geekery

Moving wordpress to another host

Theo, Leave a comment

If you’ve been following my blog for awhile, you might have noticed I moved this blog from www.theodorenguyen-cao.com to theodorenguyen-cao.com as it was more fitting domain. I originally just registered the domain, added the DNS record, and updated my apache config to have theodorenguyen-cao.com to be an server alias to www.theodorenguyen-cao.com.

This allowed requests to www.theodorenguyen-cao.com/* and theodorenguyen-cao/* respond with the same content. I thought I was done. I discovered this wasn’t the case when I saw www.theodorenguyen-cao.com as a direct traffic source in my google analytics for theodorenguyen-cao.com. To fix the screwed up analytics, I needed to make it so that all requests that go to www.theodorenguyen-cao.com are permanently redirected (301) to theodorenguyen-cao.com.

To do this I had to apply an Apache mod_alias redirect directive as such:

<VirtualHost *:80>
        VirtualDocumentRoot /var/www/blog
        ServerName www.theodorenguyen-cao.com
        Redirect permanent / https://www.theodorenguyen-cao.com/
        ErrorLog /var/log/apache2/wp-error.log
        TransferLog /var/log/apache2/wp-access.log
</VirtualHost>

The virtual host for theodorenguyen-cao.com looks like:

<VirtualHost *:80>
    VirtualDocumentRoot /var/www/blog
    ServerName www.theodorenguyen-cao.com
    ServerAlias theodorenguyen-cao.com
    CustomLog /var/log/apache2/theodorenguyen-cao.com_access.log Combined
    ErrorLog /var/log/apache2/theodorenguyen-cao_error.log
</VirtualHost>

At first I thought this would only fix the simple case of www.theodorenguyen-cao.com redirecting to theodorenguyen-cao.com, but blog.notepath.com/foobar not being translated to theodorenguyen-cao.com/foobar. However, this does exactly what I want. All www.theodorenguyen-cao.com URLs will be replaced with theodorenguyen-cao.com URLs. Old bookmarks will simply redirect to a theodorenguyen-cao.com URL and not 404.

Success!

I’m still waiting to see if Google will update the search result links that point to www.theodorenguyen-cao.com to be theodorenguyen-cao.com URLs.

Moving wordpress to another host

Using validates_presence_of on a boolean field? Should use validates_inclusion_of!

Theo, 3 Comments

rsvp.theoandpat.com had boolean flag to marked whether or not a visitor was going to be able to make it to our wedding. Unfortunately, if you selected you were not able to make it and submit the form, the application would return saying it could not process your submission because you have to say that you are going to make it. I argued, this is an RSVP form so you have to accept if you are RSVPing. That’s the point of the RSVP! Only people RSVP would bother submitting the form!  Pat wasn’t too happy about that and ask/told me to fix it. 

Digging into it, it turns out the way  for validates_presence_of relies on Object#blank which of course when sent

false.blank? # returns true

Reading up on the documentation, it is suggested to use validates_inclusion_of when dealing with booleans.

The one line change solved the problem:

validates_inclusion_of :accepted, :in => [true, false]
Using validates_presence_of on a boolean field? Should use validates_inclusion_of!

tiny URLs? HA! diminutive URLs for the win!

TheoLeave a comment

Inspired by a discussion of URL shortening, I took a weekend and implemented one of my own. When thinking about tiny URLs, a quote always came to mind.

Don’t use a big word where a diminutive one will suffice.

So after finding out the domain was available, diminutiveurl.com was born. Yes, it’s poking a little fun at the idea of a tiny url but it was fun to hack on. It’s very minimilistic at this point but I hope to add some interesting features.

diminutiveurl.com

For no other reason than to build something, I hope you enjoy it! I am glad to present diminitiveurl.com! Please let me know what you think.

tiny URLs? HA! diminutive URLs for the win!

Setting up Phusion Passenger (mod_rails) with Capistrano support

Theo, , , 1 Comment

I had heard of mod_rails awhile back but never had the time to take a closer look at it. While setting up a new rails app, I was getting frustrated with all of the configuration I needed to do to get the mongrel clusters and proxy balancers setup. So I decided to give passenger a chance. I’m a fan now 🙂

The process was dead simple.

