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Integrating Jenkins, SonarQube, and Nexus

Mon, 24 Feb 2014 00:25:00 +0100

In this post I will describe a solution to add a portal page, a common header and a dynamic panel to each of the three tools Jenkins, SonarQube, and Nexus. Those modifications lead to a better visual integration and intensifies the impression that the tools belong together.

As a pre-requisite you need an Apache HTTP server, configured as reverse proxy and the tools accessible via the following context path:

/jenkins
/sonarqube
/nexus

The folder structure which contains the portal page and the customization fragments looks like this:

Page decoration plugins for Jenkins, SonarQube, and Nexus

Sun, 23 Feb 2014 18:34:00 +0100

While trying to apply a unified visual layout to the tools Jenkins, SonarQube, and Nexus I learned that there are some plugins available, but none of them really fits the intended purpose.

Jenkins has no easy way of changing its appearance and the Simple Theme plugin comes only close to what is needed. In SonarQube there is a Branding plugin with which you can display an image at the top of each page, but that’s basically all. The Nexus plugin to change the Sonatype Nexus logo is available for the professional version only, but buying the professional version just for being able to change the logo is not really an option.

Music Player Daemon on Raspberry Pi

Mon, 10 Jun 2013 21:06:00 +0200

This is not yet another “how to configure MPD on the Raspberry Pi” article, because there are a lot of excellent MPD HOWTOs already available:

However, I experienced a bottleneck with the configuration described by those articles. The load was slightly over 1 but it was high enough to cause some stuttering every 30 seconds.

The first optimization is to avoid using a separate streaming solution like icecast

MPD has its own, built-in streaming plugin which can be configured like this:

Debugging UPnP/DLNA traffic to a Sony LCD TV

Mon, 08 Oct 2012 14:27:00 +0200

The issue I have is that my Sony LCD TV seems to be very picky regarding the UPnP/DLNA protocol when playing media from a control point to the television. The Android App BubbleUPnP does a good job here as playing music works out of the box. Initial tests with the Cling Java library to play music does not work out of the box. Therefore I wanted to debug the HTTP SOAP protocol in order to see where the differences are.

Use Java 7 on Buildhive

Tue, 14 Aug 2012 14:09:00 +0200

Changing source and target version to 1.7 is not sufficient to enable Java 7 on Buildhive at the moment.
Adding the following profile to your Maven POM makes sure that your local build is not affected by the special configuration and when running on Buildhive, JDK 7 is used for both build and test-run.

  <profiles>
    <profile>
      <id>buildhive</id>
      <build>
        <plugins>
          <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>2.5.1</version>
            <configuration>
              <source>1.7</source>
              <target>1.7</target>
              <showDeprecation>true</showDeprecation>
              <showWarnings>true</showWarnings>
              <encoding>UTF-8</encoding>
              <executable>/opt/jdk/jdk1.7.0/bin/javac</executable>
              <fork>true</fork>
            </configuration>
          </plugin>
          <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
            <configuration>
              <jvm>/opt/jdk/jdk1.7.0/bin/java</jvm>
              <forkMode>once</forkMode>
            </configuration>
          </plugin>
        </plugins>
      </build>
    </profile>
  </profiles>

The profile can be selected by adding the following line to the configuration of your Buildhive job:

Raspberry Pi

Sat, 30 Jun 2012 12:26:00 +0200

My Raspberry Pi finally arrived after 4 months:

The stable Debian distribution “Squeeze” does not contain support for all of the Raspberry Pi features. That means there is no way around the the latest Debian “Wheezy” image: http://www.raspberrypi.org/archives/1435

But even with the latest image version there is still some configuration effort left…

WLAN Stick

For network connectivity I have chosen the Conrad WLAN Stick N150 Nano, which is based on the following chipset: USB: 0BDA:8176 Realtek Semiconductor Corp. RTL8188CUS 802.11n WLAN Adapter.
Unfortunately this chipset has some issues with the current drivers from both Debian Linux images as discussed in the forum thread Automatic setup for RTL8188CUS based wifi adapters. By executing the script install-rtl8188cus-latest.sh from the forum thread, the adapter started working immediately after the script was finished.
The general WLAN configuration is described in detail in the Debian Wiki: http://wiki.debian.org/WiFi/HowToUse#Command_Line

Wake On LAN

Sat, 03 Mar 2012 22:50:00 +0100

Under Ubuntu I chose the following way to activate wake on LAN on the eth0 device:

# Install ethtool
sudo apt-get install ethtool
# Create init script to set the wol bit on the device
sudo vi /etc/init.d/wakeonlan
#!/bin/sh
ethtool -s eth0 wol g
exit
# Make the script executable
sudo chmod a+x /etc/init.d/wakeonlan
# Create the init links
sudo update-rc.d wakeonlan defaults

Under Debian the following approach has been chosen:

Deploying weld-osgi to jcoderz.org repository

Sat, 31 Dec 2011 16:36:00 +0100

For deploying weld-osgi to the jcoderz.org repository the following modifications to the pom.xml files are necessary (after applying the wagon-ssh extensions to the your Maven installation, see previous post):

Deploy the WELD API packages

git clone -b WELD-963 http://github.com/mathieuancelin/api.git WELD-963
cd WELD-963
vi pom.xml

Add the following XMl fragment to the maven-deploy-plugin

   <build>
      <plugins>
         <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-deploy-plugin</artifactId>
            <configuration>
               <skip>true</skip>
            </configuration>
            <dependencies>
              <dependency>
                <groupId>org.apache.maven.wagon</groupId>
                <artifactId>wagon-ssh</artifactId>
                <version>2.2</version>
              </dependency>
            </dependencies>
         </plugin>
      </plugins>
   </build>

mvn -e clean install -Dmaven.test.skip=true
mvn -e deploy -DaltDeploymentRepository=jcoderz-snapshots::default::scp://jcoderz.org/var/www/repos/maven2-snapshot/ -Dmaven.test.skip=true
cd ..

