wagl is a DNS server which allows microservices running as containers on a distributed Docker Swarm cluster to find and talk to each other. It is minimalist and works as a drop-in container in your cluster.

This article is intended to describe inner workings of wagl and give a broader sense of the state of service discovery problem in today’s container clusters. Read More →

We just had another fantastic Docker Seattle Meetup last week with speakers from Microsoft, Datadog and SumoLogic. I presented my latest side project “wagl” –a DNS service discovery tool for Docker Swarm. I open sourced it live on stage and did a demo of it (I’ll write about this in my next blog post).

The video recording is available on Vimeo —skip to 22:00 for my presentation: Read More →

Instance metadata service is a server available to virtual machines hosted on the cloud providers (often at http://169.254.169.254/). It provides useful information about the VM itself and its environment, which the VM typically does not have access to.

It is often used to configure and distinguish VM instances from each other in scripts and helps a great deal in bootstrapping cluster orchestrators such as Kubernetes, Mesos etc. Read More →

With the upcoming release of Docker 1.9, Docker Volumes feature just got a whole lot better. We can now extend Docker with plugins such as volume drivers, which can manage and mount non-trivial volumes. Last week I wrote a Docker volume driver for the Azure File Service —an offering of Azure cloud that allows you to store files using network file sharing protocol and REST APIs. This service is generally available as of today. Read More →

I recently gave a talk at LinuxCon 2015 North America in the ContainerCon track about “Writing Container-Friendly Applications”. The talk is about how we can take advantage of very simple OS built-ins and apply some common sense to design beautiful services and command-line tools that can live happily inside the containers. You can find the slides below in this post or here. In the talk, I gave some examples of bad practices from popular (but somewhat old) open source projects (such as Apache HTTPD, NGINX, Cassandra, MySQL) now containerized as Docker Official Images and what makes them so hard to create Docker images of them in terms of practices they apply for dealing with configuration, logging, execution modes and so forth. Read More →

Last year, out of boredom, I wanted to redesign the Microsoft employee badges. I just got a piece of paper, started scribbling and in a couple of hours I came up with a design that I later published as “The Blue Badge – Reimagined”. This concept design received huge love internally at Microsoft as well as externally on Hacker News, Designer News, Reddit and many other platforms. At this point it is a good idea to admit that I am not a designer, I am a software engineer and this is not my day job. Read More →

I have been guest of Scott Hanselman on our weekly #AzureFriday show last week. We talked about Docker 101 and some new cool Docker features on the Visual Studio Docker plugin. Thanks Scott for having me! Read More →

I spent the last two months porting the Docker command line interface to Windows with my colleagues on the Microsoft Azure Linux team. Starting with Docker 1.6, a Windows client is shipping with Docker’s official release. This is my first time heavily participating in the development of an open source project and I want to tell you how awesome it was. We recently announced the first version of “Docker Client for Windows” on Azure Blog and on Docker Blog and this is the making-of story of it! Read More →