James Crisp

Software dev, tech, mind hacks and the occasional personal bit

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Odd Date and Time Comparisons in Rails & Hack night

While comparing Dates and Times in Rails (both 2.3 and 3), I came across an odd behaviour:

>> Time.parse("Mon, 26 Jul 2010 9:59") == Date.new(2010, 7, 26)
=> false
>> Time.parse("Mon, 26 Jul 2010 10:00") == Date.new(2010, 7, 26)
=> true
>> Time.parse("Mon, 26 Jul 2010 10:01") == Date.new(2010, 7, 26)
=> false

Also

>> Date.new(2010, 7, 26) == Time.parse("Mon, 26 Jul 2010 10:00")
=> false (Rails 2.3)
=> nil (Rails 3)
>> Date.new(2010, 7, 26) == Time.parse("Mon, 26 Jul 2010 0:00")
=> false (Rails 2.3)
=> nil (Rails 3)

Tonight, we’ll be having the RORO hack night in the ThoughtWorks Sydney office, with a focus on open source projects (your own or contributing). A patch for this date/time behaviour might be an interesting area to pursue.

Ruby 1.8 Scoping and Blocks

Quick ruby quiz.. after these two lines execute, what is the value of number?

>> number = 5
>> (1..10).each {|number| print number}

Well, number will be 10, thanks to the block being run and re-assigning the value of number. This can cause you some pretty subtle bugs if you happen to have the same name for a local/function argument, and as a variable name in a block.

In C#, the compiler is kind enough to tell you that this would be a very bad idea and give you an error.

And thanks to Sudhinda for commenting – this has been fixed in Ruby 1.9. In 1.9, the variable used as the argument in the block does not affect the variable outside the block.

Showing Hidden Files in Mac Finder

If you’ve been longing for your Mac finder to show all the files on disk, then this command is for you. Run on the console:

defaults write com.apple.finder AppleShowAllFiles TRUE
killall Finder
Now you’ll be able to see all the .config files in your home directory and all the normal Unix directories on the root.

Azure Build and Deploy using Powershell

Started working with Windows Azure? Want to have automated build and deploy, rather than clicking around in a web console or Visual Studio?

Check out the AzureBuildDeploy repository on GitHub.

I set this up for an Azure proof of concept project. It contains Powershell scripts for simple automated packaging, build and deploy, and a dummy WCF application for deployment to the cloud. The WCF application can however be easily replaced with a web application or what ever other .NET application you would like to host in the cloud.

How to use

  • Clone or download the source from http://github.com/jcrisp/AzureBuildDeploy
  • Update the $serviceName at the top of build-package-deploy.ps1
  • Update the certificate details, and subscription id at the top of deploy.ps1
  • If you plan to use SqlAzure (as in my proof of concept), update the connection details in HelloWorldService.svc.cs. If you don’t plan to use SqlAzure, just stub out the whole FindFirstGreetingUsingSqlAzure() method by returning a string.
  • Test out deployment to the cloud (run build-package-deploy.ps1). You can ensure it is working using the sample client in the repository.
  • Now you’ve got everything working, replace the dummy WCF application with whatever you want.

Notes
In my experience, the deployment of a simple application via these scripts, Visual Studio or the console takes about 16 minutes, from start of deploy to the service able to accept clients. This is extremely slow – I hope it improves!

Workaround for Subversion (SVN) certificate verification error: insecure algorithm on Ubuntu 10.04 Lucid Lynx

If you try to check out your code from a hosted subversion repository, under your shiny new Ubuntu 10.04, you may be disappointed to have it fail with the error:

svn: OPTIONS of 'https://server.com/repo': Certificate verification error: signed using insecure algorithm (https://server.com/repo)

Despite multiple threads on various linux and subversion forums which didn’t really help (it’s not subversion’s fault, it’s from gnu-utils, and yes, it would be great if everyone could get all their hosting providers to upgrade their certificates, and you could patch and recompile relevant utils), I finally found a work around here in Slovak. With a bit of help from Google translate, here is the work around:

Add to the end of your ~/.subversion/servers file:
ssl-trust-default-ca = no

It means you’ll have to verify every certificate manually, but at least you’ll be able to check out your code until you can get your hosting provider to update their certificates! Happy days!

ACS Alm Talk: Presentation Wrap Up & Slides

Thanks everyone who came along last night. It was a fun session, with a lot of lively discussion, especially around project management and software design. As mentioned during the talk, you might want to check out nRake for .NET builds and psDeploy for Powershell deployments. Here are the slides from the talk. If you have any more questions or areas to discuss, please feel free to drop me a line.

ACS Talk: The Ultimate ALM Environment (circa 2010)

I’ll be giving a presentation at an Australian Computer Society Special Interest Group on Wed 2 June, 6:30pm. More details here.

The abstract is:

Application Lifecycle Management (ALM) covers the whole software development lifecycle and associated processes including project management, business analysis, testing, build and deploy and development. Based on experiences in the field on projects with ThoughtWorks and consulting with other teams, I will describe what I consider to be the ultimate ALM environment, using an agile approach and techniques. This talk will cover goals, assessment criteria, practices, tools, and physical workspace design.

Hope to see you there!

Multi-touch two finger scrolling on Samung N150 with Ubuntu 10.04 (Lucid Lynx)

After much googling, trial and error, finally, a solution for enabling two finger scrolling on Ubuntu 10.04 on my new Samsung n150 netbook.

For some reason, it is not possible to enable it through the Mouse configuration in GNOME – the two finger scrolling option is grayed out (disabled).

You may need to fine tune the MinW and MinZ values – they are configured to work well for my fingers 🙂

synclient VertTwoFingerScroll=1
synclient HorizTwoFingerScroll=1
synclient EmulateTwoFingerMinW=5
synclient EmulateTwoFingerMinZ=48

To make these settings sticky, add the synclient calls into a script that runs when you log in.

nRake now on IronRuby

nRake, the premier project and build template for .NET projects using the Rake build system now has a branch for .NET4 using IronRuby. Projects are also updated to VS2010 format, and Albacore gems are now updated to 0.1.5.

Check out the IronRuby .NET 4 branch of nRake.

or the check out the IronRuby .NET 2 / 3.5 branch of nRake.

Master branch is still using MRI ruby 1.9. However, plans are to change over to IronRuby for master branch in the future. IronRuby is now performing well enough and sufficiently compatible to support .NET builds. IronRuby has advantages around size (smaller download) and more exciting interop possibilities with .NET code.

Podcast from ALM Conference

At the ALM Conference, Richard interviewed me for a podcast on the Ultimate ALM Environment circa 2010 as well as a little on build and deployment automation. Check out the podcast on Talking Shop!

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