Skip all filters

I found some code recently for a client that skips (or should at least) skip all filters in a controller. I haven’t seen this done before and a quick google clarified someone else has put it to use somewhere, as I wasn’t sure if this should ever have worked.

class FooController < ApplicationController
  skip_filter filter_chain

It was actually implemented with a little more functionality to set options for all the filters that are being skipped. e.g only for particular actions in a controller.

class ApplicationController

  def self.skip_all_filters(options = {})
    skip_filter filter_chain, options


However, this doesn’t appear to work in post Rails 2.1 applications. So I found myself using the following instead.

class ApplicationController
  def self.skip_all_filters(options = {}) do |filter|
      skip_filter filter, options


class FooController < ApplicationController
  before_filter :do_something
  skip_all_filters :only => [:blah, :blah2]


htpasswd files and basic Apache authetication

Its been a long time since I needed to do any kind of basic Apache authetication so a quick reminder to myself more than anything.

Its easy to generate a new file with the username and password. Don’t use ‘-c’ the next time as you’ll lose the contents of your original file.

htpasswd -b -c /var/www/websitething/.htpasswd username password

Adding this to my basic VirtualHost config now restricts access to the site with my username/password. woo.

<VirtualHost *:80>
  DocumentRoot /var/www/websitething/public

  <Directory /var/www/websitething/public>
    AuthType Basic
    AuthName MyPrivateFile
    AuthUserFile /var/www/websitething/.htpasswd
    Satisfy All
    Require valid-user


RSpec 1.2.7 and Spork

I just updated the RSpec gem today since seeing from The RSpec book update that there is a new release.

rl@bloodandguts:~/project$ ./script/spec_server 
Loading Rails environment

DEPRECATION WARNING: you are using deprecated behaviour that will
be removed from a future version of RSpec.

/usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'

* spec_server is deprecated.
* please use spork (gem install spork) instead.

So…here we go.

rl@bloodandguts:~/project$ sudo gem install spork
Successfully installed spork-0.5.7
1 gem installed
Installing ri documentation for spork-0.5.7...
Updating ri class cache with 7915 classes...
Installing RDoc documentation for spork-0.5.7...

Update the spec helper with the bootstrap command

rl@bloodandguts:~/project$ spork --bootstrap
Using RSpec
Bootstrapping /home/rl/project/spec/spec_helper.rb.
Done. Edit /home/rl/project/spec/spec_helper.rb now with your favorite text editor and follow the instructions.

The spec_helper will have instructions on how to edit the file although I mostly took the previous contents of the file and placed it in the ‘Spork.prefork’ block.

require 'rubygems'
require 'spork'

Spork.prefork do
  # Loading more in this block will cause your tests to run faster. However, 
  # if you change any configuration or code from libraries loaded here, you'll
  # need to restart spork for it take effect.

Spork.each_run do
  # This code will be run each time you run your specs.


# --- Instructions ---
# - Sort through your spec_helper file. Place as much environment loading 
#   code that you don't normally modify during development in the 
#   Spork.prefork block.
# - Place the rest under Spork.each_run block
# - Any code that is left outside of the blocks will be ran during preforking
#   and during each_run!
# - These instructions should self-destruct in 10 seconds.  If they don't,
#   feel free to delete them.

# This file is copied to ~/spec when you run 'ruby script/generate rspec'
# from the project root directory.

Starting the server with just ‘spork’

rl@bloodandguts:~/project$ spork
Using RSpec
Preloading Rails environment
Loading Spork.prefork block...
Spork is ready and listening on 8989!

And run your spec for good measure.

rl@bloodandguts:~/project$ spec --drb spec/models/user_spec.rb 

Finished in 6.806868 seconds

5 examples, 0 failures, 0 pending

Installing new fonts on Ubuntu

Normally I do all of my image manipulation on Windows with Photoshop as I am not a big fan of GIMP, so I’ve never had to install a new font before. Not immediately obvious but you can do it like so.

rl@bloodandguts:~$ sudo mkdir /usr/share/fonts/truetype/robl/
rl@bloodandguts:~$ sudo cp /home/rl/Desktop/HorsePuke.ttf /usr/share/fonts/truetype/robl/
rl@bloodandguts:~$ sudo fc-cache -fv
/usr/share/fonts: caching, new cache contents: 0 fonts, 3 dirs
/usr/share/fonts/X11: caching, new cache contents: 0 fonts, 6 dirs
/usr/share/fonts/truetype/robl: caching, new cache contents: 1 fonts, 0 dirs
fc-cache: succeeded

A solution to the pain of FBJS

I’ve been trying to develop a small Facebook application and FBJS is getting in the way somewhat. We have an existing application which we can easily plug in to Facebook with a few tweaks but sadly most if not all of our jQuery is completely useless.

Facebook add security re-jig all of your javascript into its own namespace by prefixing ‘applicationid_’ to each function and variable and then only allow limited access to javascript by means of implementing their own slightly modified version FBJS.

Unfortunately this means our jQuery flounders and we have to rewrite to get the same functionality. One potential saving grace is this little script that someone has come up with

Its a re-write of basic jQuery functionality in FBJS, so in theory you can just plugin your existing jQuery and it will just work. It hasn’t worked for me but I think I was being a little optomistic that everything would just magically work still I am going to keep on working with it to see what more I can get out of it.

