Demo: Crossplane Devex Improvements

This demo walks through a typical platform builder experience using previous versions of Crossplane. It demonstrates that building your platform was somewhat challenging and it could be difficult to understand where errors may be lurking.

Then the demo uses the new convert command to migrate to a functions based composition and uses new local development tooling with a great experience to rapidly find issues in your platform and get to a functional successful state.

Pre-reqs

Create a new control plane

kind create cluster
helm install crossplane crossplane-stable/crossplane --namespace crossplane-system --create-namespace --set args='{"--enable-composition-webhook-schema-validation=false"}'

Install Providers and config

kubectl apply -f provider.yaml

# first generate GCP creds file with https://docs.crossplane.io/latest/getting-started/provider-gcp/#generate-a-gcp-service-account-json-file
kubectl create secret generic gcp-secret -n crossplane-system --from-file=creds=./gcp-credentials.json
kubectl apply -f providerconfig.yaml

Deploy platform (the hard way)

Using an older (and more challenging) experience of Crossplane, you would need to test the platform you're building by deploying to a live control plane and provisioning real world resources. That's slow, expensive, and who really has the patience for that?

kubectl apply -f pre/definition.yaml
kubectl apply -f pre/composition.yaml
kubectl get xrd

Now we can test the platform we've built by provisioning an AcmeDatabase resource:

kubectl apply -f pre/claim.yaml

Let's examine the database we just requested:

kubectl get claim
kubectl get composite
kubectl get managed

Let's check the database settings in GCP:

kubectl get DatabaseInstance -l crossplane.io/claim-name=acme-db-prod -o json | jq '.items[0].spec.forProvider.settings'

Hmm, wait a minute - we asked for a 100GB database, right? But we're getting one that is only 10GB. What could possibly be going wrong here?

kubectl get acmedatabase -o json | jq '.items[0].spec.storageGB'

Creating real resources and waiting for them is a long tough cycle to debug. Isn't there a better way to iterate on my platform instead of provisioning live resources and seeing what happens?

Platform iteration made easier with Functions & DevEx

Let's migrate to the new way of building platforms in Crossplane that has a much improved platform builder experience!

The convert command will migrate our classic patch & transform Composition to one that has a Functions pipeline. Note that most of the content doesn't actually change, because while we're now using functions, we are using function-patch-and-transform that has an almost identical API as classic P&T.

crossplane beta convert pipeline-composition pre/composition.yaml -o post/composition-func.yaml

Now we can build, test, iterate, and verify our platform all on our local laptop! No need to provision live resources in the cloud on a live control plane, we can get instant feedback as we make changes!

crossplane beta render post/xr.yaml post/composition-func.yaml post/functions.yaml

Aha! The issue is we're patching to the discSize field, which is a typo from the correct diskSize field. We see this immediately when we run the local render of our Composition:

   settings:
    - discSize: 100
      diskSize: 10

Let's fix this minor (but majorly pesky) bug and try again:

crossplane beta render post/xr.yaml post/composition-func.yaml post/functions.yaml

To be even more confident that we're building a correct composition, let's also run validate to verify all the generated resources are compliant with their schemas:

crossplane beta render post/xr.yaml post/composition-func.yaml post/functions.yaml -x | crossplane beta validate post/extensions.yaml --cache-dir="${HOME}/.crossplane/cache" -

Clean up

When we're done, make sure to clean up any cloud resources we created:

kubectl delete -f pre/claim.yaml
kubectl get managed
kubectl delete -f pre/definition.yaml
kubectl delete -f pre/composition.yaml
kubectl get xrd
kind delete cluster