  1. Install the passenger gem 
    sudo gem install passenger
  2. Install passenger as an Apache module 
    passenger-install-apache2-module
  3. Load the passenger apache module by editing the Apache config 
    LoadModule passenger_module /usr/lib/ruby/gems/1.8/gems/passenger-2.0.5/ext/apache2/mod_passenger.so
PassengerRoot /usr/lib/ruby/gems/1.8/gems/passenger-2.0.5
PassengerRuby /usr/bin/ruby1.8
  4. Restart Apache

If all things went well, you have everything installed you need. If there were some missing dependencies, you should be presented with how to install those dependencies.

In the installation output, it tells you how to mod_railsify your apps by creating a vhost as such:

<VirtualHost *:80>
    ServerName www.mywebsite.com
    DocumentRoot /home/deploy/mywebsite/public
</VirtualHost>

That’s it! No more of this proxy balancer and mongrel_cluster.yml configuration.

There’s some magic going on in the background. As requests come in, passenger will spin up more application instances. For more tweaking your configuration options check out the user guide.

Go to your website and you should see your rails app up and running.

So now we have your app up and running, how do we update or restart our app? Passenger provides two ways for us to do this.

The first is whenever apache is restarted, your application is restarted.

The second way allows us to restart a specified application without affecting Apache. Whenever passenger detects tmp/restart.txt, it will restart the application instances for us. We can integrate this into our Capistrano deploy flow by adding the following our config/deploy.rb

namespace :passenger do
  desc "Restart Application"
  task :restart do
    run "touch #{current_path}/tmp/restart.txt"
  end
end

after :deploy, "passenger:restart"

This will create that restart.txt after the cap:deploy task gets executed, causing the application to restart.

Finally, passenger comes with some pretty useful utilities.

Check out passenger-status which produces output showing current passenger server statuses.

Sample output: 

----------- General information -----------
max      = 6
count    = 1
active   = 0
inactive = 1
Using global queue: no
Waiting on global queue: 0

----------- Applications -----------
/home/deploy/www.myapp.com/releases/20081206183156: 
  PID: 30784     Sessions: 0

Another utility passenger-memory-status gives you insight into how much memory is being used by apache and passenger.

Sample output:

-------------- Apache processes ---------------
PID    PPID   Threads  VMSize    Private  Name
-----------------------------------------------
12841  1      1        225.9 MB  0.0 MB   /usr/sbin/apache2 -k start
28294  12841  1        248.4 MB  21.4 MB  /usr/sbin/apache2 -k start
28300  12841  1        243.7 MB  0.5 MB   /usr/sbin/apache2 -k start
28306  12841  1        248.4 MB  4.4 MB   /usr/sbin/apache2 -k start
28357  12841  1        249.1 MB  19.8 MB  /usr/sbin/apache2 -k start
29400  12841  1        249.4 MB  3.7 MB   /usr/sbin/apache2 -k start
29788  12841  1        249.3 MB  21.7 MB  /usr/sbin/apache2 -k start
29834  12841  1        245.8 MB  18.9 MB  /usr/sbin/apache2 -k start
29836  12841  1        245.8 MB  9.3 MB   /usr/sbin/apache2 -k start
29868  12841  1        245.8 MB  2.4 MB   /usr/sbin/apache2 -k start
29870  12841  1        246.5 MB  5.2 MB   /usr/sbin/apache2 -k start
### Processes: 11
### Total private dirty RSS: 107.44 MB

--------- Passenger processes ----------
PID    Threads  VMSize    Private  Name
----------------------------------------
28031  10       15.3 MB   0.1 MB   /usr/lib/ruby/gems/1.8/gems/passenger-2.0.5/ext/apache2/ApplicationPoolServerExecutable 0 /usr/lib/ruby/gems/1.8/gems/passenger-2.0.5/bin/passenger-spawn-server  /usr/bin/ruby1.8  /tmp/passenger_status.12841.fifo
28032  2        48.7 MB   0.6 MB   Passenger spawn server
29161  1        114.8 MB  0.7 MB   Passenger FrameworkSpawner: 2.1.2
30461  1        122.8 MB  32.3 MB  Passenger ApplicationSpawner: /home/deploy/www.myapp.com/releases/20081206183156
30784  1        129.3 MB  33.4 MB  Rails: /home/deploy/www.myapp.com/releases/20081206183156
### Processes: 5
### Total private dirty RSS: 67.08 MB

Pretty sweet.

