I swore I wouldn't

After an invigorating year with a number of exciting and challenging projects, it is time to move on. I am taking a position with an established software provider in Vienna, VA. There are a number of very exciting projects that are on the roster, and I am eager to get started.

I recently encountered a cumbersome bug when trying to run a Ruby on Rails application (insoshi-based) on Ubuntu. Sporadically (but typically during events which involved attachment_fu) the server would crash and an error relating to “gc_sweep unknown data type” would show up in the log file. This did not occur in our development environments (Mac OSX) but only in UAT and prod environments (Ubuntu.) After much searching, stumbled upon a bug report that mentioned that this was a problem with ruby 1.8.7 versions prior to patch-level 300. Upgrading to 1.8.7p300 seems to have solved the problem. Will post a follow up if that turns out not to be the case.

I am in the process of migrating my office to Apple products. I needed a way to install iWorks and Parallels on my boss’s shiny new MacBook Air, but the MacBook Air has no optical drive, and we have not yet ordered an external drive. My assumption was that I would need to make an image and copy it over to her machine; I was wrong. After I launched Finder on her machine, I saw “Remote Disc” as one of her drive options. A little research revealed that I could enable “DVD or CD Sharing” from my Sharing Preferences pane. Doing so made my drive visible from her machine, and the installation went along without a hitch.

My time with CodeIgniter was fun, but it’s time to switch back to Rails. I enjoyed the ability to really get in and handle some of the code the way that I preferred, but overall I found that I missed a lot of the automagical things that happen with Rails. The biggest shortcoming for me was the lack of a real ActiveRecord model. I might give it a shot where it seems appropriate in the future, but for now I’m going back to Rails.

I received the error “The change you wanted was rejected” after I moved a rails app from one host to another.

Looking into the log file, the following error appears:

ActionController::InvalidAuthenticityToken (ActionController::InvalidAuthenticityToken):
/usr/lib/ruby/1.8/mongrel/rails.rb:76:in `process'
/usr/lib/ruby/1.8/mongrel/rails.rb:74:in `synchronize'
/usr/lib/ruby/1.8/mongrel/rails.rb:74:in `process'
/usr/lib/ruby/1.8/mongrel.rb:159:in `process_client'
/usr/lib/ruby/1.8/mongrel.rb:158:in `each'
/usr/lib/ruby/1.8/mongrel.rb:158:in `process_client'
/usr/lib/ruby/1.8/mongrel.rb:285:in `run'
/usr/lib/ruby/1.8/mongrel.rb:285:in `initialize'
/usr/lib/ruby/1.8/mongrel.rb:285:in `new'
/usr/lib/ruby/1.8/mongrel.rb:285:in `run'
/usr/lib/ruby/1.8/mongrel.rb:268:in `initialize'
/usr/lib/ruby/1.8/mongrel.rb:268:in `new'
/usr/lib/ruby/1.8/mongrel.rb:268:in `run'
/usr/lib/ruby/1.8/mongrel/configurator.rb:282:in `run'
/usr/lib/ruby/1.8/mongrel/configurator.rb:281:in `each'
/usr/lib/ruby/1.8/mongrel/configurator.rb:281:in `run'
/usr/lib/ruby/1.8/mongrel/command.rb:212:in `run'

Rendering /vol/sites/site/public/422.html (422 Unprocessable Entity)


Some further investigation revealed that there was an issue with how rails 2.3.8 was handling cookies.  I stumbled upon the following fix at https://rails.lighthouseapp.com/projects/8994/tickets/4690.

I used Ken Collins’ fix of adding his mongrel.rb (http://gist.github.com/471663) to config/initializers and now all is well.

I have been moving applications from my Rackspace host over to Amazon’s EC2 service.  Moving simple LAMP apps has been fairly cut and dry, but while moving a RoR app and accessing it through apache w/ mod_proxy, the html is delivered to the browser as plaintext.  If I access the app directly on mongrel’s port, it renders correctly.   So it appears that something with either my mod_proxy configuration, or something about how my EC2 instance is set up is causing the problem.