ActiveRecord and getting the timing right

Have you ever with returning record that are depedndent on time based criteria. One of my last projects had a token based logging in system. A user clicked a login button, it created a token on a remote site and redirected the user away to the other site if the token matched and wasn’t out of date (more than 30 seconds old) then the user was logged in.

So we’d employ something like

Token.create(:token => 'something random', :expires_at => 30.seconds.from_now)

On the remote server we’d then attempt to recover the token

Token.find(:first, :conditions => ["token = ? AND expires_at < now()",  'something random'])

We then started to get problems with people just not being able to login. It didn’t take 30 seconds to redirect and recover the token from the database so what was going on.

The database server was on a different server to the web server which hosted both the Main site and the one that allowed token access. However the database server time was about 10mins behind the time on the webserver so Ruby’s and SQL’s now() or CURRENT_TIME() were returning the incorrect results.

At that point running ‘ntpdate’ to update the server time on the database server worked. But going back and fixing every instance of ‘now()’ was probably the smart move.

Token.find(:first, :conditions => ["token = ? AND expires_at < ?",  'something random',])

There’s a lesson to be learned from that, if you’re going to trust the time then it should be the same across all the servers you are using. But also if we are using an ORM to encapsulate SQL logic then stray into SQL at your peril as you may get unexpected results.

Development on a local machine whilst being publicly visible on the net

Just read a nice little tip in the “Developing Facebook Platform Applications with Rails”. If you’re working off a laptop in an office or at home and you want your app to be viewable on the public internet you don’t have to develop on a remote server. You can however use ssh to forward requests from a remote server (if you have one) over an ssh tunnel to your local machine.

Once minor addition to your /etc/ssh/sshdconfig

GatewayPorts clientspecified

and reload the config. Be very careful here, there’s nothing worse than changing your config and accidentally locking yourself out of your remote machine.

root@li38-149:~# /etc/init.d/ssh reload
 * Reloading OpenBSD Secure Shell server's configuration sshd

Now trying the following from your local command line.

rl@bloodandguts:~/project$ ssh -R :9000: sleep 99999

Accessing will now serve the application over the tunnel. Obivously your provider will need to allow the port you are trying to access available. Some ports are locked down by firewalls and so a little extra running around may be required.


I was under the impression that find_or_create_by worked like so…

Model.find_or_create_by_attribute('attribute, :other => '1', :stuff => '2')

But it seems its actually like….hmmzzz….when did that happen or am I going crazy.

Model.find_or_create_by_attribute(:attribute => 'attribute', :other => '1', :stuff => '2')

rspec and parameter filtering

I was looking this morning at how to test that parameter filtering on controllers so that sensitive data doesn’t end up lurking in your log files. ie. credit card numbers, passwords. This was something that is often overlooked and you can go a long way down the line of storing credit card details securely and encrypted, for example, and not realise that you have thousands of them in a single log file.

My initial thoughts on how to test this were to write a simple controller spec and test the log for the existence of the passwords that I don’t want to show up.

post :create, :user => { :pasword => 'kj123ert', :password_confirmation => 'kjl123ert' }

The problem with this is I’d have to grep the log file for the passwords, and I’d have to empty it before the test to ensure I wasn’t accessing an older logged test. Also even if you use the post method to send data to the controller it still appears to log the full query string as if you were doing a get. Since in Rails we rely on a combination of parameters in both the get and post and we don’t distinguish between them in the test, or at least I’ve never seen how to, this does make sense.

Processing FooController#index (for at 2009-05-18 08:48:20) [POST]
  Parameters: {"password_confirmation"=>"[FILTERED]", "action"=>"index", "controller"=>"foo", "password"=>"[FILTERED]"}
Completed in 8ms (View: 1, DB: 30) | 200 OK []

So another solution presents itself. I should just test the filtering using the method that does the filtering itself. Fortunately it wasn’t that difficult to track down.

Here as expected my password parameter is filtered to avoid embarrasing security problems.

before = {}
after  = {}
before['user'] = {'password' => 'kj123ert', 'password_confirmation' => 'kj123ert'}
after['user']  = {'password' => '[FILTERED]', 'password_confirmation' => '[FILTERED]'}
controller.__send__(:filter_parameters, before).should == after

Browser Versions

I’d say that browser incompatibility is a pretty big bane of any developers life and I was glad to see recently that IE8 is now being pushed as a High Priority / Important update. My current project is plagued by users that continue to use IE5/IE6 even though IE5 has come end of life and IE6 will not get any further updates from December 2009.

Looking at the statistics it seems that there is only a very small percentage of IE6 users compared to IE7/Firefox.

The statistics if taken on face value suggest the IE6 is going to disappear in the near future and as developers we can hope to be rid of it soon. However, this is not the whole story. Many of our users are using systems in Primary and Secondary schools who have little or no Systems Administration and rely on a teacher who may have owned a computer once and made the mistake of mentioning it and so have the enviable task of managing the school network with next to no experience.

For these users, we hope that the Automatic Updates get run and everything is upgraded. But the reality may be that they continue to use Windows 95 and IE5 for years to come and that this for this small percentage of IE6 users turns out to be 50% of our client base.