Setting up Phusion Passenger (mod_rails) with Capistrano support

2 ways to fix transparent PNG files in IE6

Theo, Leave a comment

I fired up Photoshop for the first time in a long time. I created a transparent PNG for an image that would be used as a CSS background-image. It keeps displaying with a gray background even though the page background color was something else.

This is a pretty well documented bug. Luckily, there are a couple of ways to fix this.

Here are my two favorites:

The first solution is well documented:

Download iepngfix.zip. The development version 2.0 Alpha 3 has support for background position and repeat. Extract the zip and copy iepngfix.htc and blank.gif somewhere. I put in under stylesheets.

Add the following snippet to your CSS stylesheet:

img { 
	behavior: url(/stylesheets/iepngfix.htc); 
}

And you’re done! Hit refresh in IE6 and transparent PNG images should render correctly now.

You can add apply this fix to other elements that may be using PNG images as CSS background images as such:

img, #logo { 
	behavior: url(/stylesheets/iepngfix.htc); 
}

where logo is a div that has a background-image that is a transparent PNG.

Note: If you are using v2.0 and want to take advantage of background-repeat and position support, copy iepngfix_tilebg.js to your javascripts folder and include the js file in the HTML files you need it for.

The second way to fix this is to get everyone off IE6 but I guess that’s just wishful thinking…

2 ways to fix transparent PNG files in IE6

undefined local variable or method `remote_gemspecs’

Theo, 12 Comments

I decided I wanted to dedicate some time this weekend working on some side projects. Of course before I start, I needed to get the latest and greatest updates so I ran gem update and got the following error

theo@theo~/dev $ sudo gem update
Updating installed gems
...
Updating rubygems-update
Successfully installed rubygems-update-1.3.1
ERROR:  While executing gem ... (NameError)
    undefined local variable or method `remote_gemspecs' for #

Reading the release notes:

NOTE: RubyGems 1.1 and 1.2 have problems upgrading when there is no
rubygems-update installed. You will need to follow the second set of update
instructions if you see “Nothing to update”.

