Tutorial

David Moreau Simard

3 minute read

Ansible is known to be good at running things in the order you write them and that’s why it’s awesome for orchestration. However, I have a use case where I have several similar and long-running tasks to run that do not need to run sequentially. Ansible provides a way to run tasks asynchronously and later recover their result. The problem The problem is that Ansible doesn’t provide a way to limit the amount of concurrent tasks run asynchronously.

David Moreau Simard

3 minute read

How to find a great Openstack provider. Isn’t that a good question ? The Openstack foundation thinks so, too. That’s why it announced the release of the Openstack Marketplace at the last Openstack summit in Atlanta. It’s definitely a step in the right direction towards helping users find trustworthy providers of Openstack services. To be listed, providers must meet basic requirements that are verified by the foundation. The great thing is that the marketplace is not limited to public or private cloud offerings, you’ll also be able to find offers for training or consulting, too.

David Moreau Simard

1 minute read

About a year ago, Andrew Crouthamel launched a kickstarter to produce a free series of videos about the CCNA Cisco certification. Andrew is a Cisco Certified Academy Instructor and he’s actually been teaching CCNA courses so he’s knowledgeable about the training material. I remember the kickstarter pretty well because the pilot video reminded me a bit of the video series about Reddit’s architecture. I didn’t think much of it at the time.

David Moreau Simard

3 minute read

You probably use cat everyday. Did you know that tac existed ? It’s the reverse of cat! (no, really). It allows to reverse the contents of a file or, if used with a pipe, the output of the initial command. Let’s see how it works by sorting a directory listing by timestamp…

ls -alt total 4492 drwxrwsr-t 2 owner group 712704 Mar 23 10:32 . -rw-r–r– 1 owner group 225 Mar 21 16:26 tmp.

David Moreau Simard

3 minute read

If you use Puppet at all, you should be using Hiera if you’re not already ! Hiera is a powerful key/value lookup tool for configuration data for puppet. Here’s some quick tips on how you can use it. Puppet 3 ships with Hiera by default so that’s a good start… Using Hiera For the first example I’ll be showing in this post, i’ll be using the following simplistic files and configuration: