A Docker Workshop

In Fudcon Pune 2015 we had conducted a Docker introductory workshop. It was well attended and  we got positive feedback about it.  While preparing for the Linux container track in Fudcon we had decided that we will put all the documentation in github. The idea was to keep the content open for collaboration so that others can contribute and reuse the content. Thanks to Neependra for the idea.

Here is the github link which has the workshop content.

The github project also contains some useful material e.g. Hands on Kubernetes which you might useful.

This workshop will take around 3 hours to complete. This is really useful If you are new to docker and wants to learn by doing some hands on.

Multi-Container Application Packaging With Nulecule

I got an opportunity to talk about “Project Atomic and Multi-container application packaging”  in recent docker meetup Bangalore. I have posted my slides to slideshare [1].

However I thought of giving more context and further pointers to the presentation through this blog.

As mentioned in my slide, Nulecule is a specification to define a multi-container applications.  So that we can get rid of the custom shell scripts, long docker run commands, moving the required configuration files and instructions about how to deploy the application to the end user.

Checkout the YouTube video about why we need  Nulecule: From the Nulecule Nest to an Atomic App

However just having a specification will not solve the problem. We need a code to do the required work to run multi-container application using Nulecule specification and that is Atomic App project .

Atomic App performs all actions to run the application by reading the Nulecule spec. Atomic App is used as a docker image.

To run the Atomic App installer for your application , atomic command line is used.

Here is the workflow if you want to build Atomic App installer for your application using Nulecule specification.   Please keep in mind that when I say application, I am actually talking about multi-container application.


Write Nulecule specification files. Which also  includes manifesto files for underlying required orchestration platform (e.g. Kubernetes, OpenShift, Docker Compose, Apache Mosos Marathon etc)

Here is a blog from Ratnadeep about how he created a nulecule-ized application -> http://www.rtnpro.com/nuleculizing-an-docker-image/


Create the layered docker image (use Atomic App docker image as base image) of the application. Which will include Nulecule specification and Atomic App code.

You can push the new image to your local docker registry or public docker hub for your use.


Running the Atomic App image for the application. Here is a example of running a helloapache Atomic App -> https://hub.docker.com/r/projectatomic/helloapache/

Note that there are three way to run an Atomic App i.e.

  • Option 1: Non-interactive defaults
  • Option 2: Unattended
  • Option 3: Install and Run

Here is a YouTube video which shows a demo : WordPress Nulecule Demo

For further read check  Vasik’s presentation or Nulecule github project.

Get Involved:

Nulecule Poject: https://github.com/projectatomic/nulecule
Atomic App: https://github.com/projectatomic/atomicapp

Check the README files of the above projects for relevent communication channels for participating in the project.

[1] http://www.slideshare.net/then4way/project-atomicnulecule
[2] http://www.rtnpro.com/nuleculizing-an-docker-image/
[3] http://www.slideshare.net/VavPavl/nulecule

Linux Container Track at FUDCon, Pune 2015

FUDCon is the Fedora Users and Developers Conference, a major free software event. It is an annual event per region (e.g. APAC). This year FUDCon APAC is  happening at Pune, India From 26th June to 28th June 2015.  For details check out the FUDCon India home page.

FUDCon is always free to attend for anyone in the world. If you are looking for open source and free software contributors/developers, learn latest/new technologies, learn how to contribute to Fedora and other upstream projects, want to hangout and hack on interesting stuff , it is one of the finest place to be present.

This year we are having a Linux container track in FUDCon for full day. The idea of a separate track came because of the more number of talks/workshops proposals submitted related to containers and high interest from community about learning Linux containers e.g. Docker related technologies.

To start with, we have a talk about “Running Project Atomic and Docker on Fedora” in the main track by me and Aditya on Saturday, 27th June 2015. And the container track is on next day i.e. Sunday 28th June 2015.

Here are the list of talks and workshops planned for the container track.

Note : The topics of the container track has changed from the time I had published the blog.  So the I have updated the above list.

For the workshops, you need to carry your laptop. We are planning provide preconfigured virtual machine images for KVM and Virtual box. Also planning to distribute the images using use usb sticks/thumb drives. So if you have usb/thumb drive, please carry them with you as it will help you/others to quickly set-up their environments.