shows that we need to install and run the rubygem-update gem to get this fixed

  theo@theo~/dev $ sudo gem install rubygems-update
Successfully installed rubygems-update-1.3.1
1 gem installed
  theo@theo~/dev $ sudo update_rubygems 
Installing RubyGems 1.3.1
mkdir -p /Library/Ruby/Site/1.8
mkdir -p /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin
install -c -m 0644 rbconfig/datadir.rb /Library/Ruby/Site/1.8/rbconfig/datadir.rb
install -c -m 0644 rubygems/builder.rb /Library/Ruby/Site/1.8/rubygems/builder.rb
install -c -m 0644 rubygems/command.rb /Library/Ruby/Site/1.8/rubygems/command.rb
install -c -m 0644 rubygems/command_manager.rb /Library/Ruby/Site/1.8/rubygems/command_manager.rb
install -c -m 0644 rubygems/commands/build_command.rb /Library/Ruby/Site/1.8/rubygems/commands/build_command.rb
install -c -m 0644 rubygems/commands/cert_command.rb /Library/Ruby/Site/1.8/rubygems/commands/cert_command.rb
install -c -m 0644 rubygems/commands/check_command.rb /Library/Ruby/Site/1.8/rubygems/commands/check_command.rb
install -c -m 0644 rubygems/commands/cleanup_command.rb /Library/Ruby/Site/1.8/rubygems/commands/cleanup_command.rb
install -c -m 0644 rubygems/commands/contents_command.rb /Library/Ruby/Site/1.8/rubygems/commands/contents_command.rb
install -c -m 0644 rubygems/commands/dependency_command.rb /Library/Ruby/Site/1.8/rubygems/commands/dependency_command.rb
install -c -m 0644 rubygems/commands/environment_command.rb /Library/Ruby/Site/1.8/rubygems/commands/environment_command.rb
install -c -m 0644 rubygems/commands/fetch_command.rb /Library/Ruby/Site/1.8/rubygems/commands/fetch_command.rb
install -c -m 0644 rubygems/commands/generate_index_command.rb /Library/Ruby/Site/1.8/rubygems/commands/generate_index_command.rb
install -c -m 0644 rubygems/commands/help_command.rb /Library/Ruby/Site/1.8/rubygems/commands/help_command.rb
install -c -m 0644 rubygems/commands/install_command.rb /Library/Ruby/Site/1.8/rubygems/commands/install_command.rb
install -c -m 0644 rubygems/commands/list_command.rb /Library/Ruby/Site/1.8/rubygems/commands/list_command.rb
install -c -m 0644 rubygems/commands/lock_command.rb /Library/Ruby/Site/1.8/rubygems/commands/lock_command.rb
install -c -m 0644 rubygems/commands/mirror_command.rb /Library/Ruby/Site/1.8/rubygems/commands/mirror_command.rb
install -c -m 0644 rubygems/commands/outdated_command.rb /Library/Ruby/Site/1.8/rubygems/commands/outdated_command.rb
install -c -m 0644 rubygems/commands/pristine_command.rb /Library/Ruby/Site/1.8/rubygems/commands/pristine_command.rb
install -c -m 0644 rubygems/commands/query_command.rb /Library/Ruby/Site/1.8/rubygems/commands/query_command.rb
install -c -m 0644 rubygems/commands/rdoc_command.rb /Library/Ruby/Site/1.8/rubygems/commands/rdoc_command.rb
install -c -m 0644 rubygems/commands/search_command.rb /Library/Ruby/Site/1.8/rubygems/commands/search_command.rb
install -c -m 0644 rubygems/commands/server_command.rb /Library/Ruby/Site/1.8/rubygems/commands/server_command.rb
install -c -m 0644 rubygems/commands/sources_command.rb /Library/Ruby/Site/1.8/rubygems/commands/sources_command.rb
install -c -m 0644 rubygems/commands/specification_command.rb /Library/Ruby/Site/1.8/rubygems/commands/specification_command.rb
install -c -m 0644 rubygems/commands/stale_command.rb /Library/Ruby/Site/1.8/rubygems/commands/stale_command.rb
install -c -m 0644 rubygems/commands/uninstall_command.rb /Library/Ruby/Site/1.8/rubygems/commands/uninstall_command.rb
install -c -m 0644 rubygems/commands/unpack_command.rb /Library/Ruby/Site/1.8/rubygems/commands/unpack_command.rb
install -c -m 0644 rubygems/commands/update_command.rb /Library/Ruby/Site/1.8/rubygems/commands/update_command.rb
install -c -m 0644 rubygems/commands/which_command.rb /Library/Ruby/Site/1.8/rubygems/commands/which_command.rb
install -c -m 0644 rubygems/config_file.rb /Library/Ruby/Site/1.8/rubygems/config_file.rb
install -c -m 0644 rubygems/custom_require.rb /Library/Ruby/Site/1.8/rubygems/custom_require.rb
install -c -m 0644 rubygems/defaults.rb /Library/Ruby/Site/1.8/rubygems/defaults.rb
install -c -m 0644 rubygems/dependency.rb /Library/Ruby/Site/1.8/rubygems/dependency.rb
install -c -m 0644 rubygems/dependency_installer.rb /Library/Ruby/Site/1.8/rubygems/dependency_installer.rb
install -c -m 0644 rubygems/dependency_list.rb /Library/Ruby/Site/1.8/rubygems/dependency_list.rb
install -c -m 0644 rubygems/digest/digest_adapter.rb /Library/Ruby/Site/1.8/rubygems/digest/digest_adapter.rb
install -c -m 0644 rubygems/digest/md5.rb /Library/Ruby/Site/1.8/rubygems/digest/md5.rb
install -c -m 0644 rubygems/digest/sha1.rb /Library/Ruby/Site/1.8/rubygems/digest/sha1.rb
