Testing Rails apps in Docker (unzip archive in the container)

setup.sh

#!/bin/bash

# Create an empty dir which contains only the .zip file of your app
# Copy this file to your app dir
# Save it as `setup.sh`

# Then run it via:
# docker run --rm -it -p 3000:3000 --volume $PWD:/sandbox ruby:3.2.0-bullseye ./sandbox/setup.sh

set -eux

mkdir /app
cd /app
unzip /sandbox/app.zip

# Assuming the zip archive politely unzips into a new child dir
cd some-dir-name

apt update
apt install -y rbenv

# Ensure later Ruby versions are available
git clone https://github.com/rbenv/ruby-build.git "$(rbenv root)"/plugins/ruby-build

rbenv install 3.0.1

# Ensure rbenv env is set up and available
eval "$(rbenv init -)"

# Install application dependencies
bundle install

# Add any instructions required to set up and run the app below here

rails db:create
rails db:migrate

# On MacOS bind to 0.0.0.0 and then visit http://0.0.0.0:3000/
./bin/rails server -b 0.0.0.0