2. Deploy the WELD OSGi packages

Maven 3: SSH deployment to foreign repository

Sat, 31 Dec 2011 16:08:00 +0100

Using the maven-deploy-plugin to deploy artifacts to a repository that is not the original target repository of a project is getting complicated with Maven 3 when the wagon SSH provider is not part of the Maven distribution. The following JAR files must be added to the Maven distribution into the lib/ext extension folder:

jsch-0.1.44-1.jar
plexus-utils-3.0.jar
plexus-interactivity-api-1.0-alpha-6.jar
wagon-ssh-2.2.jar\n* wagon-ssh-external-2.2.jar
wagon-ssh-common-2.2.jar

Then the parent pom.xml of the project must be extended by the following lines:

Building weld-osgi

Tue, 06 Dec 2011 23:11:00 +0100

In case you want to use Weld inside your OSGi application you first need to compile a few branches on your own:

WELD-963 branch of the weld/api project
weld-osgi branch from the weld/core project

Those branches will soon be merged into the official Weld codebase. But in the meantime you need to follow the steps below in order to get the packages compiled.
A prerequisite is that git and Maven 3 is available

m3player version 0.1.3 released

Sat, 20 Aug 2011 01:45:00 +0200

m3player version 0.1.3 has the following new features:

m3player can be run as a daemon with -d or --daemon
The name of the UPnP Media Renderer can be configured by -n or --name. This is done by copying the XML files from /usr/share/m3player to /var/lib/m3player and filtering place-holders in some of the files.
The version of the MediaRenderer device can be configured by -r or --root. The default is MediaRendererV2.xml
The UPnP server can be bound to a network interface, specified by -i or --interface. Example: eth0

The help output shows an overview of all the parameters available:

Turning m3player into a daemon

Thu, 11 Aug 2011 21:29:00 +0200

As most of the public HOWTOs seem to be either incomplete or a bit outdated and because I have no copy of the book Advanced Programming in the UNIX Environment, Instead I found the following microHOWTOs:

By following the steps, described there I was able to turn m3player into a daemon. The daemon behavior can be turned on by passing the -d or --daemon switches to the command line. When the daemon switch is specified, all output (stdout and stderr) gets redirected into the log file at the default location /var/log/m3player.log or to the location, specified by the -l or --logfile switch.

m3player version 0.1.2 released

Mon, 01 Aug 2011 01:22:00 +0200

I just released version 0.1.2 of m3player. The new version includes:

Compilation and packaging for OpenWRT
Installation of the ipkg package on the TL-WR1043ND device
Support for command-line parameters:
- config - Path to the config file (/etc/m3player/m3player.ini)
- pidfile - Location of the PID file (/var/run/m3player.pid)
- xmlfolder - Location of the descriptor XML files (/usr/share/m3player)
- name - Set the name of the player instance (Hostname or m3player)
- filename - The name of the root device file (MediaRenderedV1.xml)
Support for an INI file (/etc/m3player/m3player.ini)
Fixes to the GStreamer pipeline to work in the stripped down OpenWRT environment with only a few plugins

When launching the m3player it starts playing the first entry from the preset list.

Building a TP-Link TL-WR1043ND OpenWRT 10.03 image

Sun, 31 Jul 2011 23:48:00 +0200

This article gives a step-by-step description on how to get the m3ddity-player working on the TP-Link TL-WR1043ND device, using the stable version of OpenWRT 10.03 (backfire).

First you need to checkout the OpenWRT 10.03 (backfire) branch:

svn co svn://svn.openwrt.org/openwrt/branches/backfire
cd backfire

Then the feed for the m3ddity-player must be added:

cp feeds.conf.default feeds.conf
echo "src-svn jcoderz http://www.jcoderz.org/svn/m3dditiez/branches/openwrt-10.3/packages" >> feeds.conf
./scripts/feeds update ./scripts/feeds install -a

Now run menuconfig and select the necessary modules:

make menuconfig

The following list shows only menuconfig entries where settings have been changed. Settings not shown here are left untouched.

Music player fully integrated into the OpenWRT build process

Mon, 25 Jul 2011 00:44:00 +0200

The m3ddity-player and the GUPnP libraries, on which the player depends upon, can now easily be build for OpenWRT, just follow the steps below:

1. Checkout the trunk version of OpenWRT

svn co svn://svn.openwrt.org/openwrt/trunk
cd trunk

Add the jCoderZ package repository to the list of feeds

cp feeds.conf.default feeds.conf
echo "src-svn jcoderz " \ 
     "http://www.jcoderz.org/svn/m3dditiez/trunk/" \ 
"openwrt/packages" >> feeds.conf
./scripts/feeds update 
./scripts/feeds install -a

3. Run menuconfig and select the packages as described here

jCoderZ.org

Sun, 24 Jul 2011 13:31:00 +0200

The OpenWRT music player, which I have blogged about recently, has found a home at https://github.com/jCoderZ/m3player

Quest for a USB audio device part 2...

