hello-kupe is our hello world app.
It’s a small go based demo app that helps us prove all platform components are healthy. It emits a constant stream of structured logs and can be deployed into any Kupe Cluster.
In other words, it is a tiny thing we can throw at a cluster and see if all components are happy.
Why have a demo app at all?
It allows us to have a known thing we can use to help onboard with, its behaviour is known and it’s boring enough that it doesn’t get in the way.
If it fails to deploy, route traffic, emit logs, expose metrics, or pass a health check, the question isn’t “what’s wrong with the app?” It’s “what’s wrong with my cluster”
What it helps us check
The app gives us a simple way to check a clusters happy deploy path.
Can ArgoCD pull the repo and sync it cleanly? Does the chart deploy? Does it go healthy on the cluster? Can a user find the app once it is exposed? Do logs show up where we expect? Are metrics being scraped?
These are small questions, but they all need to be correct for us to deploy an application we trust is healthy.
Why make it public?
Because the first thing we ask a user to deploy should not be mysterious.
The repo is public so people can inspect it, run it, and see the shape of a Kupe workload without having to decode a long explanation first.
The public repos in our kupecloud github organisation should earn their place. They should make the platform easier to understand, easier to validate, or easier to work with. hello-kupe is the smallest version of that idea.
Small on purpose
That may sound pretty obvious, but demo apps have a habit of growing. Someone adds a nicer page. Then a config option. Then a database because it would make the demo feel more real. Before long, the demo is impressive and much less useful for testing the platform.
Hello Third Party Worlds
Feel free to use any hello world app of your choosing when testing or validating Kupe Clsuters, if you’d prefer to use nginx, whoami or echoserver, that is absolutely fine. hello-kupe is just the recommended default as its what we use internally.
