Running a functional-programming workshop without losing the first forty minutes to “does everyone have Erlang installed?” is harder than it looks. Zack Design’s elixir-dojo wraps Eric Meadows-Jönsson’s well-loved Elixir workshop in a reproducible Docker image, so a room full of developers on Macs, Windows laptops, and random Ubuntu VMs can start writing Elixir within minutes.

The setup problem

Elixir runs on the BEAM, which means installing Erlang, then Elixir, then mix, then the right versions of each — and then hoping nothing conflicts with whatever your host OS already has. At a half-day workshop, that friction is the difference between “I wrote my first GenServer today” and “I fought my package manager today.”

The dojo

Clone, build, run:

git clone [email protected]:isaacrowntree/elixir-dojo.git
cd elixir-dojo
git clone [email protected]:ericmj/workshop.git
docker build . -t elixir_dojo
docker run -it --rm -v $(PWD):/code elixir_dojo bash
cd workshop && cd labX && mix test

The volume mount means participants edit files on their host OS using whatever editor they like — VS Code, vim, Sublime, IntelliJ — while the BEAM, mix, and the test runner all live safely inside the container.

Why it matters

Elixir is, in my view, one of the most pleasant languages to pick up once you clear the tooling hurdle — pattern matching, supervision trees, and immutable data structures all feel obvious in a way they rarely do when you read a textbook. A dojo is an ideal on-ramp: small labs, clear goals, a partner to pair with, and failing tests that turn green as you start to get it.

If you are running an Elixir intro session with your team, fork the repo and save yourself the tooling tax. Huge thanks to Eric for the original workshop material that this dojo wraps around.