Tue, 19 Jul 2011 20:21:00 +0200

The new audio devices arrived but unfortunately they show the same glitches as the devices I tested before:

USB Soundkarte mit Virtual 3D Soundeffekt LogiLink® This device is also based on the chipset “Tenx Technology, Inc. TP6911 Audio Headset” and has the same issues as the previous device (USB Sound Audio), i.e. the output is far too loud.
USB Soundkarte mit Virtual 7.1 Soundeffekt LogiLink® The sound is good but as with the previous device a clicking noise is heard during reboot, power-off, power-on, plug-in/out. The chipset is “C-Media Electronics, Inc. Audio Adapter” So both adapters use the same chipsets and show the same issues. It seems as if there are not too many different cheap USB audio devices on the market, just rebranded stuff from the same manufacturer.

Seeking a cheap USB audio device for the TP-Link TL-WR1043ND

Wed, 13 Jul 2011 22:48:00 +0200

I’m seeking for a USB audio device that works with the TP-Link TL-WR1043ND under OpenWRT. Until now I tried 2 different devices with unacceptable issues.

1. USB Sound Audio (Amazon)

The device gets detected under Linux as Tenx Technology, Inc. TP6911 Audio Headset. The following warnings are reported by

dmesg when connecting the device:

usb_audio: Warning! Unlikely big volume range (=13568), cval->res is probably wrong.
usb_audio: [2] FU [PCM Playback Volume] ch = 2, val = 2560/16128/1
usb_audio: Warning! Unlikely big volume range (=6096), cval->res is probably wrong.
usb_audio: [5] FU [Mic Capture Volume] ch = 1, val = 0/6096/1

The issue with this device is that the volume level is so high that it cannot be controlled. Between mute and 10% the output sounds distorted. At 20% the volume level is at its maximum, with no audible change between 20% and 100%. 2. auvisio Visual Sound Technologies (pearl.de)

Make ALSA settings persistent on OpenWRT

Wed, 13 Jul 2011 21:36:00 +0200

The command-line tool alsamixer can be used to control the volume of the USB audio output:

Unfortunately the setting does not survive a reboot. Another tool from the alsa-utils package can be used for this purpose: alsactl

After setting the volume with alsamixer, the following command persists the current setting in the file-system for device 0:

alsactl -f /etc/alsa/alsa0.state store 0

During startup, the state must be restored again. This can be achieved by adding the following command to /etc/rc.local:

Building an OpenWRT image optimized for MP3 audio playback

Wed, 13 Jul 2011 20:36:00 +0200

For the audio-renderer, see revious posts, I decided to switch to the trunk version of OpenWRT.
I experienced some issues with the USB audio hardware and the trunk version should prove that there are no issues with the USB audio drivers which are already fixed.
The following configuration is for the bleeding-edge version, some module names have changed so it cannot be applied to the Kamikaze (10.3) version without modification (e.g. block-mount contains the overlay functionality and kmod-fs-ext4 has support for all ext file-system versions).
NOTE: This configuration has stripped all modules which are not necessary for USB audio and Wireless LAN.

Using a password safe on multiple platforms

Sat, 09 Jul 2011 15:40:00 +0200

After the Playstation Network Hack I decided to change to secure passwords for all my accounts. The drawback is that nobody can remember secure passwords anymore, so there is no way around using a password safe.

The only application that is available on all the different platforms I use is KeePass (V1.x on Windows, KeePassX under Linux, and KeePassDroid on Android). Under Windows the the 1.x version must be used in order to stick to the same file format as the KeePassX and the KeePassDroid applications.

Radio presets

Mon, 27 Jun 2011 23:26:00 +0200

One important feature for the audio renderer is the support for presets.

I do not want to search for my mobile phone in order to select a music source when I enter the kitchen in the morning. The use-case where you turn on your analog radio and the tuning wheel is right at the position of your favorite radio station is unbeatable simple.

Therefore the audio-renderer has a list of MP3 streaming URLs where the first one will be played upon startup of the process. The channels can be switched by sending a signal to the server process:

UPnP audio renderer released

Mon, 27 Jun 2011 23:05:00 +0200

A very early version of my UPnP audio-renderer had been released on Gitorius https://gitorious.org/gupnp-audio-renderer (Update 2011-08-01: It has been renamed to m3player and been moved to here). It implements the necessary parts of the UPnP MediaRenderer specification.

The implementation is based on excellent frameworks like:

The initial target for the renderer is the OpenWRT platform (see previous articles about a WiFi music player). I decided to use C instead of Vala (that was a decision against Rygel) as the memory constraints are very limited and I need to save memory whereever possible. Although my C language skills are a bit rusty, I did not want to learn another language. Additionally, the usage of Vala would increase the effort to port the whole vala stuff to the OpenWRT build-system. Luckily GStreamer and GLib are already available on OpenWRT.

Compile a development version of GUPnP from HEAD

Mon, 13 Jun 2011 17:53:00 +0200

Follow the commands below in order to setup a local environment for working with the latest development version of the GUPNP framework.

mkdir $(pwd)/base
git clone http://git.gnome.org/browse/gssdp
cd gssdp
./autogen.sh --prefix=$(pwd)/../base --exec-prefix=$(pwd)/../base
make && make install
cd ..
git clone http://git.gnome.org/browse/gupnp
cd gupnp
PKG_CONFIG_PATH=$(pwd)/../base/lib/pkgconfig ./autogen.sh --prefix=$(pwd)/../base --exec-prefix=$(pwd)/../base
cd ..
git clone http://git.gnome.org/browse/gupnp-tools
cd gupnp-tools
PKG_CONFIG_PATH=$(pwd)/../base/lib/pkgconfig ./autogen.sh --prefix=$(pwd)/../base --exec-prefix=$(pwd)/../base
cd ..