install -c -m 0644 rubygems/digest/sha2.rb /Library/Ruby/Site/1.8/rubygems/digest/sha2.rb
install -c -m 0644 rubygems/doc_manager.rb /Library/Ruby/Site/1.8/rubygems/doc_manager.rb
install -c -m 0644 rubygems/exceptions.rb /Library/Ruby/Site/1.8/rubygems/exceptions.rb
install -c -m 0644 rubygems/ext/builder.rb /Library/Ruby/Site/1.8/rubygems/ext/builder.rb
install -c -m 0644 rubygems/ext/configure_builder.rb /Library/Ruby/Site/1.8/rubygems/ext/configure_builder.rb
install -c -m 0644 rubygems/ext/ext_conf_builder.rb /Library/Ruby/Site/1.8/rubygems/ext/ext_conf_builder.rb
install -c -m 0644 rubygems/ext/rake_builder.rb /Library/Ruby/Site/1.8/rubygems/ext/rake_builder.rb
install -c -m 0644 rubygems/ext.rb /Library/Ruby/Site/1.8/rubygems/ext.rb
install -c -m 0644 rubygems/format.rb /Library/Ruby/Site/1.8/rubygems/format.rb
install -c -m 0644 rubygems/gem_openssl.rb /Library/Ruby/Site/1.8/rubygems/gem_openssl.rb
install -c -m 0644 rubygems/gem_path_searcher.rb /Library/Ruby/Site/1.8/rubygems/gem_path_searcher.rb
install -c -m 0644 rubygems/gem_runner.rb /Library/Ruby/Site/1.8/rubygems/gem_runner.rb
install -c -m 0644 rubygems/indexer.rb /Library/Ruby/Site/1.8/rubygems/indexer.rb
install -c -m 0644 rubygems/install_update_options.rb /Library/Ruby/Site/1.8/rubygems/install_update_options.rb
install -c -m 0644 rubygems/installer.rb /Library/Ruby/Site/1.8/rubygems/installer.rb
install -c -m 0644 rubygems/local_remote_options.rb /Library/Ruby/Site/1.8/rubygems/local_remote_options.rb
install -c -m 0644 rubygems/old_format.rb /Library/Ruby/Site/1.8/rubygems/old_format.rb
install -c -m 0644 rubygems/package/f_sync_dir.rb /Library/Ruby/Site/1.8/rubygems/package/f_sync_dir.rb
install -c -m 0644 rubygems/package/tar_header.rb /Library/Ruby/Site/1.8/rubygems/package/tar_header.rb
install -c -m 0644 rubygems/package/tar_input.rb /Library/Ruby/Site/1.8/rubygems/package/tar_input.rb
install -c -m 0644 rubygems/package/tar_output.rb /Library/Ruby/Site/1.8/rubygems/package/tar_output.rb
install -c -m 0644 rubygems/package/tar_reader/entry.rb /Library/Ruby/Site/1.8/rubygems/package/tar_reader/entry.rb
install -c -m 0644 rubygems/package/tar_reader.rb /Library/Ruby/Site/1.8/rubygems/package/tar_reader.rb
install -c -m 0644 rubygems/package/tar_writer.rb /Library/Ruby/Site/1.8/rubygems/package/tar_writer.rb
install -c -m 0644 rubygems/package.rb /Library/Ruby/Site/1.8/rubygems/package.rb
install -c -m 0644 rubygems/platform.rb /Library/Ruby/Site/1.8/rubygems/platform.rb
install -c -m 0644 rubygems/remote_fetcher.rb /Library/Ruby/Site/1.8/rubygems/remote_fetcher.rb
install -c -m 0644 rubygems/require_paths_builder.rb /Library/Ruby/Site/1.8/rubygems/require_paths_builder.rb
install -c -m 0644 rubygems/requirement.rb /Library/Ruby/Site/1.8/rubygems/requirement.rb
install -c -m 0644 rubygems/rubygems_version.rb /Library/Ruby/Site/1.8/rubygems/rubygems_version.rb
install -c -m 0644 rubygems/security.rb /Library/Ruby/Site/1.8/rubygems/security.rb
install -c -m 0644 rubygems/server.rb /Library/Ruby/Site/1.8/rubygems/server.rb
install -c -m 0644 rubygems/source_index.rb /Library/Ruby/Site/1.8/rubygems/source_index.rb
install -c -m 0644 rubygems/source_info_cache.rb /Library/Ruby/Site/1.8/rubygems/source_info_cache.rb
install -c -m 0644 rubygems/source_info_cache_entry.rb /Library/Ruby/Site/1.8/rubygems/source_info_cache_entry.rb
install -c -m 0644 rubygems/spec_fetcher.rb /Library/Ruby/Site/1.8/rubygems/spec_fetcher.rb
install -c -m 0644 rubygems/specification.rb /Library/Ruby/Site/1.8/rubygems/specification.rb
install -c -m 0644 rubygems/test_utilities.rb /Library/Ruby/Site/1.8/rubygems/test_utilities.rb
install -c -m 0644 rubygems/timer.rb /Library/Ruby/Site/1.8/rubygems/timer.rb
install -c -m 0644 rubygems/uninstaller.rb /Library/Ruby/Site/1.8/rubygems/uninstaller.rb
install -c -m 0644 rubygems/user_interaction.rb /Library/Ruby/Site/1.8/rubygems/user_interaction.rb
install -c -m 0644 rubygems/validator.rb /Library/Ruby/Site/1.8/rubygems/validator.rb
install -c -m 0644 rubygems/version.rb /Library/Ruby/Site/1.8/rubygems/version.rb
install -c -m 0644 rubygems/version_option.rb /Library/Ruby/Site/1.8/rubygems/version_option.rb
install -c -m 0644 rubygems.rb /Library/Ruby/Site/1.8/rubygems.rb
install -c -m 0644 ubygems.rb /Library/Ruby/Site/1.8/ubygems.rb
cp gem /tmp/gem
install -c -m 0755 /tmp/gem /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/gem
rm /tmp/gem
rm -f /Users/theo/.gem/source_cache
rm -f /Library/Ruby/Gems/1.8/source_cache
Removing old RubyGems RDoc and ri
rm -rf /Library/Ruby/Gems/1.8/doc/rubygems-1.2.0
Installing rubygems-1.3.1 ri into /Library/Ruby/Gems/1.8/doc/rubygems-1.3.1/ri
Installing rubygems-1.3.1 rdoc into /Library/Ruby/Gems/1.8/doc/rubygems-1.3.1/rdoc

