1. Ruby language (https://www.ruby-lang.org)
optional:
2. Docker (https://www.docker.com)
3. Minikube (https://minikube.sigs.k8s.io)
4. Helm (https://helm.sh/)
$ gem install bundler
$ bundle install
$ bundle exec puma
access with browser: http://localhost:9292
$ docker build -t simple-dsl-web .
$ docker run -p 8080:9292 -it --name simple-dsl-web simple-dsl-web
access with browser: http://localhost:8080
$ cd charts/simple-dsl-web
$ helm lint
$ helm package .
$ helm install simple-dsl-web-0.1.0.tgz
access with browser: http://simple-dsl-web.svc.local