Run the following commands for setting the environment to use the fresh compiled libraries instead of the OS provided ones (Empathy under Ubuntu 11.04 uses an older version of the GUPNP libraries. I ran into segmentation faults because the libraries did not match):

Building a custom OpenWRT image for the TP-Link TL-WR1043ND

Sun, 12 Jun 2011 16:36:00 +0200

[] []

For my low-budget wireless music player I had to tweak OpenWRT in order to support my setup. For initial tests I decided to use the Music Player Daemon and madplay.

The following steps describe how to setup OpenWRT on the TP-Link WR1043ND. It assumes that the OpenWRT 10.03.1-rc4 firmware has already been installed, that the IP address of the router has been set to 192.168.0.111, and that an USB audio, as well as that an USB stick has been connected to the device via an USB hub.

Low-budget WiFi Music Player

Sun, 12 Jun 2011 13:17:00 +0200

After searching the net for quite a while I could not find a pure wireless music player for small money. In case you want to equip multiple rooms in your house with a music player it will cost you a lot of money. All products on the market come with a lot of features, of which most are not necessary. The following links show interesting hacks on how to build your own WiFi music player based on OpenWRT:

GUPNP: Failed to get SCPD: Cannot resolve hostname ((null))

Sun, 05 Jun 2011 18:23:00 +0200

The following message occurs when the <urlbase></urlbase> tag of the root device description is empty when trying to autoconnect actions:

** (process:25888): WARNING **: Failed to get SCPD: Cannot resolve hostname ((null))

Changing it to http://localhost fixes the issue.

<?xml version="1.0"?>
<root xmlns="urn:schemas-upnp-org:device-1-0">
  <specVersion>
    <major>1</major>
    <minor>0</minor>
  </specVersion>
<URLBase>http://localhost</URLBase>
  <device>
    <!-- ... -->
  </device>
</root>

The message is a bit misleading. I was first trying to find an issue with my DNS configuration.

Compiling GUPnP on Ubuntu 11.04

Fri, 03 Jun 2011 15:55:00 +0200

Because the GUPnP stack is lacking some documentation I describe my experiences with getting it complied under Ubuntu 11.04.
The commands will setup an environment that does not interfere with the Ubuntu provided packages, which are older than the ones compiled here. The library files will be installed under the location: ~/workspaces/openwrt/upnp

Download:

mkdir -p ~/workspaces/openwrt/upnp
cd ~/workspaces/openwrt/upnp
wget -O - http://gupnp.org/sites/all/files/sources/gupnp-igd-0.1.11.tar.gz | tar xvfz -
wget -O - http://gupnp.org/sites/all/files/sources/gupnp-0.16.1.tar.gz | tar xvfz -
wget -O - http://gupnp.org/sites/all/files/sources/gupnp-igd-0.1.10.tar.gz | tar xvfz -
wget -O - http://gupnp.org/sites/all/files/sources/gupnp-tools-0.8.3.tar.gz | tar xvfz -
wget -O - http://gupnp.org/sites/all/files/sources/gupnp-dlna-0.6.1.tar.gz | tar xvfz -
wget -O - http://gupnp.org/sites/all/files/sources/gupnp-av-0.8.0.tar.gz | tar xvfz -
wget -O - http://gupnp.org/sites/all/files/sources/gssdp-0.10.0.tar.gz | tar xvfz -
wget -O - http://gupnp.org/sites/all/files/sources/gupnp-vala-0.8.0.tar.gz | tar xvfz -

Prerequisites:

VirtualBox 4.0.2 on Ubuntu 11.04

Sun, 29 May 2011 13:55:00 +0200

After an update to Ubuntu 11.04 VirtualBox was not running anymore. Startup fails with a hint that the kernel modules exited in error and that I should use DKMS to reconfigure the kernel module.

Running the vboxdrv setup command also led to an error:

$ sudo /etc/init.d/vboxdrv setup
[sudo] password for desktop: 
 * Stopping VirtualBox kernel modules                                  *  done.
 * Uninstalling old VirtualBox DKMS kernel modules                     *  done.
 * Trying to register the VirtualBox kernel modules using DKMS                  
Error! Bad return status for module build on kernel: 2.6.38-8-generic (x86_64)
Consult the make.log in the build directory
/var/lib/dkms/vboxhost/4.0.2/build/ for more information.
 * Failed, trying without DKMS
 * Recompiling VirtualBox kernel modules                                        
 * Look at /var/log/vbox-install.log to find out what went wrong

The log file indicates that a header file was missing:

New version of smpppd-web

Thu, 12 Jan 2006 05:46:00 +0100

The original versions of smppd-web by Christopher Hofmann neither support adding and removing links on the fly nor do they support dial-on-demand ISDN interfaces. That is the reason why I extended the original codebase by these features.
Further more the users for which I developed the software are german speaking only so that gettext support was also an important feature. Initially I added support for german and english languages.

