Installing Rackspace command line tools on CentOS

A set of command line tools is available for the Rackspace cloud computing platform which allows you to e.g. list images and create virtual machines. The installation of this set can be achieved with the following commands: yum install python-setuptools easy_install pip pip install rackspace-novaclient The information that the nova client needs is obtained from […]

Android mobile network settings for Vodafone business in the Netherlands

The following settings are needed for using the Vodafone business mobile network in the Netherlands with an Android phone: Name Choose one yourself, e.g. Vodafone Business Android APN Proxy not set Port not set Username vodafone Password vodafone Server not set MMSC MMS proxy MMS port 8799 MCC 204 MNC 04 Authentication […]

Installing Apache Libcloud on CentOS

Apache Libcloud is a standard Python library that abstracts away differences among multiple cloud provider APIs. At the moment it can be used to manage four different kinds of cloud services: servers, storage, loadbalancers and DNS. Here are the steps to install Libcloud on a machine running CentOS 6: rpm -Uvh yum install python-pip […]

Creating a Java WebStart (JNLP) application

Java WebStart, also called Java Network Launching Protocol (JNLP), allows you to launch Java applications directly from the internet using a webbrowser. In this article we will create a simple application and all configuration files necessary to launch it through Java WebStart. We start with a simple Java program with a GUI: package nl.jansipke.samplegui; import […]

Using the pipe backend in PowerDNS

PowerDNS is a Domain Name System (DNS) server with a lot of different possible backends, such as MySQL, PostgreSQL, LDAP, BIND zone files and a Unix pipe backend. In this article we will look at the pipe backend which is passed the DNS request by PowerDNS through standard input (stdin) and must reply through standard […]

Creating network diagrams with D3.js

D3.js is a JavaScript library for manipulating documents based on data. It can be used for all sorts of visualizations including network diagrams. In this article we will create a network diagram with nodes and directed links between them, visualized by circles and lines with arrowheads. We start with the file index.html that holds the […]