demo-xfn-claim-com

demo-xfn-claim-com

This repo contains an end to end demo for Crossplane Composition Functions that utilizes the functionality to expose status and events up to the level of a claim.

The demo will create two LandingZone resources that will fail, but demonstrate how the UX has greatly improved. The first LandingZone will use the classic/old UX and the user will never see any useful error information to determine root cause.

The second LandingZone uses the modern Crossplane (v1.17+) UX and the user will see an obvious root cause and how to fix it surfaced up to the claim.

Development

Instructions for local development of this function can be found in DEVELOPMENT.md.

Pre-Requisites

Create a Kubernetes cluster, e.g. with kind:

kind create cluster

Install Crossplane from the stable release channel, e.g.:

helm repo add crossplane-stable https://charts.crossplane.io/stable
helm repo update
helm install crossplane --namespace crossplane-system --create-namespace crossplane-stable/crossplane

Setup

Install the demo-xfn-claim-com Function:

kubectl apply -f example/functions.yaml
kubectl apply -f example/providers.yaml

Wait for them to become installed/healthy:

kubectl get pkg

Define your LandingZone abstraction by creating a CompositeResourceDefinition (XRD) that defines the API and a Composition that defines the implementation:

kubectl apply -f example/xrd.yaml
kubectl apply -f example/composition-classic.yaml
kubectl apply -f example/composition-modern.yaml

Demo

Create a claim for this LandingZone abstraction, using the classic/old UX:

kubectl apply -f example/claim-classic.yaml

We expect this claim to never become ready/healthy, but because it's using the classic UX, there won't be any good information on why or how to fix it.

kubectl get landingzone.xp-demo.crossplane.io/landing-zone-dev
kubectl get landingzone.xp-demo.crossplane.io/landing-zone-dev -ojson | jq '.status'
kubectl describe landingzone.xp-demo.crossplane.io/landing-zone-dev

Create another LandingZone claim that uses the modern UX this time:

kubectl apply -f example/claim-modern.yaml

We also expect this to fail, but this time it will be much more clear what the issue is because the function is communicating specific status and events back to the claim.

kubectl get landingzone.xp-demo.crossplane.io/landing-zone-prod
kubectl get landingzone.xp-demo.crossplane.io/landing-zone-prod -ojson | jq '.status'
kubectl describe landingzone.xp-demo.crossplane.io/landing-zone-prod

Voila! The root cause of this claim's failure is now clear and actionable because the function has communicated it up to the claim as a status condition and an event. Now we know how to fix this error by updating the claim's .spec.tier field to a valid value, such as standard or critical.

Make this edit, then apply the claim again:

kubectl apply -f example/claim-modern.yaml

We have fixed the error and we expect the claim to get to ready/healthy soon.

kubectl get landingzone.xp-demo.crossplane.io/landing-zone-prod
kubectl get landingzone.xp-demo.crossplane.io/landing-zone-prod -ojson | jq '.status'

Clean up

Clean up all the objects:

kubectl delete -f example/claim-classic.yaml
kubectl delete -f example/claim-modern.yaml

Delete the compositions and XRD:

kubectl delete -f example/xrd.yaml
kubectl delete -f example/composition-classic.yaml
kubectl delete -f example/composition-modern.yaml

Uninstall the functions/providers:

kubectl delete -f example/functions.yaml
kubectl delete -f example/providers.yaml