------------------------------------------------------------------------------

= Announce: RubyGems Release 1.3.0

NOTE:  RubyGems 1.1 and 1.2 have problems upgrading when there is no
rubygems-update installed.  You will need to follow the second set of update
instructions if you see "Nothing to update".

Release 1.3.0 fixes some bugs.

Bugs fixed:

* Disregard ownership of ~ under Windows while creating ~/.gem.  Fixes
  issues related to no uid support under Windows.
* Fix requires for Gem::inflate, Gem::deflate, etc.
* Make Gem.dir respect :gemhome value from config.  (Note: this feature may be
  removed since it is hard to implement on 1.9.)
* Kernel methods are now private.  Patch #20801 by Stefan Rusterholz.
* Gem::location_of_caller now behaves on Windows.  Patch by Daniel Berger.
* Silence PATH warning.

Deprecation Notices:

* Gem::manage_gems will be removed on or after March 2009.

For a full list of changes to RubyGems and the contributor for each change, see
the ChangeLog file.

Special thanks to Chad Wooley for backwards compatibility testing and Luis
Lavena for continuing windows support.

== How can I get RubyGems?

NOTE:  If you have installed RubyGems using a package system you may want to
install a new RubyGems through the same packaging system.

If you have a recent version of RubyGems (0.8.5 or later), then all
you need to do is:

  $ gem update --system   (you might need to be admin/root)

NOTE:  RubyGems 1.1 and 1.2 have problems upgrading when there is no
rubygems-update installed.  You will need to follow the second set of update
instructions if you see "Nothing to update".

