# 03 — Crossplane CRD discovery

## What you'll do

Understand how RunWhen's Kubernetes indexer discovers **custom
resources** — specifically the Crossplane GCP Bucket CRD — driven entirely
by what your generation rules ask for.

## Step 1 — Confirm the CRD exists

```bash
kubectl api-resources | grep storage.gcp.upbound.io
```

Expected output (trimmed):

```
buckets                                          storage.gcp.upbound.io/v1beta1               false        Bucket
bucketiammembers                                 storage.gcp.upbound.io/v1beta1               false        BucketIAMMember
hmackeys                                         storage.gcp.upbound.io/v1beta1               false        HMACKey
```

Three things to note:

1. **`buckets`** — this is the *plural resource name*. It is what you
   put in the generation rule, not the singular `Bucket`.
2. **`storage.gcp.upbound.io/v1beta1`** — the API group and preferred
   version.
3. **`false` in the "NAMESPACED" column** — Crossplane managed resources
   are **cluster-scoped**. This is why our generation rule uses
   `qualifiers: ["resource", "cluster"]` and not `namespace`.

Screenshot placeholder: `images/03-kubectl-api-resources.png` — output of
the above command.

## Step 2 — Confirm buckets exist to discover

```bash
kubectl get buckets.storage.gcp.upbound.io -o wide
```

Sample output on the airgap cluster:

```
NAME                                                  READY   SYNCED   EXTERNAL-NAME
runwhen-nonprod-shared-litellm-logging                True    True     runwhen-nonprod-shared-litellm-logging
runwhen-nonprod-shared-loki                           True    True     runwhen-nonprod-shared-loki
runwhen-nonprod-shared-mimir                          True    True     runwhen-nonprod-shared-mimir
runwhen-nonprod-shared-tempo                          True    True     runwhen-nonprod-shared-tempo
```

Screenshot placeholder: `images/03-kubectl-buckets.png`.

## Step 3 — Look at the `.status.conditions[]` we care about

This is what the SLI and TaskSet will read. Pick any bucket and inspect it:

```bash
kubectl get buckets.storage.gcp.upbound.io <name> -o json | jq .status.conditions
```

Expected shape:

```json
[
  {
    "lastTransitionTime": "2025-11-14T10:15:11Z",
    "reason": "Available",
    "status": "True",
    "type": "Ready"
  },
  {
    "lastTransitionTime": "2025-11-14T10:15:10Z",
    "reason": "ReconcileSuccess",
    "status": "True",
    "type": "Synced"
  }
]
```

Every Crossplane managed resource carries these two conditions:

- **`Ready`** — the external resource (the actual GCS bucket in GCP) exists
  and is available. When `Ready=False`, something in GCP is wrong (missing
  IAM, quota, deleted out-of-band, etc.).
- **`Synced`** — the last reconcile between the Crossplane spec and the
  provider succeeded. When `Synced=False`, Crossplane could not talk to
  the provider or hit a validation error.

Our SLI computes `(#True conditions) / (#total conditions)`, so a healthy
bucket returns `1.0` and any single failing condition drops it to `0.5`
or `0.0`.

## Step 4 — Understand how workspace-builder gets there

RunWhen Local's Kubernetes indexer performs **selective discovery**: it
only lists custom resource types that appear in loaded generation rules.
That's why simply declaring `buckets.storage.gcp.upbound.io/v1beta1` in
our rule is enough — no extra `customResourceTypes:` list in
`workspaceInfo.yaml`.

The parsing (in
[`runwhen-local/src/indexers/kubetypes.py`](https://github.com/runwhen-contrib/runwhen-local/blob/main/src/indexers/kubetypes.py))
takes the string `plural.group/version` and splits it into
`(plural='buckets', group='storage.gcp.upbound.io', version='v1beta1')`.
It then calls `CustomObjectsApi.list_cluster_custom_object(...)`.

You can also specify custom resources with a **dict** form, useful when
you need to be explicit about a particular version:

```yaml
resourceTypes:
  - platform: kubernetes
    resourceType: custom
    kind: buckets              # plural, NOT PascalCase
    group: storage.gcp.upbound.io
    version: v1beta1
```

## Common pitfalls

- **Wrong plural** — the biggest source of "nothing gets discovered". Always
  copy the plural from `kubectl api-resources`, never guess it from the
  `Kind`.
- **Version omission** — leaving off `/v1beta1` uses the API server's
  *preferred* version. Usually fine but pin it explicitly if you rely on
  a specific schema.
- **RBAC** — workspace-builder needs `get`/`list`/`watch` on the CRD. The
  airgap runner already binds `workspace-builder` SA to `view` at the
  cluster scope via
  [`rbac/workspace-builder-view-rbac.yaml`](https://github.com/runwhen/infra-flux-nonprod-shared/blob/main/apps/runwhen-env/airgap/rbac/workspace-builder-view-rbac.yaml),
  which covers CRDs installed after the binding was created.
- **Namespace scope** — some CRDs are namespaced. If you had chosen a
  namespaced CRD you would need to include the CRD's namespaces in your
  `cloudConfig.kubernetes.namespaces` list *or* leave that list empty.

## Next

Continue to [04 — Generation rule walkthrough](04-generation-rule-walkthrough.md).