looping through the various sapi methods and running a command.  The line in the shell script looks like this: for sapi in apache2 apache2filter cgi fpm; do if [ -e /etc/php5/${sapi}/php.ini ]; then So I removed the mcrypt extension from my apache2 php.ini (/etc/php5/apache2/php.ini) and now the maxlifetime shell script runs without throwing warnings.

If you're using a staging server to test your Wordpress changes then you'll be deploying Wordpress to a new domain once your test team gives the go ahead. Unfortunately this can break Wordpress quite badly.  All the links in your content are essentially hard coded into the database content table.  There are settings in the options table that help Wordpress with deciding on redirects. Here are three useful sql statements that will make your life a little easier when migrating.  You can include them as part of your scripted deploy or just run them manually if you don't deploy Wordpress often. Edit them to suit your domain configuration, but they'll help you to change the links and settings in your database to point to the new domain.