Jenkins “ghost” slaves

I use Jenkins a lot at work. We have quite an expansive setup; tens of agents and hundreds of jobs. We run specific jobs on specific agents based on labels. For a while we had some labels show up on our Labels Dashboard that we’re listed as having no Jobs, but one slave; a “ghost” slave. However when going into the page of the specific label the agent/slave was not showing anything. 

After some investigating with some Groovy script through the console I found there exists a slave in the configuration without a computer. To remove it (and resolve my label issues) I ran the following script:


for (slave in Jenkins.instance.slaves) {
  if (slave.getComputer() == null) {
    println(slave)
    Computer computer = slave.createComputer();
    computer.setTemporarilyOffline(true,null);
    computer.doDoDelete();
  }
}

Things I Mean to Know

I regularly listen to podcasts in the car. One of the podcasts I follow is This American Life. Sometime ago they put out an episode titled “Things I Mean to Know“. This triggered me into creating a list for myself. Not necessarily to blog about it, but to have a grand feeling of what technologies I can say I do know something about and what not.

Funnily the podcast goes into quite the opposite opinion; that such lists are just a burden. During my work I regularly speak to customers, partners and other technical people. Usually new technologies come up and I want to be able to have at least a general idea what it is about!

So here a broad list of Things I Mean to know; mostly pulled from Gartner. (story behind)

  • Data science and big data
  • Quantum computing
  • Digital twin
  • Serverless, edge computing and IoT platforms
  • Volumetric displays (Holograms)
  • Deep learning, machine learning

This post is a reminder for myself to report back to you, my readers, about what I’ve learned and to explain what is worth diving into or what can be ignored.

In another future post I will dive into things I’ve already digged into last year (2017) and that I’m currently experimenting with; Things I’ve Learned About.

Quick FBX Inspector

This week I came across a simple option to inspect FBX files, something I’ve always wanted to have. It’s not a native solution or does not have fancy GUI or has a 3D viewer. It’s a framework to use the FBX SDK using .NET. The sample that comes with it, does just what I need!

At Soltegro we’re working with BIM models in the form of Revit, Navisworks or AutoCAD files. Each of these pieces of software can transform these files into FBX files, however they all do it differently. And to that end I’m looking for a way to inspect the FBX files, and it’s internal tree, before importing them into Unreal Engine 4.

You can find the tool on GitHub; https://github.com/Kolky/ManagedFBX. Thanks to returnString for the first version. 

I’ve modified it slightly to support the FBX SDK 2016 v1.1 used by Unreal Engine 4.16. And made it support FbxProperties and expanded the sample to be more versatile. I might add a WPF version of the Sample and also more FBX info in the future. But for now it does what I need!

Managed FBX Sample

AnyStatus ‘support for Jenkins MultiBranch’

Two weeks ago I came across a plugin for Visual Studio; AnyStatus. It gives you the ability to keep track of all kinds of services/servers while working in Visual Studio. It lacked the ability to track Jenkins MultiBranch projects, what we use a lot at my work; Soltegro. Since the API was straightforward and freely available in GitHub, I decided to develop it myself. And as of this week it has been merged into the Plugins dll; Pull Request 4.

The code could use some extra work, when the API introduces a better way for managing and creating sub-items. There is still discussions going on about this; Issue 2.

Jenkins ‘Build back to normal’

Yesterday, I finished porting our Jenkinsfile to use the new Declarative syntax. It makes the flow of processing a lot more straightforward and it’s great for handling errors and post actions. However getting everything to work again was tricky!

I was looking to send an e-mail and Office365 notification when a build returns to normal. Others updated the status of the current build during their steps, as seen on stackoverflow and here. I managed to do it slightly different without having to manage the current state;

pipeline {
  agent any
  post {
    success {
      script {
        if (currentBuild.getPreviousBuild().getResult().toString() != "SUCCESS") {
          echo 'Build is back to normal!'
        }
      }
    }
  }
}

For more details on the syntax of declarative pipelines, I’d recommend this site.