🧨 One-Liners That Get You Back to Your Weekend (Fast Ruby Project Starters)

#coding #docker #programming #ruby

June 13, 2025

It’s Friday. You’re almost done. You just want to test an idea, run a quick prototype, or help a friend without messing up your local environment.

So… enter one-liners. The kind that saves your day (and your weekend). Spin up a full Ruby app using Docker. No setup. No fuss. Just run and go.

I’ve collected my favorite Ruby and framework-based one-liners in a new repo: https://github.com/ggerman/oneliner

Not Everything Should Be a One-Liner…

If you think solving complex problems with one-liners is a terrible idea —

We totally agree (sometimes ).

Good code is clean.

Good applications are maintainable.

Good developers know when not to be clever.

So if you’re into building things the right way — with proper architecture, testing, and long-term thinking —

Let’s write code that lasts longer than your coffee.

Why?

Because speed matters when you’re:

Trying out a gem
Running a script
Booting a whole Rails app
Showing off something cool
Avoiding “it works on my machine” problems

Pure Ruby (Script test)


docker run --rm -it \
  -v "$(pwd):/usr/src/app" \
  -w /usr/src/app \
  ruby:3.2 \
  sh -c "gem install test pry && ruby sort.rb"

Sinatra in a Snap


docker run --rm -p 4567:4567 \
  -v "$(pwd):/usr/src/app" \
  -w /usr/src/app \
  ruby:3.2 \
  sh -c "gem install sinatra rack puma rackup && ruby app.rb"

Visit http://localhost:4567

Rails in One Shot

Create a new Rails app:


docker run --rm -p 3000:3000 \
  -v "$(pwd):/usr/src/app" \
  -w /usr/src/app \
  ruby:3.2 \
  sh -c "apt-get update && apt-get install -y nodejs yarn && gem install rails bundler && rails new rails-app"

Run it:


docker run --rm -p 3000:3000 \
  -v "$(pwd):/usr/src/app" \
  -w /usr/src/app \
  ruby:3.2 \
  sh -c "apt-get update && apt-get install -y nodejs yarn && gem install bundler && bundle install && rails s -b 0.0.0.0"

Grape for APIs


docker run --rm -p 9292:9292 \
  -v "$(pwd):/usr/src/app" \
  -w /usr/src/app \
  ruby:3.2 \
  sh -c "gem install grape rack rackup puma && rackup -o 0.0.0.0"