NOTE: You may have to run the command twice if you have any previosly
installed rubygems-update gems.

If you have an older version of RubyGems installed, then you can still
do it in two steps:

  $ gem install rubygems-update  (again, might need to be admin/root)
  $ update_rubygems              (... here too)

If you don't have any gems install, there is still the pre-gem
approach to getting software ... doing it manually:

1. DOWNLOAD FROM: http://rubyforge.org/frs/?group_id=126
2. UNPACK INTO A DIRECTORY AND CD THERE
3. INSTALL WITH:  ruby setup.rb  (you may need admin/root privilege)

== To File Bugs

The RubyGems bug tracker can be found on RubyForge at:
http://rubyforge.org/tracker/?func=add&group_id=126&atid=575

When filing a bug, `gem env` output will be helpful in diagnosing the issue.

If you find a bug where RubyGems crashes, please provide debug output. You can
do that with `gem --debug the_command`.

== Thanks

Keep those gems coming!

-- Jim & Chad & Eric (for the RubyGems team)


------------------------------------------------------------------------------

RubyGems installed the following executables:
	/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/gem

If `gem` was installed by a previous RubyGems installation, you may need
to remove it by hand.
undefined local variable or method `remote_gemspecs’

Pair Programming > Code Reviews

Theo3 Comments

With the rise in popularity of agile software methodologies, the practice of formal code reviews has been often put against pair programming. There are proponents for both and some even recommend practicing both.

As time goes on, I’ve been able to do a little bit of both and I’ve developed a strong preference for pair programming over code reviews.

With code reviews, you get one or more other persons to review the code you just wrote and feel ready is to be checked in, deployed, or whatever the next step is. These reviews can be very formal or just as simple as a line-by-line walk through the code. The goal is to find any bugs or fixes before the code gets to the next step. This is very analogous to the writer/editor/publisher workflow (kind of like this blog entry). Writer writes the article, editor proofreads, and the article gets published. Programmer writes the code, other developers review the code, and the code gets deployed. It almost seems like the idea of code reviews came out of software methodologies like the Waterfall model. Everything is very sequential and done in distinct stages.

In pair programming, the focus is on developing “good” code the first time around. We do this by having more than one pair of eyes on the working code as it is being written. One person is the “driver” who is writing the code and the other is the guide or observer who is verifying the code being written and thinking of potential improvements. The developers switch roles whenever it makes sense which in many cases causes one developer to immediate use or have to work with the code that was written by their partner. It places emphasis on the idea that two heads are better than one.

Two things come to my mind when I think about pair programming and code reviews. First, code reviews seem to be a just-in-the-nick-of-time fix for finding bugs in code before it goes out the door. The initial development effort as already been completed and now we are evaluating the work. And realistic, this is code we’re looking at. Everyone has their opinion as how things should be structured, design philosophies, coding styles, etc. Many times code review sessions end up focusing on higher level concepts like those previously listed and not on the code itself. These kind of debates are related to decisions that should have been made prior to writing this code. Why are we asking ourselves why we did this this way now after we’ve already spent time and effort to write code for it? And the people part of the code review are not neccessarily the people that will be working with that piece of code.

That brings me to my second thought which is this is all reminiscent of Scrum pigs and chickens.


In code reviews, people sit down to review someone’s code. Everyone has an opinion but not everyone is going to be working with the code on a daily basis. At the time, everyone seems to be involved in the process but there is no vested interest. They are just looking at some code and asking themselves “does this code look good and is it correct?”. It’s a very passive standpoint. On the other hand, pair programmers are completely invested (committed?) in the task at hand. They immediately are using the code they are writing together and collobarating their thoughts on design, code layout, etc. Both programmers are taking on an active role and are emotionally invested in the task at hand because they are attacking the same problem together.

