This is a sample app for the Rails 5.2 Credentials and Kubernetes post.
The interesting parts are:
Dockerfilebuilds minimalistic Docker image with the app
.dockerignoretells Docker to ignore
script/releaseis a script for building and pushing Docker image
config/deployment.ymlis Kubernetes Deployment spec that uses Kubernetes secret management
app/controllers/helloworld_controller.rbrenders decrypted secrets as HTML