> curl -I http://linux.local:3000
HTTP/1.1 200 OK
Connection: close
Date: Thu, 15 Jul 2010 14:27:27 GMT
Content-Length: 0

> curl -I http://linux.local
HTTP/1.1 200 OK
Date: Thu, 15 Jul 2010 14:27:35 GMT
Via: 1.1 linux.local
Content-Type: text/plain


As you can see, when accessing the page through Apache/mod_proxy, the Content-Type that is returned is explicitly set as text/plain.

Update
This is a bit shoe-horned, but it works for right now. In the apache2.conf file, I changed the DefaultType from text/plain to text/html. The reason this solution “concerns” me is that on my other servers, (where this problem is not occurring) the DefaultType is also set to text/plain, but the html is output correctly.

From time to time you may need to flush the dns cache on your mac.  I had recently moved a site from one host to another, and while the nameservers at the various levels returned the new IP address, my browser still looked to the old IP address.

To resolve issues like this, (in Leopard) open a terminal and type in

> dscacheutil -flushcache


The same issue is resolved in 10.5.1 and earlier, open a terminal and type

> lookupd -flushcache


Last night I was forced to start working with CodeIgniter, a PHP web-framework, and I have to say that so far I am enjoying the experience.

CodeIgniter provides a simple framework that allows you to quickly get an application up and running.  The learning curve (so far) has been very low.  I like web-frameworks for projects. I have done a number of projects in Ruby on Rails, and I have dabbled in Django. Those have been pleasant experiences, but I prefer PHP as my preferred development language for most projects due to a number of reasons (not interested in jumping into that holy war right now.)

Up to this point, if I wanted to use a PHP framework, my choices were Zend and CakePHP. Zend is a monster. I’m sorry, I know a lot of developers swear by Zend, but I’m not one of them. Nobody “quickly” picks up Zend. Zend is so incredibly dense/bloated/abstracted that debugging something becomes an exercise that is more time consuming than the original problem that you were trying to solve. CakePHP felt too much like I was pretending to be Ruby on Rails, and there were so many hoops to jump through. And it was frequently a little “too magical.”

After exploring these different options, I wrote my own framework that took the parts of Ruby on Rails that I enjoyed, but kept the flexibility and familiarity of PHP. I have been using this for over a year now and it has served me well. I was pleased to find that the structure of CodeIgniter was almost identical to the structure of my own framework. This has made it a very easy switch for me.

Read the rest of this entry »

I encountered the following error when installing the mysql gem on a shiny new Macbook Pro running OS X Leopard.

Note: I have ~/.gem set as my GEM_HOME and GEM_PATH to avoid needing to sudo


> gem install mysql
Building native extensions. This could take a while...
ERROR: Error installing mysql:
ERROR: Failed to build gem native extension.

/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby extconf.rb
checking for mysql_query() in -lmysqlclient... no
checking for main() in -lm... yes
checking for mysql_query() in -lmysqlclient... no
checking for main() in -lz... yes
checking for mysql_query() in -lmysqlclient... no
checking for main() in -lsocket... no
checking for mysql_query() in -lmysqlclient... no
checking for main() in -lnsl... no
checking for mysql_query() in -lmysqlclient... no
checking for main() in -lmygcc... no
checking for mysql_query() in -lmysqlclient... no
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers. Check the mkmf.log file for more
details. You may need configuration options.


The workaround was fairly simple. Since I had installed MySQL from source the situation was resolved with a few command line options:


> export ARCHFLAGS="-arch x86_64"
> gem install mysql -- \
--with-mysql-dir=/usr/local/mysql \
--with-mysql-lib=/usr/local/mysql/lib \
--with-mysql-include=/usr/local/mysql/include \
--with-mysql-config=/usr/local/mysql/bin/mysql_config

Building native extensions. This could take a while...
Successfully installed mysql-2.8.1
1 gem installed


Hilarity below