As I’m not a SuSE user in general, the new version probably does not follow the SuSE directory guidelines and it does not come packaged as a RPM. Therefore it would be great if someone with SuSE RPM packaging know-how would create a successor RPM package out of Christopher’s original version. Or even better Christopher packages a new version for OpenSuSE ;)

Creating an ISDN Gateway with SuSE 9.3

Wed, 19 Oct 2005 07:31:00 +0200

In Germany flatrates are available for DSL only, so people, living in areas where DSL is not available, have to pay expensive time based fees for slowly connecting to the Internet. The problem is that M$ Windows and many of the installed tools are known for initiating internet connections although the user did not ask them to do so. Therefore it is crucial to reliably disconnect the ISDN line so that those unwanted connection attempts will not succeed. ISDN routers, which might be of help here, are hard to find nowadays and do not offer the comfort as new DSL routers do.

Setting up a free Microsoft debugging environment on Windows XP

Wed, 27 Jul 2005 07:45:00 +0200

This is a short guide on how to debug applications or dynamic link libraries created by the post free Microsoft C++ compile environment.

The following tools need to be installed:

Microsoft Debug Tools (13MB): c:\msdev\debug
Windows XP with Service Pack 2 symbols (195MB)

Then extend your environment’s LIB path by adding the Visual Studio .NET 2003 lib folder. Visual Studio .NET 2003 was installed during the former .NET SDK installation, unfortunately the path, specified for the .NET SDK is not taken as installation path for Visual Studio but the usual program folder is used instead, in my case C:\Programme\Microsoft Visual Studio .NET 2003. Find out the path’s short name with dir /X and add the following line with your specific path to the setenv.cmd script below the three call statements:

More Reverse Engineering

Wed, 06 Jul 2005 09:26:00 +0200

I did more reverse engineering on the DataRecorder Windows tool that comes with the TFA Klima-Logger hygrometer in order to find out which serial lines are used as input lines.

The evaluation version of IDA Pro Disassembler and Debugger did a great job here. The only thing I had to do was to load the executable DataRecorder.exe into the disassembler and find the places where the Win32 API function GetCommModemStatus gets called. A search for the function name revealed two sub-routines inside the huge pile of Assembler code. Looking at the references to data segment constants it was quite easy to determine which of the two sub-routines was the Assembler version of CI2CDriver::Sda() and which one was the Assembler version of CI2CDriver::Scl(). The first sub-routine was referencing an error message

Intercepting Win32 API system calls

Sun, 03 Jul 2005 01:04:00 +0200

For reverse-engineering the Windows software of the TFA Klima-Logger I tried to analyze the I2C protocol over the serial line by intercepting Win32 API system calls.

Searching with Google about the topic intercept Win32 function I stumbled over the Microsoft Research tool Detours which was exactly what I was looking for. Version 1.5 of the tool is freely available for download and already comes with an example to intercept serial API system calls which served as a starting point for my serial communication interception library.

Linux support for TFA Klima-Logger

Sat, 02 Jul 2005 00:23:00 +0200

Update 2012-03-01:
I just ordered 2 outdoor sensors and the plan is to connect the Klima-Logger to a Raspberry Pi Board to make the data available via browser on my home network. Here are some resources I found

Outdated:

I recently bought a hygrometer from TFA-Dostmann, called Klima-Logger. It is the cheapest thermometer and hygrometer with PC connectivity I could find on the market. Unfortunately only a Windows software is provided to get the recorded values for temperature and humidity. I thought a Linux driver would be cool and started searching for resources on the net. Usually the Linux community is very fast in supporting new gadgets of any kind, but nothing could be found.

About

Mon, 01 Jan 0001 00:00:00 +0000

I am a software engineer with over 40 years of hands-on experience, from 8-bit home computers to cloud-native microservices.

My fascination for computers began in 1982 with a Sinclair ZX-81. After exploring home computers like the TI-99 4/A and the VIC-20, I wrote my first BASIC program on a C64 in 1985. I learned 8-bit assembler on the C128, then moved on to M68000 assembler and C on the Commodore Amiga, before transitioning to Turbo Pascal on PC/MS-DOS. From there I worked across many Windows and UNIX platforms, using C/C++ until adopting Java as my primary language around 2000.

Achievo

Mon, 01 Jan 0001 00:00:00 +0000

My role at Achievo Deutschland AG was best described as Technical Lead Software Development. My responsibilities included:

Development process (offshore and nearshore)
Software development guidelines
Definition and compliance checking of quality gates
Technical architecture
Coaching of new developers
Build process and continuous integration strategy
WebSphere Application Server configuration and deployment

On customer projects I served as senior software architect.

TACO - Transparent Analysis and Cost Optimization

The TACO project is a J2EE application which supports the purchasing process of car components for an automotive manufacturer.

Allowance

Mon, 01 Jan 0001 00:00:00 +0000

This application replaces manual paper-based allowance calculations on construction sites with computer-based data entry and reporting.

At startup, the user selects a construction site before proceeding to the main menu.

Main Menu

The first ten menu items provide functions for the collection of allowances. Each mask is preceded by a blueprint number and the resulting item number for the allowance.

Information

Input mask for length, width, and height

Amiga

Mon, 01 Jan 0001 00:00:00 +0000

Several fun programs written in 68000 Assembler on the Commodore Amiga. The purpose of these programs was simply to explore the Amiga’s hardware capabilities and to have fun.

The programs below were tested on Amiga Emulator UAE version 0.6.9 R12.

Misc

The small test application below moves five sprites and draws some lines using the processor only – no Amiga custom chips are involved.

Vector

The first screenshot shows my first working vector graphics algorithm.

Automatic Zapit Satellite

Mon, 01 Jan 0001 00:00:00 +0000

This software provides a set of scripts for automatically generating DBox2 Neutrino channel lists – a workaround for the automatic transponder scan, which does not work reliably on all DBox2 boxes.

