Docker Captains are select members of the community that are both experts in their field and are passionate about sharing their Docker knowledge with others. “Docker Captains Take 5” is a regular blog series where we get a closer look at our Captains and ask them the same broad set of questions ranging from what their best Docker tip is to whether they prefer cats or dogs (personally, we like whales and turtles over here). Today, we’re interviewing Sebastien Flochlay who recently joined the Captain’s Program. He is a Tech Ambassador and Co-Founder of Stack Labs and is based in Toulouse, France.

How/when did you first discover Docker?

I discovered Docker in 2016, during my first meetup. It was a Software Craftsmanship group that presented an interesting tool — Docker!

It was an amazing discovery for me! Simplicity, rapidity, portability, and scalability —  I had just discovered containerization.

Today, Docker is an integral part of my daily life as a developer. I deliver my applications in Docker images. I build and run my CI/CD pipelines into Docker containers. I deploy locally my development environments using Docker compose or Kind. And I use Kubernetes or Google Cloud Run for release.

What is your favorite Docker command?

My favorite command is definitely this one: docker run.

It’s the most complete and interesting, yet it’s certainly with this one that you started.

In fact, it’s through this command that we discover the world of Docker. It’s with this command that we learn how and why to publish container ports, manage volumes, or define environment variables. It’s with her that we learn to play with the Network or to control how much memory, or CPU a container can use.

In short, it’s definitely my favorite docker command line.

What is your top tip for working with Docker that others may not know?

I don’t have any secret pro tips, just simple advice: learn how to write Dockerfiles correctly.

Most of the time, when I help a team on their Docker usage, the errors are focused on the Dockerfiles and their writing. There are tons of best practices for writing a Dockerfile (ex. exclude files with a .dockerignore, use multi-stage builds, minimize the number of layers, and so many more), so use them!

If you are interested, there is an amazing documentation page on the subject: https://docs.docker.com/develop/develop-images/dockerfile_best-practices/

What’s the coolest Docker demo you have done/seen?

I’ve seen so many that I can’t choose. But I take this opportunity to thank all those who work to share their knowledge on Docker.

What have you worked on in the past six months that you’re particularly proud of?

I created a 3-day training on Flutter. I put a lot of time and energy into it, and finally, I had the chance to perform it several times, and I liked it. I’m really proud of it! 😋

What do you anticipate will be Docker’s biggest announcement this year?

I would say Docker extensions, but that’s cheating. Eva Bojorges told me about it at the Devoxx2022 conference. 🤫

What are some personal goals for the next year with respect to the Docker community?

I’d like to create some training resources on Docker such as videos, blog posts, workshops, or meetups. I don’t know yet, but I want to participate in the Docker community.

What was your favorite thing about DockerCon 2022?

There are two things that I really liked. The first is Shy Ruparel’s excellent workshop “Getting Started with Docker“. It’s a perfect and very complete introduction to Docker. It’s only been a month, and I’ve already recommended it to three development teams.

The second is Amy Bass’ “What are Docker Extensions” presentation, which gave me a quick understanding of what it was.

Looking to the distant future, what is the technology that you’re most excited about and that you think holds a lot of promise?

I’m excited to see how Flutter develops over the next few years. It is an easy-to-access, very comprehensive technology that opens up many possibilities. 

Rapid fire questions…

What new skill have you mastered during the pandemic?

I learned to develop on Flutter with Dart.

Soon after, I worked on different projects for different clients. 

Then, I created a training on Flutter to pass on what I had learned. Now I have the chance to do many talks on this subject.

Cats or Dogs?

Cats, dogs, lizards, snakes, octopuses, or spiders. I love all animals!! ❤️
Except centipedes! I hate centipedes!! 🐛😱

Salty, sour or sweet?

Salty or Malty (I like beers 😋)

Beach or mountains?

Mountains! I like hiking in the mountains, walking in the forest, or strolling along the rivers. 

Your most often used emoji?

😋