> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tensor9.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Crossplane Guide

> Validate one Crossplane managed resource through Cloud Adapter before composing a platform API.

Crossplane providers continuously reconcile desired state by calling cloud APIs. Compatibility depends on the provider family, provider version, managed resource, endpoint configuration, and every operation used by reconciliation and deletion.

Do not begin with a Composition. First prove one managed resource in an isolated control plane.

## Start a local adapter

Start one service mapping before testing a composition. The bounded example uses S3 backed by Google Cloud Storage:

**1. Install or update the Tensor9 CLI**

Install the customer CLI with Homebrew, then confirm the binary is available:

```bash theme={null}
brew tap tensor9ine/tensor9
brew trust tensor9ine/tensor9
brew install tensor9
tensor9 --version
```

If `tensor9` is already installed, run `brew upgrade tensor9` instead of the install command.

**2. Authenticate with Tensor9**

To create a Tensor9 account and download an API key yourself, follow [Get a Tensor9 API key](https://docs.tensor9.com/byoc/getting-started/api-key.md).

A Tensor9 API key is required. Use the key issued during onboarding, or email [hello@tensor9.com](mailto:hello@tensor9.com) to request one for your organization. Do not share your account or key with another customer or organization.

If your secret manager has already supplied `T9_API_KEY`, skip the prompt. Otherwise, enter your key at a hidden prompt in the terminal where you will run `tensor9`:

> [tab] Bash
>
> ```bash theme={null}
> set +x
> IFS= read -r -s -p 'Tensor9 API key: ' T9_API_KEY
> printf '\n'
> export T9_API_KEY
> ```

> [tab] Zsh
>
> ```zsh theme={null}
> set +x
> IFS= read -r -s 'T9_API_KEY?Tensor9 API key: '
> printf '\n'
> export T9_API_KEY
> ```

Check that the variable is set without printing it, then verify your Tensor9 identity:

```bash theme={null}
: "${T9_API_KEY:?Set T9_API_KEY before continuing}"
tensor9 whoami
```

Confirm that the reported identity belongs to the intended customer account. Do not continue if authentication fails or the account is wrong. While `T9_API_KEY` is set, `tensor9` commands in this terminal use the key instead of any controller profile, so use a separate terminal for this work and run `unset T9_API_KEY` when you finish. Keep shell tracing disabled while using the key. Do not paste the key into commands, shell profiles, source files, screenshots or support messages.

See [Install and Authenticate](https://docs.tensor9.com/cloud-adapter-early-access/getting-started/install-and-authenticate.md) for the planned license lifecycle, entitlements and credential boundaries.

**3. Inspect the S3 to Google Cloud Storage mapping**

Ask Tensor9 to describe the exact directed service mapping used by this guide:

```bash theme={null}
tensor9 explain \
  -origin aws::1.0.0::s3 \
  -target google::1.0.0::gcs \
  -fmt Human
```

Read the supported S3 operations and Google Cloud Storage limitations before starting the process. The mapping is directional: this command describes S3 requests adapted to Google Cloud Storage, not the reverse direction.

**4. Prepare Google Cloud access**

Authenticate with Google Cloud using its standard Application Default Credentials chain. The adapter uses that identity when it calls Google Cloud Storage.

Use a dedicated test project and narrowly scoped credentials. Do not put credentials in the command line, source code, or screenshots.

**5. Start the S3 service adapter**

Run the S3 to Google Cloud Storage adapter as a foreground process:

```bash theme={null}
tensor9 adapt svc run \
  --origin aws::1.0.0::s3 \
  --backend google::1.0.0::gcs
```

Leave this terminal open. This is the current foreground launcher, not the pending Docker launcher for [local development mode](https://docs.tensor9.com/cloud-adapter-early-access/deployment/single-binary.md). It calls your actual target-cloud services; it is separate from the in-memory emulator. Acquisition and license renewal require Tensor9 authentication. Keep the endpoint local to your test.

**6. Copy the listening endpoint**

When the command reports its listening endpoint, copy that exact value into a second terminal:

```bash theme={null}
export T9_CLOUD_ADAPTER_ENDPOINT="<endpoint printed by tensor9>"
```

Keep the endpoint local to the test unless you have deliberately configured network access and authentication for another machine.

**7. Run one bounded S3 request**

Continue with this page's client or tool instructions. Point only S3 at `T9_CLOUD_ADAPTER_ENDPOINT`, then perform one operation whose Google Cloud Storage effect you can verify independently.

Check both sides: read the S3-shaped response and inspect the native object or bucket in Google Cloud Storage. A successful client response alone does not prove that the target state is correct.

**8. Stop the local adapter**

Return to the first terminal and press **Control-C**. Confirm the process exits before deleting the test object or bucket with Google Cloud's native client.

If the request failed, preserve the request ID, adapter endpoint, S3 operation name, Google Cloud request ID, and any `x-t9-explain-*` receipt headers before stopping the process.

## Choose and pin the provider

Record:

* the provider package and version;
* the managed resource kind and API version;
* the controller image digest;
* how that provider version configures a custom endpoint;
* which origin identity the controller uses;
* the deletion policy and target resource owner.

Endpoint fields differ between provider families and versions. Use the provider's published schema for the installed version rather than copying a `ProviderConfig` from another family.

## Start with one bounded resource

Choose a resource with a small lifecycle, such as one object or bucket only when its full create, observe, update, and delete operations are documented for the selected target. Give it a unique external name and no production dependencies.

Apply the provider configuration and one managed resource, then observe:

```bash theme={null}
kubectl get managed
kubectl describe <kind> <name>
kubectl get events --sort-by=.lastTimestamp
```

Record the `Ready` and `Synced` conditions, reason, message, observed generation, external name, and controller request identifiers. A healthy provider pod does not prove the managed resource reconciled.

## Verify the reconcile loop

Test each phase separately:

1. **Observe absent:** controller confirms the target resource does not exist.
2. **Create:** controller issues the documented create operation.
3. **Observe present:** controller reads back identity and late-initialized fields.
4. **No-op reconcile:** a second pass does not mutate the target.
5. **Update:** change one supported mutable field and observe convergence.
6. **Drift:** make one controlled target-side change and observe correction or reporting.
7. **Delete:** remove the managed resource and verify the configured deletion policy.

Inspect native target state after every mutation. Reconciliation retries can repeat uncertain writes, so test operation idempotency and bound controller concurrency before using shared resources.

## Composition comes later

A Composition introduces multiple managed resources, dependency ordering, patches, readiness checks, connection details, and rollback questions. Add it only after every underlying resource has its own passing lifecycle fixture and cleanup evidence.

## Common failure boundaries

| Symptom | Check |
| - | - |
| Provider unhealthy | Package pull, RBAC, controller configuration, or Kubernetes runtime. |
| Cannot connect | Adapter DNS, TLS, network policy, or endpoint schema. |
| Authentication failure | Origin-side provider identity and signing settings. |
| Permission denied downstream | Adapter target identity and target resource policy. |
| Repeated create | Observe/read fidelity, external-name mapping, or an uncertain prior write. |
| Stuck deleting | Delete operation coverage, finalizer, retention, or target dependency. |

Compare the exact operations with the service catalog and use [diagnostic response headers](https://docs.tensor9.com/cloud-adapter-early-access/debugging/response-headers.md) where the provider exposes them.


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