Automatic Zapit Satellite (AZS) is a small collection of scripts that extract the Astra digital TV and digital radio channel lists from internet sources and produce the services.xml and bouquets.xml files used by the Linux operating system on the DBox2 digital satellite receiver.

Autotexts

Mon, 01 Jan 0001 00:00:00 +0000

This project involved migrating WordBasic macros to VisualBasic for Applications (VBA).

The company used a large set of Microsoft Word Autotext fragments to generate customer offers. Each fragment described one of their products, and an offer was simply a compilation of different fragments into a single Word document.

The original program consisted of WordBasic scripts that inserted all Autotexts into a document for editing the product descriptions. My task was to convert these scripts to VisualBasic for Applications (VBA).

C64/C128

Mon, 01 Jan 0001 00:00:00 +0000

The Commodore 64 projects on this page were created while teaching myself the BASIC programming language and 6502 Assembler.

The files on this page were converted to the “Virtual Disk” format (.d64) using Trans64 and an X1541 cable to connect an original C64 floppy drive to a PC.

Basic Arithmetics

This program served as both a calculator and a training tool for basic arithmetic.

Clearing and Settlement System

Mon, 01 Jan 0001 00:00:00 +0000

The clearing and settlement solution was developed between September 2004 and June 2005 to process large volumes of chargeable events and produce files for carrying out the actual settlements with a bank.

Architecture

My task in this project was to develop the Finance Calculation Service (FCS). The main design goal was to keep the interface as simple as possible and to avoid any dependencies on other components of the application. The workflow engine was responsible for orchestrating all the different services. It reads the financial base data from the database via the Finance Data Repository (FDR) and feeds those entities into the FCS API. The calculated results are then stored back into the database through the FDR. The design follows the dependency injection principle, where all data is fed into the FCS methods from the outside. This allows the service to run locally without requiring an EJB container or a database.

COM2CORBA

Mon, 01 Jan 0001 00:00:00 +0000

An evaluation prototype for testing CORBA access from VisualBasic applications.

The goal of this prototype was to evaluate whether a commercially available COM2CORBA bridge is suitable for accessing CORBA objects from a Microsoft COM application.

The prototype was developed using an evaluation version of Orbix 2.3 for Windows NT and Sun Solaris, along with the IONA Orbix COMet COM2CORBA bridge.

COM2CORBA prototype architecture

The server component runs on Solaris 5 and provides access to a Fulcrum Search Server, an SGML indexing engine. The client is a VisualBasic search application running on Windows NT.

CORBA 2.2 Validator

Mon, 01 Jan 0001 00:00:00 +0000

A perl script that runs positive and negative test-cases against arbitrary IDL compilers for specification compliance checking.

While learning CORBA, I wrote a set of IDL files and a script to check the compliance of an IDL parser.

The files are separated into categories of valid and invalid IDL fragments. A Perl script picks up the different IDL files and feeds them to the IDL compiler. If the compiler fails on a valid file, or does not fail on an invalid file, the script terminates and reports an incompatibility in the IDL parser under test.

CORBA/CGI Bridge

Mon, 01 Jan 0001 00:00:00 +0000

The CORBA/CGI bridge is an evaluation prototype for testing how a CGI application can be replaced by CORBA components.

The idea behind this prototype was to replace a CGI application that accessed a server-side application with a CORBA layer. The client application had to remain unchanged, as its source code was not available.

In the first step, the CGI application was replaced by a Java servlet deployed on Sun’s Java Web Server. At this stage, the servlet still accessed the server application by executing a command-line script.

DOS International

Mon, 01 Jan 0001 00:00:00 +0000

This article, published in a German PC magazine called ‘DOS International’, was written during a summer C++ course at Saarland University.

Initially, it was intended as a submission for a contest to write a useful program in just 1024 bytes. The prize was 1024 Deutsche Mark, but unfortunately the program was considered too specialized to be generally useful. However, the contribution was later reused in the magazine’s programmer’s corner: ’tips and tricks for programmers’.

Energy Cost Calculation

Mon, 01 Jan 0001 00:00:00 +0000

An application for comparing the cost of traditional power supply against a power generator.

The ‘Energy Cost Calculation’ application was used by the sales department of a company selling electrical generators and standby sets. A sales representative’s typical task was to compare the efficiency and potential savings of an electrical generator against a standard power supply. This application automates most of the steps that previously had to be done by hand.

Homepage

Mon, 01 Jan 0001 00:00:00 +0000

The Homepage project shows the evolution of this website.

The first version of the homepage was simply a project to teach myself HTML. Since version 2.0 I started using it as an online reference page when applying for a new job.

Version 1.0 (199?/?? - 1997/12)

Homepage 1.0

The menu in this version was rendered with the 3D ray-tracing application Lightwave 3D on the Amiga. The big disadvantage of using a full blown image as a menu, is that the menu took a long time to load at the time when 28.8 Modems were state of the art.

IBM

Mon, 01 Jan 0001 00:00:00 +0000

Daimler Vehicle Backend

In June 2018 I started as migration lead to move all microservices from the traditional data center to a modern cloud-based environment. The primary objective was to migrate each microservice without impacting customers. A sophisticated Netflix Eureka synchronization mechanism was established to make the transition seamless for microservices, regardless of whether their peers were still running in the data center or had already been moved to the cloud. This also included a bridge for mirroring messaging middleware traffic from the data center to several cloud-based solutions.

Inventory Management

Mon, 01 Jan 0001 00:00:00 +0000

A solution to create offers from product description fragments, stored in an MS Access database.

