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Amazon S3 allows you to set per-file permissions to grant read and/or write access. This is nice, but sometimes you just want to share your whole bucket with the world. Luckily, Amazon features bucket policies, which allow you to define permissions for an entire bucket. ~ This example will give read access to Everyone on all files in your bucket. 1{ 2 "Version":"2008-10-17", 3 "Statement":[{ 4 "Si

[Today I learned][1] that Ruby garbage collection can be of huge importance to performance. More precisely, if Ruby does a lot of garbage collection it may slow down your code. Running garbage collection only every 10 or 20 seconds when running specs may increase performance dramatically. At this time specs for Ariejan.net take an average of 25.29s to run. This is not bad, but in my opinion faster

Exceptions happen. There’s no way around that. But not all exceptions are created equally. For instance, a 404 “Not found” error can (and should) be handled correctly in your application. Let me give you an example of how to handle a ActiveRecord::RecordNotFound exception. Let’s assume you have an application that could show a user profile: 1# GET /p/:name 2def show 3 @profile = Profile.find(param

I literally always have to look up the meaning of :limit in migrations when it comes to integer values. Here’s an overview. Now let’s memorise it (oh, this works for MySQL, other databases may work differently):

Lighting fast, zero-downtime deployments with git, capistrano, nginx and Unicorn Everyone who has ever developed a web app has had to deploy it. Back in the day you simply uploaded your files with FTP and everything would be good. Today we have to clone git repositories, restart servers, set permissions, create symlinks to our configuration files, clean out caches and what not. Doctor, what’s wron

Today I found about 100k Resque jobs in the failed queue. Due to a small error in some user content, those jobs all failed. After fixing the problem, how do you reprocess all those jobs? Option one: go to the resque-web backend and click retry about 100.000 times. Option two: do some cool ruby commands. ~ Resque offers you direct access to the failed queue and also provides a method to requeue job

In this example I’ll show you how easy it is to sort an array of (the same kind of) objects by an attribute. Let’s say you have an array of User objects that have the attributes ’name’ and ’login_count’. First, find all users. 1@users = User.find(:all) Now, we have to sort this array by ’name’. Since we don’t know if any user used capitals in his name or not, we use ‘downcase’ to sort without case

Creating a patch file with git is quite easy to do, you just need to see how it’s done a few times. This article will show you how to create a patch from the last few commits in your repository. Next, I’ll also show you how you can correctly apply this patch to another repository. Before you start To make creating patches easier, there are some common git practices you should follow. It’s not nece

Sometimes, using the good old ‘auto increment’ from your database just isn’t good enough. If you really require that all your objects have unique ID, even across systems and different databases there’s only one way go: UUID or Universally Unique IDentifier. A UUID is generated in such a way that every generated UUID in the world is unique. For example: 12f186e6-687e-11ad-843e-001b632783f1. This st

I’m currently writing some RSpec tests that use Time.now. I want my model to calculate a duration and store the future time in the database. I’ve already specced the calculation of the duration, but I also want to spec that everything gets saved correctly. Here’s my first spec: 1it "should do stuff" do 2 m = Model.create() 3 m.expires_at.should eql(Time.now + some_value) 4end This fails. It fails

BaseApp is no longer maintained. There is a very good alternative called bort. For the impatient: http://github.com/ariejan/baseapp Got issues? Feature requests or patches? http://baseapp.lighthouseapp.com/ Every Rails developer has at least once developed an application that needed user authentication and some basic UI features like tabs and a sidebar. Ask yourself now: “how often have you instal

I’ve talked before on how to use ActiveScaffold with acts_as_taggable_on_steroids. The problem with that solution was that, although the checkboxes for every tag are very nice, you couldn’t easily add new tags. For some people, this may be fine, for others, it is not. Together with a colleague (who wishes not to be named), I found a solution that is quite elegant. Instead of using check boxes, and