Many people use docker from the command line to build images, run containers and manage Docker on their machine. However, you can also run the same Docker commands via its remote REST API. In this blog I will guide you through Docker’s remote API using curl while pointing out a few details and tools that […]
NLUUG DevOps Conference 2013 – Reliability, clouds and the UNIX way
Last Thursday I attended the NLUUG DevOps conference in Bunnik, near Utrecht. The NLUUG is the Dutch UNIX user group. In this blog I will summarize the talks I attended, some fun things I learned and I will discuss my own talk about continuous integration at a large organization.
Puppet from the trenches – How to prevent overwritten user configuration with a custom type
In this installment of the ‘from the trenches’ series I cover the use of Puppet during one of our projects. We have used Puppet to provision Jenkins instances as part of a build and deployment platform for a large organization. I discuss the problem of when Puppet overwrites user managed configuration and how we solved […]
Using Docker to efficiently create multiple tomcat instances
In my previous blog article I gave a short introduction into Docker (“an open-source engine that automates the deployment of any application as a lightweight, portable, self-sufficient container that will run virtually anywhere”). In this article we’ll check out how to create an image for Tomcat 7 and the Java 7 JDK as dependency. So, let’s […]
Ansible from the Trenches
Although its name might suggest something different on Wikipedia, Ansible is an open source framework that is capable of automating various system tasks like setting up a server, deploying and configuring applications and command execution (See Ansibleworks.com). Ansible can run across many virtual machines without the need to augment it with other tools. For distribution […]
Next step in virtualization: Docker, lightweight containers
Lately, I have been experimenting with Docker, a new open source technology based on Linux containers (LXC). Docker is most easily compared to Virtual Machines (VMs). Both technologies allow you to create multiple distinct virtual environments which can be run on the same physical machine (host). Docker also shares characteristics with configuration management tools like […]
Ansible – Simple module
In this post, we’ll review Ansible module development. I haven chosen to make a maven module; not very fancy, but it provides a good support for the subject. This module will execute a maven phase for a project (a pom.xml is designated). You can always refer to the Ansible Module Development page. Which language? The […]
Ansible – Example playbook to setup Jenkins slave
As mentioned in my previous post about Ansible, we will now proceed with writing an Ansible playbook. Playbooks are files containing instructions that can be processed by Ansible, they are written in yaml. For this blog post I will show you how to create a playbook that will setup a remote computer as a Jenkins […]
Ansible – next generation configuration management
The popularity of the cloud has taken configuration management to the next level. Tools that help system administrators and developers configure and manage large amounts of servers, like Chef and Puppet, have popped up everywhere. Ansible is the next generation configuration management. Ansible can be used to excute tasks on remote computers via SSH so […]