Marianna Tessel

Perspective from the Inside: A Couple Weeks In

After my first few weeks at Docker, I wanted to quickly follow up on my first blog post.

First off, I would like to share my progress towards my promised contribution to the Docker open source project. I made two pull requests:

  1. A Docker image that lets you convert an image to an ascii image. I used the jp2a utility for it. Try it out for yourself:

To run it:

$ docker run -it mtesselh/jp2a <url to your favorite image>

Here is an example:


I made a request to make it an official image but, while everyone had fun playing with the new image, it was deemed not suited to be an official image for the Docker Hub Official Image library. It is now in my Docker Hub account where you can access it using the above command.

  1. I also fixed a simple bug, here is the link (forgive my typo in the title, it was late):

It was officially merged into Docker!

Thanks to crosbymichael nathanleclaire for helping me with these contributions.

Working through these two PRs helped me learn the architecture and appreciate Docker more fully. It also built my trust in the open source process. I actually liked the fact that my request for creating an official image was declined. That was because most official images are general-purpose building blocks while my image was more of an app and so didn’t fit the bill. It is great that the integrity of the project is held to a high standard.

Other random things I’ve observed and learned:

  • Go doesn’t seem too hard to learn if you know C.
  • Attending AWS re:Invent was great. Talking to users and hearing about how they use Docker was eye opening. Even though we brought 1500(!) t-shirts with us, we didn’t have enough to give to all the people who stopped by the booth.
  • Here is a photo of the line of people waiting for the Docker-led session at re:Invent.


  • More than 1400 people signed up and another session was offered to meet the incredible demand.  Now I’m getting ready to for the same kind of enthusiasm for our own DockerCon Europe this week
  • Working in and commuting to San Francisco has pluses and minuses:
    • Pluses: good places for coffee and food; lots of other startups around to collaborate with.
    • Minuses: I need to get used to a longer commute.
    • Oddities: all sorts of things you have to do in the city. For example, I actually had a formal orientation to the parking garage. Really!
  • Animal friendly: Everyone thinks of whales when they think of Docker, but the big animal “on campus” at the Docker offices is a tortoise named Gordon. He has been around since the dotCloud days and has been developing rather nicely. On a nice day, he likes to roam around on our desks.

I thought it will be a good idea to finish up with the following ASCII image of Gordon generated by my jp2a container:


Happy Holidays and see you at DockerCon Europe in Amsterdam!


Marianna Tessel

Perspective from the Inside: A Couple Weeks In

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