Testing with Jenkins, Ansible and Docker

You should optimize your RUN commands. Every time you RUN in a Dockerfile, it creates a new filesystem layer. There&#x27;s a hard limit (42, iirc) to the number of layers that Docker can support.<p>Instead of doing:<p><pre><code> RUN echo bar &gt;&gt; foo RUN echo baz &gt;&gt; foo </code></pre> You could do:<p><pre><code> RUN echo bar &gt;&gt; foo \ echo baz &gt;&gt; foo</code></pre>

<i>At the same time, we need to move fast with development and deliver updates as soon as possible. We want to be able to easily deploy several times per day.</i><p>Genuine question, not intended as any sort of troll: what benefits would people with this philosophy say their organisation gains from routinely deploying multiple times per day?<p>I have nothing against better testing tools or more efficient development processes, of course, and if you have a serious bug then being able to fix it as quickly as possible is obviously beneficial. I just don&#x27;t understand where this recent emphasis on <i>always</i> trying to move fast has come from, or what kind of management strategy someone might use to take advantage of such agility.

I&#x27;ve been using Ansible for a few production-related tasks lately, and think it&#x27;s great. It provides the right level of abstraction, IMHO: you can crack open a playbook, read through it, and know exactly what it is doing. There&#x27;s also a growing number of playbooks if you google around.<p>That said, the biggest downside I&#x27;ve seen with Ansible is reusable components. They have something called Galaxy in beta [1], which should help, although it feels a bit rough yet...<p>[1] <a href="https://galaxy.ansible.com/" rel="nofollow">https:&#x2F;&#x2F;galaxy.ansible.com&#x2F;</a>

Cool stuff! We actually use a similar setup [1], but with the additional hassle of figuring out how to handle hardware connections back to the app. Docker + Jenkins has definitely been a big win.<p>[1] <a href="http://www.appneta.com/blog/automated-testing-with-docker/" rel="nofollow">http:&#x2F;&#x2F;www.appneta.com&#x2F;blog&#x2F;automated-testing-with-docker&#x2F;</a>

Take a look at github.com&#x2F;drone&#x2F;drone for an upcoming CI platform built around Docker. It&#x27;s totally open source, but you can use the hosted version at drone.io as well.