This prototype grew out of the VBA project Autotexts. The Microsoft Word Autotext solution did not scale, was unsuitable for concurrent access, and made it difficult to maintain the set of Autotext fragments in a simple Word document template. The company expressed interest in a more professional solution but ultimately decided to go with an already established application.

Knowledge Now 2

Mon, 01 Jan 0001 00:00:00 +0000

My diploma thesis project, focused on CORBA and distributed components. The thesis paper is available as a PDF download below, unfortunately only available in German.

The thesis was written in LaTeX and converted to a fully featured PDF document with pdfTeX, including links, page preview thumbnails, and a table of contents overview.

While working on this project, the following smaller spin-off tools were written:

DDEExecute A command-line tool for issuing Dynamic Data Exchange (DDE) commands to applications that support this Windows API.

Mercedes-Benz AG

Mon, 01 Jan 0001 00:00:00 +0000

Mercedes Intelligent Cloud (MIC)

As Chief Architect for the Mercedes Intelligent Cloud, I am responsible for defining the platform’s technical direction and long-term architecture.

The MIC follows a multicloud strategy spanning Microsoft Azure and AWS, underpinned by a true zero trust model for all inter-service communication. Rather than building central platform teams that risk becoming bottlenecks, we deliver architecture as blueprints, giving DevOps teams full autonomy over their deployments.

A core principle is shift left: enabling DevOps teams to work directly with cloud services and equipping them with the right tooling to strengthen their security posture. GitLab Ultimate serves as our single-tool strategy, reducing cognitive load and allowing teams to stay focused on delivering business value.

Micro Aggregation Engine (MAGGIE)

Mon, 01 Jan 0001 00:00:00 +0000

The MAGGIE prototype was developed as a showcase for the New York public transport agency, demonstrating how RFID-based credit card payments could be used to purchase subway tickets.

The Micro AGGregatIon Engine prototype demonstrates the concept of aggregating small transaction amounts into larger values before settling them against a traditional payment backend such as a credit card or bank account. This kind of system is useful in markets with very low transaction amounts, where immediate settlement fees would exceed the actual transaction value.

MR Computer

Mon, 01 Jan 0001 00:00:00 +0000

This application was developed to support a small business in selling hardware.

A customer orders one or more hardware items, and the user enters the order into the application.

The user can choose hardware items from different dealers. The software automatically splits the order into separate orders per dealer, based on the user’s item selection.

When items arrive from the dealers, they are marked as delivered and then appear on the invoices generated for each customer.

Offer

Mon, 01 Jan 0001 00:00:00 +0000

This application replaced an old, hard-to-use host-based system for creating offers for electrical power generators, providing a much simpler interface.

It was developed to support a sales department in selling electrical generators and standby sets.

The user chooses a generator model and selects various components from a list. The selection is driven by customer-defined requirements.

Main Menu

The menu item ‘Create Offer’ leads the user to a screen where the selection of the generator base model and the optional components takes place.

Orbit Resource

Mon, 01 Jan 0001 00:00:00 +0000

A link collection which was created while doing research about the ORBit CORBA ORB.

The CORBA ORB ‘ORBit’ spawned a large number of spin-off projects, with information scattered across many different websites. That was the motivation for creating an ORBit resource page on SourceForge to serve as a central link collection for all those projects.

ORBit Resource Collection

With the arrival of the ORBit2 project, interest in the old ORBit version has faded, and the page is no longer maintained.

ORBit Time Service

Mon, 01 Jan 0001 00:00:00 +0000

A CORBA TimeService implementation developed for a CORBA ORB with C language mapping.

When I started using Linux on the desktop, I got interested in the small and efficient CORBA ORB called ORBit. The distributed component architecture CORBA is the default inter-process communication protocol used in the GNOME desktop project.

To teach myself the CORBA C Language Mapping that ORBit provides, I wrote the CORBA ‘TimeService’ on top of the ORBit ORB.

Path Editor

Mon, 01 Jan 0001 00:00:00 +0000

A graphical user interface for defining vehicle pathways with real-time control features.

This application was developed during a practical course on real-time systems at Saarland University. The course assignment was to build a vehicle with a real-time controller system. I was responsible for the GUI editor used to create paths for the vehicle to follow. Nikolaus Gerteis handled the hardware and Roland Schlosser developed the micro-controller application.

The 80C166 micro-controller with its various I/O channels implements the fundamental real-time principle of “Input, Processing, and Output.”

PCon 1.2

Mon, 01 Jan 0001 00:00:00 +0000

An application for monitoring productivity in small to medium-sized businesses in the manufacturing industry.

The software was used to provide controlling services to customer companies, primarily regional shoe manufacturers. Collected productivity data was analyzed on a daily, monthly, quarterly, and yearly basis, helping customers improve the efficiency of their manufacturing processes.

Main Window

The program uses a numbering system to classify the different data collections. The numbering encodes the hierarchical structure of the company and its departments. Each department is assigned a 3-part number, where each part represents a level in the organizational structure.

PCon 3.0

Mon, 01 Jan 0001 00:00:00 +0000

A ground-up rewrite of the productivity controlling application 1.2 using the Microsoft Foundation Classes (MFC), aimed at achieving a more polished look and feel and simplifying the user interface.