Most of the cons of pair programming can be attributed to developer social/ego issues. And they are not specific to pair programming. Going down the list of drawbacks listed on Wikipedia:

  • Developer egos: Experienced developers may find it tedious to tutor a less experienced developer in a paired environment.
  • Developer intimidation: A less experienced developer may feel intimidated pairing with a more experienced developer which may result in less participation.
  • Developer work preference: Some engineers prefer to work alone, and may find the paired environment cumbersome.
  • Tutoring cost: Experienced developers working alone may be capable of producing code that is clean and accurate at the outset, and the additional theoretical gain from pairing might not be worth the cost of an additional developer. This is especially true when producing more trivial parts of the system.
  • Potential conflict: Differences in coding style may result in conflict, and personality conflicts can result in one or both developers feeling awkward or uncomfortable.
  • Chat sessions: Sometimes employees might talk together too much, straying excessively into off-topic subjects, such as major news events, personal problems, etc.
  • Annoying personal habits: Sometimes people can find each other much more annoying when working up close than at separate workstations.

Developer egos, intimidation, work preference, and tutoring costs are things that should be checked at the door. As an experience developer, you should look for opportunities to help your fellow developers to learn and improve their skills. As a more junior developer, the opportunity to take chances and try to prove yourself is one of the best ways to learn and develop better skills. I don’t know about other people but collaborative work environments seem to be a plus. Being able to discuss your ideas openly is one of the best ways to make what you’re building better than it is. As for potential conflicts, chat sessions, and annoying personal habits, these have more to do with personalities and mannerism in the work place. All of this can happen in code reviews as well but the point is being self-aware and respectful of your coworkers is just as important as writing awesome code.

While I’m not against code reviews, I feel that pair programming is better suited to improve both code and team quality.

Pair Programming > Code Reviews

Eclipse Ganymede + Subclipse = Unable to load default SVN client???

Theo, 4 Comments

I like Shiny New Things. So when I heard Eclipse Ganymede SR1 was available, I proceeded to replace the Stream Stable Build I was currently running.

This, of course, ended up causing me problems. After installing Subclipse and attempting to pull up any SVN history, I get an error dialog box that states:
“Unable to load default SVN client”

Confused, I RTFM and saw that “Subclipse 1.4.x requires Subversion 1.5.0 version of JavaHL/SVNKit”

Seeing the SVN I was running was in fact not 1.5,

  theo@notedpath~ $ svn --version
svn, version 1.4.4 (r25188)
   compiled Nov 25 2007, 08:20:33

I went here, downloaded and installed Subversion 1.5, restarted Eclipse and things are looking good now.

Stupid shiny new things.

Eclipse Ganymede + Subclipse = Unable to load default SVN client???

Surprise your users

Theo, Leave a comment

With the launch of Chrome today, the net is all the buzz around how great Chrome is/can be. But this isn’t yet another post about chrome.

This is about me wanting to track the flight status of my parent’s airline that just came in from Cali. Of course I could go to the American Airlines website, which by the way is at aa.com, but that seemed like a lot of work when Google is my default homepage. So I thought I would just type in the flight information and hope Google would give me a direct link to the flight status page.

search

Google’s response surprised me with the following:

search-result

Wow. Thanks, Google!

Surprise your users

gem update fails – can’t find header files for ruby

Theo, 5 Comments

So, Pat got a new MacBook Pro. Little does she know, I’ve start to install programs that I would use if I just so happened to be on her computer. The laptop already had Leopard installed and all of its goodies but a bit of upgrading was called for. So, of course I had run gem update.

pats-macbook-pro:~ pat$ sudo gem update

Updating installed gems

Updating RedCloth

Building native extensions.  This could take a while...

ERROR:  While executing gem ... (Gem::Installer::ExtensionBuildError)

    ERROR: Failed to build gem native extension./System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby extconf.rb update

can't find header files for ruby.

Gem files will remain installed in /Library/Ruby/Gems/1.8/gems/RedCloth-4.0.3 for inspection.

Results logged to /Library/Ruby/Gems/1.8/gems/RedCloth-4.0.3/ext/redcloth_scan/gem_make.out

But then I ran into a strange error I had never seen before. gem update would fail when trying to build native extension. It’s been awhile since I setup a rails development environment so a-googlin’ I went.

Turns out the ruby headers don’t come installed with the base ruby install with Mac OS X. These can been found on Mac OS X Install Disc 2 by installing the XCode Tools.

Once installed, all was well!

gem update fails – can’t find header files for ruby