This blog post is a continuation of part 1 that had focused on the the installation process of Active Admin. In the current post, we show how Active Admin can be used to migrate from a configuration file based approach by an admin portal based…
Rails Active Admin Installation Experiences / HowTo
In this post, I have recorded my experiences with ActiveAdmin, a Rails Engine that has following goals (copied from their readme file): Enable developers to quickly create good-looking administration interfaces. Build a DSL for developers and an interface for businesses. Ensure…
Upgrading Rails to 4.2.x and Ruby to 2.2.x — an end to end Example
In this post, I have recorded my experiences when upgrading my hobby Web Application, a ProvisioningEngine front end from Rails 4.1.x to Rails 4.2.x and ruby from 2.1.x to 2.2.x. The upgrade went relatively smoothly, apart from an additional gem…
CCIE Written HowTo — where to get the Questions from (also for MCSE and others)
Every two years, I need to re-certify for the Cisco Certified Internetworking Expert certification (CCIE). This time I intend to post my findings on this blog. I intend to describe where to get Example Questions from and how to read them (works for…
Salt Hello World
This a simple Salt Hello World similar to the Ansible Hello World in part 1 of this series. In each step, we will discuss the likeliness and differences between Salt and Ansible. This post is (almost) self-contained, and there is no…
Ansible Templating – A Hello World
This post is a continuation of my previous post, where we have gone through a little "Hello World" example using Ansible, an IT automation tool. Last time we had performed SSH remote shell commands. This time, we will go though a little…
Ansible Hello World – Ansible vs. Salt vs. Chef vs. Puppet
This is part 1 of a little Ansible Hello World example, an IT automation tool. The post has the following content: Comparison of the popularity of Ansible, Salt, Chef, and Puppet Installation of Ansible based on Docker Simple Example Playbooks (i.e.…
Docker Java Performance Tests
In this blog we will show the surprising result that Docker on Ubuntu seems to outperform Docker on CoreOS by ~30%, when tested with a java templating web service. But first let us discuss the reason on why I have started the…
Java Build Automation Part 1: Create lean executable jar using Maven
Have you ever tried to create an executable jar file, while keeping all configuration files outside of the jar file, accessible to operations folks? Here is a step by step guide. JAR files are java archive files and as such, are not…
Source Code to Docker Image — automated Build
What, if you could release and deploy fully tested and bullet-proof software on a day by day basis? Isn't this a huge effort for hobby developers like me? Even for hobby developers, Docker and its ecosystem promises an easy way to…
What is Docker? An Introduction into Container Technology.
Short Introduction into container technologies and reasons, why I have chosen to start proof of concepts with Docker and no other container technology.
Docker Performance Tests for Ruby on Rails
In a series of performance tests, we could show that a (Rails) web application has 50% higher performance on docker (installed on Windows/boot2docker) than the same application run natively on Windows, no matter whether or not the database and program code is located on a shared volume. However, if such a shared volume is auto-mounted to one of the Windows C:\Users folders, the performance drops by a factor of almost ten.
Docker CoreOS Cluster in less than 10 Minutes
Install a Docker Cluster in less than 10 Minutes This blog shows, how a Docker CoreOS cluster can be set up in ~10 minutes (dependent on your Internet speed), excluding the time to install Vagrant, Virtualbox and git. In order…
Docker CoreOS Cluster Failover Test in less than 15 Minutes
In this post, I will explore services failover scenarios for docker containers on CoreOS clusters using fleet. A container-based service will be defined and started, and we will explore the service recovery after a failure of one or all cluster nodes (e.g.…
Container Orchestration with Kubernetes
This blog post shows a quick way how to install Kubernetes, a Docker orchestration framework published by Google, as a set of Docker containers. With that you can circumvent the hassle you may run into while trying to install Kubernetes natively.…
