Docker use and challenges


Docker is an open-source engine that automates the deployment of any application as a lightweight, portable, self-sufficient container that will run virtually anywhere. You can encapsulate any payload, without concern of  server type for the most part. Using Docker allows infrastructure to use the same environment that a developer builds and tests on a laptop to then run and scale as needed. It can take and run in production, on VMs, bare-metal servers, OpenStack clusters, public instances, or combinations of the above. The typical environment developers are using currently is call Vagrant ( This is a tool that allows developers to create a lightweight reproducible environment that is also considered portable. Vagrant 1.5 recently released and is an easy install.

So why am I talking about Docker? As I am not a big Google fan on most things I will not talk about lmctfy ( I don’t there is enough adoption of it to warrant a discussion yet. In 6months that may change. With Docker a few features that jump out make it compelling. Cross Cloud compatibility along with incremental images and builds. Global image portability and delivery are done via the Registry.   It is however powerful from the standpoint that Docker usually imposes little or no overhead since programs use a virtual partition and run as a normal application and do not need any emulation as traditional virtualization does. This means that you could have a single instance on a physical machine or just deploying the resource seamlessly as PaaS. Horizontal and vertical scale is a big thing here.









8 Responses to “Docker use and challenges”

  1. 1 Kevin April 2, 2014 at 8:07 pm

    I don’t think you’re correct regarding the restriction on the base image. The kernel is shared by the containers, not the entire distro

    • 2 cuball April 2, 2014 at 9:24 pm

      I guess I should have written it better, but I was aware that the kernel was shared with the containers. What did I say was a restriction on the base image? The only restriction that I can think of is that you are confined to the same OS of your host server. Let me know as I would like to be correct in what I write about on my blog.

      Thanks for the feedback.

      • 3 Helder Correia (@heldercor) April 9, 2014 at 3:45 pm

        You keep saying that you’re restricted to your host’s OS, but you’re incorrect. That would defeat the purpose of docker.

        You can indeed have docker in an ubuntu machine running centos containers. Please fix your post.

        What you can’t do is have a linux container in a BSD system as of now (that will change, unless it already has).

        So it’s not the OS per se, but the kernel itself that is the restriction, which is independent of the distro.

      • 4 cuball April 10, 2014 at 2:08 pm

        Thanks, I think someone below had also said it. I had too much travel until today to get back to this and make the change. Thanks again. Just learning and blogging at the same time. Bound to be wrong from time to time 😉

  2. 5 Alexey Lebedeff April 2, 2014 at 9:00 pm

    “You are confined to the OS that your host server is using. So if the physical server is loaded with Ubuntu or CentOS you can only create a Ubuntu or CentOS container respectively.”

    Why? You could run any linux distro for the same architecture as that on the host machine.

    • 6 cuball April 2, 2014 at 9:40 pm

      Well it allows you to scale horizontally your application without the overhead of a traditional hyper-visor and use only the resources you need to run the application.

  1. 1 artodeto's blog about coding, politics and the world Trackback on April 2, 2014 at 7:53 pm

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