Registration & Call for Papers Open for JUC Palo Alto

This year, the West Coast Jenkins User Conference will be in Palo Alto rather than San Francisco. If you’re nearby – or even if you’re not – join Kohsuke and other fellow developers for a solid day of Jenkins.

The Call for Papers is open until June 9 (scroll to bottom of page for form).

Report: Intro to Jenkins meet-up in Copenhagen

We have hosted two informal meetups introducing Jenkins Continuous Integration Server.

The first in end of June (announced here on this blog) and the second on the 7th of August. The first meet-up in June was only announced 8 days before, but had very good attendance - the second was completely booked (15 seats).

The agenda is a short presentation of continuous integration and software validation to inspire the use of Jenkins, then a few words and terms about Jenkins and finally a live demo. The live demo starts from scratch by downloaded the latest Jenkins java web archive, starts it, define a job on one of our Maven based java projects on Github. We add two easy plugins (Warnings and Task Scanner). Second part of the demo is about unit testing and coverage and we show how easy it is to enable a JUnit report and add a Cobertura coverage report if there is already unit tests for the project.

The meetups have about 90 minutes scheduled, including questions and the discussion session after the demo, where we serve pizza, beer and cola. The theoretical presentation and live demo is typically finished within one hour, even though we encourage our guests to ask questions and discuss whatever comes into their mind on the way. The relatively short time used for the introduction demonstrates how easy it is to get started with continuous integration and software validation using Jenkins.

As the live demo is based on a Java/Maven project we ask the guests about their technologies and try to relate that to their setup, so they know there also is an easy approach for them to use Jenkins.

The meeting is quite informal, and limited to 15 participants, leaving plenty of time to dicsuss and answer questions both before and after the meeting. We are always a few developers from Praqma to facilitate the discussions about the participants individual setup and questions.

These informal discussions are one of the main gains for us in Praqma, as it is very interesting to share our experience with our guests and hear about all of their interesting challenges, that might have brough them north of Copenhagento attend our meeting.

Because these first meet-ups have been so popular and interesting we have decided to arrange them regularly in the future. Not just the Jenkins introduction, which will be repeated as long as there is an interest, but we are also making plans for meetups about Git, Mercurial and other topics.

If you're interested in more Jenkins and CI related meet-ups in the Copenhagen area, visit our homepage or follow the #pragma hashtag on Twitter.

We also have a Jenkins User Event in Copenhagen coming in September.

Why does Jenkins have blue balls?

A japanese traffic light It is interesting having an open source project that is sufficiently old to start generating "lore" of some form or another. Jenkins is starting to get to be that age, having been started over 6 years ago.

One of the most commonly asked questions, is about Jenkins' use of "blue balls" to indicate success by default. This is enough of an "issue" for some users that the Green Balls plugin is in the list of top 10 installed plugins.

The reason behind our use of blue to indicate success has its basis in Kohsuke's Japanese upbringing. The cultural differences were enumerated in a bug report comically titled "s/blue/green/g" (JENKINS-369):

This response Kohsuke cited was taken from this Q&A thread

Q. "Why do Japanese people say that they have blue traffic lights when they are really green?" --Question submitted by John Sypal

A: According to the book, Japan From A to Z: Mysteries of Everyday Life Explained by James and Michiko Vardaman, the first traffic signals in Japan were blue instead of green, but the blue lights were difficult to see from a long distance away so they were replaced with green ones. Vardaman says that the custom of referring to traffic lights is a holdover from those days.

This sounds like a good explanation, but the problem with it is that you will hear Japanese people refer to other green things (like cucumbers, spinach, and sometimes grass) as being blue as well. This is because historically, Japanese people considered green to be a shade of blue. For example, the Chinese character for blue, pronounced ao is made up of two characters, iki (life) and i (well) and refers to the colour of plants which grow around a well, a colour between green and blue. When Chinese people see the character, they say it means green, but Japanese people say it means blue.

Japanese books on colours tell us that there are four tertiary colours: red, blue, white and black, and that all others are shades of those four main ones. Ao, therefore, is a sort of ideal blue, halfway between green and blue. The sky is said to be blue, but it is a different shade of ao than a traffic light is. Tree leaves are said to be green, but green is a shade of ao, like crimson is a shade of red.

In another interesting cultural difference relating to colour, Japanese children always colour the sun red instead of yellow.

(here's a direct link to Kohsuke's comment)

Unfortunately it's not for color blind users, although that's a pretty convincing explanation. Jenkins has blue balls because in Japan, red means stop and blue means go!

Building Jenkins plugins with Gradle

Until now, Jenkins plugins written in Java or Groovy could only be built with Maven, using the maven-hpi-plugin to generate a proper manifest and archive which Jenkins can consume. But starting now, you can also use Gradle!

See the wiki for information on how you can use Gradle and the new gradle-jpi-plugin to build, test and release your Java or Groovy Jenkins plugin.

Holiday appeal: please help Jenkins pay the project expense

As we approach the holiday season, which is when people start to feel more charitable, at least in the U.S. So I'd like to make one more plea, that the Jenkins project needs your help in paying its expense, and that we are still about $1000 shy of the goal we need to get to. So if you can, please help us by donating to Jenkins via SPI.

Think about all the benefits you are getting from your Jenkins, and think about all the volunteer efforts that went into it. Some help by writing code, some help by answering other users questions, and some help by spreading words about Jenkins. If you've been wanting to contribute to the project but you haven't figured out how, this is one way to do it.

As a thank you, I'm writing a special "friend of Jenkins" plugin that I'd like to send out to those who have donated, so that you can show off your support on your Jenkins instance.

Once again, please help us reach our fundraising goal.