Eirik's public note to self

How to trigger a build in Jenkins for each commit in Mercurial

2011-12-01T17:08:00.001+01:00

Just add the following to the hgrc file in the project's hg directory:

[hooks]
commit.jenkins = java -jar <path to jenkins-cli.jar> -s http://<Jenkins URL>/ build -c <project name>

To get the jenkins-cli.jar file, follow the instructions in this post.

More information on Mercurial hooks can be found in Mercurial: The Definitive Guide.

How to trigger a Jenkins build from command-line

2011-12-01T17:00:00.001+01:00

To trigger a Jenkins build from command-line is pretty simple. In *nix, you can use wget to trigger the build via a HTTP request. If you don't have that kind of tool available on your platform (e.g. Windows), the CLI-client is a useful option.

First you need to download the client jar file; you can get this from http://<your Jenkins server>/cli. Place the jar file in an accessible location.

To start the build, just issue the command:

java -jar jenkins-cli.jar -s http://<your Jenkins server>/ build <project name>

GlassFish v3: Picky about where the libraries in an EAR are located

2011-09-04T04:09:00.001+02:00

While trying to deploy an EAR-application on GlassFish v3, I got an error about missing class files. The mentioned class files where from external libraries packaged along with my EJB inside the ear-file. I found this strange since the same ear-file deployed just fine on GlassFish v2. Strange...

After a couple of hours with trial-and-error and my favorite troubleshooter (Google), I came across another guy who had similar problems. It turned out that GlassFish v3 is more picky about where libraries are located. The short answer: Just add a simple line in the pom.xml:

<library-directory>lib</library-directory>

killall in Windows

2011-09-04T03:59:00.000+02:00

Recently I ran into a serious annoyance while using a Windows computer at work. Something triggered a cascade of processes that crashed and spawned other Dr Watson-threads. This bugged down my computer enough to be pain in the ass, and I didn't want to use the reset button on my computer, so I opened the Task Manager and looked for something that resembled killall from Unix. No such luck.

Once more Google provided me with a solution. How-to Geek had written an article about the taskkill utility in Windows:

taskkill /F /IM <processname.exe> /T

How to use a global ignore file in Mercurial

2011-09-04T03:48:00.000+02:00

I got tired of manually adding common elements to the .hgignore-file, so after some quick research the option for a global ignore file presented itself as the solution to my problem.

Just a few lines in the Mercurial user file is needed:

[ui]
ignore = C:\<some path>\mercurial.ignore

Example content for the ignore-file:

target

This information is also available in the user manual.

Web harvesting and GUI testing with WebDriver

2011-07-08T22:57:00.001+02:00

For a spare time project I've been working on lately, I had to web harvest (also known as screen scraping) a couple of web pages to get the information I needed. A coworker recommended WebDriver, a part of Selenium testing framework.

In a nutshell, WebDriver is a library that controls your browser from code. This can be useful when doing GUI testing or when you want to simulate a web browser to fetch something from the web.

You can control different browsers (Firefox, Chrome, etc). In my experiment I used Firefox. WebDriver currently only support version 3 of Firefox, so I had to download it and point WebDriver to where it was located.

WebDriver worked very well for my project and even though I'm not a big fan of web harvesting the overall result was good enough.

How I pointed WebDriver to Firefox 3 and turned on autodownload for Excel spreadsheets:

        System.setProperty("webdriver.firefox.bin", "/opt/firefox-3.6/firefox/firefox");
        FirefoxProfile fp = new FirefoxProfile();
        fp.setPreference("browser.download.dir", "/tmp/firefox-webdriver");
        fp.setPreference("browser.download.folderList", 2);
        fp.setPreference("browser.helperApps.neverAsk.saveToDisk", "application/mx-msdownload");

        WebDriver driver = new FirefoxDriver(fp);

The Maven dependency looks like this:

        <dependency>
            <groupId>org.seleniumhq.webdriver</groupId>
            <artifactId>webdriver-firefox</artifactId>
            <version>0.9.7376</version>
        </dependency>

My list of recomended reading for software developers

2011-07-05T01:52:00.000+02:00

Here is a list of books and online resources that I would recommend to fellow developers.

General books

The Pragmatic Programmer: From Journeyman to Master by Andrew Hunt and David Thomas
Code Complete: A Practical Handbook of Software Construction by Steve McConnell
Peopleware: Productive Projects and Teams by Tom DeMarco and Timothy Lister
Facts and Fallacies of Software Engineering by Robert L. Glass

Java books

Effective Java (2nd Edition) by Joshua Bloch

How to install Ubuntu 11.04 in VirtualBox

2011-07-03T20:51:00.000+02:00

I wanted to have a clean environment where I could try different things and decided to install VirtualBox on my desktop.

To install the host software under Ubuntu was easy. Just a simple apt-get command:

sudo apt-get install virtualbox-ose

The installation of the guest OS was easy enough, just point and click. But when I tried to install the guest additions (so that the guest OS could access folders on the host) the guest OS would not boot up again. This happened a few times and the result was reinstall the guest OS. Next time I will remember to take a snapshot just after the install finishes.

After a simple google search, I found a blog entry on how to install the guest additions via apt-get:

sudo apt-get update
sudo apt-get install virtualbox-ose-guest-utils

How to change default browser on Samsung Galaxy Tab

2011-07-02T19:46:00.001+02:00

I wanted to change the default browser on my Galaxy Tab to Firefox, but couldn't find a setting for it (in an intuitive way). So after some googling and trial and error, I found what I was looking for.

The solution: Programs -> Settings -> Applications -> Administer programs -> All -> Select the current default browser -> Clear standard

Note: The user interface on my tablet is in norwegian, so I had to translate the menu items into english. I think the translations should be close enough to get others on the right track.