Version 3.0 introduced the following changes:

Added a flexible employee model (individual employees, groups, and machines).
Added support for data terminals.
Implemented a traceability system for base data.
Added flexible task types (single, combined, group, and long-running).
Used DAO (Data Access Objects) for database access.
Implemented a streamlined installation procedure.
Added employee data import from ERP systems.
Used Crystal Reports V5.0 for reporting.
Added flexible customer management.
Extended Win32 API support.
Removed the hard-to-understand numbering system.
Dropped the hour type concept, as it was inconsistent with the productivity calculations.
Dropped the macro system.

Main Window

PCon 3.5

Mon, 01 Jan 0001 00:00:00 +0000

This extension of Productivity Controlling 3.0 added concurrent multi-user access to the application.

The most important feature in version 3.5 of the Productivity-Controlling (PCon) application is concurrent user support. The original design did not allow multiple users to access the Microsoft Access database at the same time. Since Access itself does not provide concurrent access capabilities, the most practical fix was to introduce a DCOM server component that monitors database access and keeps track of active connections.

Person to Person Payment

Mon, 01 Jan 0001 00:00:00 +0000

An application for mobile phone-based money transfers.

The Person to Person paYment (PPY) prototype was developed in just one week as a showcase demonstrating how a traditional money transfer system could be extended with a mobile phone channel, using SMS to send money orders.

PPY Transaction List

My task was to build the web channel for the PPY prototype. XHTML and CSS, together with Java Server Pages (JSP) and the JSP Standard Tag Library (JSTL), were chosen for developing the page templates. The page flow was kept as simple as possible. Beyond demonstrating the functionality to end users, the prototype’s goal was to build experience with graphical user interfaces, since our team had historically focused on server-side software with little or no UI work.

Publish C/S

Mon, 01 Jan 0001 00:00:00 +0000

Distribution of documents to a remotely hosted web application.

The goal of this application was to provide an administration interface for a web-based information database for expatriates. The interface was used to upload new content to the server systems hosted in Chicago, Illinois, USA.

CountryNet Manager Architecture

The information presented by the application comes from SGML documents indexed by a Fulcrum SearchServer. To update these SGML documents, an administration interface called CountryNet Manager was developed.

Seminar

Mon, 01 Jan 0001 00:00:00 +0000

A presentation about ‘Approaches for the integration of distributed computation into the WWW’

This paper gives an overview of different architectures for smoothly integrating distributed computation into the World Wide Web (WWW). Of the four approaches presented, three address integration at a very basic level. The fourth deals with higher-level problems such as referential integrity and migration transparency.


Type	University Presentation
Environment	Sun Solaris, LaTeX, pdfTeX, vi
Link	slides.pdf (287kB) report.pdf (430kB)

SMPPPD Web

Mon, 01 Jan 0001 00:00:00 +0000

An extension of the web interface to the SuSE Meta PPP Daemon.

Christopher Hofmann created a web-based front-end for the SuSE Meta PPP Daemon (SMPPPD). smpppd-web

My extension to the original codebase was to support adding and removing ISDN links on the fly and allowing dial-on-demand of ISDN interfaces.

My primary user only spoke German, so I added gettext support to the application and translated all texts into German as well.

T-Systems

Mon, 01 Jan 0001 00:00:00 +0000

During my time at T-Systems I worked on the following projects:

Daimler Vehicle Backend

In early 2013, I started as the architect of the Vehicle Homepage project, which is part of the Daimler Vehicle Backend. The entire solution was originally designed on top of an enterprise service bus and application server ecosystem. In 2015, we began a major refactoring of the platform, splitting the monolithic services into smaller microservices using the Spring Boot, Spring Cloud, and Netflix OSS stack. In 2018, this refactoring was completed as a prerequisite for moving the whole system from a traditionally operated data center to a hybrid cloud setup.

Telefax

Mon, 01 Jan 0001 00:00:00 +0000

This application is a wrapper around an MS-DOS fax program, providing a set of fax templates for a fixed set of recipients.

The ‘Telefax 1.0’ application is an extension of an MS-DOS-based fax program.

Recipient addresses are stored in a plain text file and loaded by the application at startup. Each record is mapped to a function key (F1-F10). This makes the application somewhat restrictive, but the requirement was that only a small number of business partners would receive faxes.

Twister

Mon, 01 Jan 0001 00:00:00 +0000

A J2EE/C++ application server running on six different operating-system platforms.

In April 2000, I joined the Twister core team of the Brokat Server Technology Division (STD), where the J2EE Application Server “Twister” was being developed.

At the time, the server was sold as an independent product. Unfortunately, in 2001 the decision was made to stop competing with the big players and to use the server as a platform for internal customers only. That remained the state of the product until July 2004, when the final decision was made to discontinue development of the Twister J2EE application server and move to the BEA WebLogic platform instead.

WebCam

Mon, 01 Jan 0001 00:00:00 +0000

A webcam based on AMIGA M-JPEG digitizer hardware and a collection of scripts to upload the images to an FTP account.

Main Window

This project was an attempt to build a webcam from existing hardware, since professional webcams were very expensive at the time.

Hi8 video camera
Amiga 4000
VLab Motion, a Motion-JPEG digitizer card
Parallel port connection (PC2Amiga) to the PC
Windows PC
AOL ‘50 hours free’ internet access

The video camera is connected to the digitizer board on the Amiga. The digitizer software is controlled by an ARexx script that takes a picture every five seconds and sends it via the PC2Amiga client over the parallel port to the PC. On the PC, a VisualBasic application using the Inet ActiveX control uploads the file to an Internet FTP account. On the server, a cron job moves the uploaded file to a folder on a web server, where it can be viewed in a browser.