So if you are interested to learn about Linux containers or hack around Linux containers, Docker, come join us on container track in FUDCon 2015, Pune.

DevConf 2015

It was a wonderful experience attending Devconf 2015 in Brno, Czech Republic. The conference hosted some really interesting talks.

Talks I attended

  • Keynote:The Future of Red Hat
  • What is kubernetes?
  • Docker Security
  • Fedora Atomic
  • Performance tuning of Docker and RHEL Atomic
  • GlusterFS- Architecture and Roadmap
  • golang- the Good, the bad and the ugly
  • Vagrant for your Fedora
  • CI Provisioner – slave and test resources in Openstack, Beaker, Foreman, and Docker through one mechanism
  • Effective Beaker(workshop)
  • Project Atomic discussions (not listed in the schedule but interested folks got together)
  • Running a CentOS SIG (My talk)
  • CentOS: A platform for your success
  • Super Privileged Containers (SPC)
  • Ceph FS development update

Apart from this I had attended talks but were not useful to me for various reasons. Hence did not list them.

Most of the talks were live streamed and recorded. You can find them at Red Hat Czech’s youtube channel i.e. https://www.youtube.com/user/RedHatCzech

Because of time constraints I missed some of the good talks too e.g. systemd and open shift talks.

Also because of Devconf, now I can put faces to may irc nicknames and email address. It was a nice experience meet people physically with whom I had only communicated through irc and emails.

A lot of thanks to the organisers, speakers and participants for the success of Devconf 2015. Looking forward to the next Devconf.

Bangalore CentOS Dojo, 2014

The first CentOS Dojo in India took place in Bangalore on 15th November(Saturday) 2014 at Red Hat Bangalore office. Red Hat had sponsored the event.

I was  a co-organizer of the Dojo along with Dominic and Karanbir Singh.  Around 90 people RSVPed  for the event but around 40 (mostly system administrators and new users) attended the event.

The First talk was by Aditya Patawari on “An introduction to Docker and Project Atomic”. The talk included a demo and introduced audience to docker and Atomic host. Most of the attendees had questions on docker as they had used or have heard about it. There were some questions about differences between CoreOS and Project Atomic. The slides are available at http://www.slideshare.net/AdityaPatawari/docker-centosdojo. Overall this talk gave fair idea about Docker and Atomic project.

Second talk was “Be Secure with SELinux Gyan” by Rejy M Cyriac. This session about troubleshooting SELinux issues and introduction to creating custom SELinux policy modules.  Rejy made the talk interesting by distributing SELinux stickers to attendees who asked interesting questions or answered questions. Slides can be found here.

After these two talks we took a lunch break for around 1 hour.  During the lunch break we distributed the CentOS t shirts and got a chance to socialize with the attendees.

The first session post launch was “Scale out storage on CentOS using GlusterFS” by Raghavendra Talur. The talk introduced the audience to GlusterFS, important high level concepts and a demo was shown using packages from CentOS storage SIG. Slides can be found at slideshare.

The next session was “Network Debugging” by Jijesh Kalliyat. This talk covered all most all basic concepts/fundamental, network Diagnostic tools required to troubleshoot a network issue. Also  it included a demo of use Wireshark and Tcpdump to debug network issues. Slides are available here.

Before the next talk, we took break for some time and clicked some group pictures of all present for the Dojo.

The last session was on “Systemd on CentOS” by Saifi Khan. The talk covered a lot of areas e.g. comparison between SysVinit and systemd,  Concurrency at scale, how systemd is more scalable than other available init systems, some similarity of design principles with CoreOS and how it is suited better for Linux container technology. Saifi also talked about how systemd has saved his system from being unusable.  His liking for systemd was quite evident from the talk and enthusiasm.

Overall it was an awesome experience participating in the Dojo as it covered wide variety of topics which are important for deploying CentOS for various purposes.

Bangalore Dojo link: http://wiki.centos.org/Events/Dojo/Bangalore2014

Group Photo. You can see happy faces there 🙂


Bangalore Dojo, 2014