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

# Source Controller S3 Bucket

> Learn to use Flux CD’s Source Controller to fetch Kubernetes manifests from an S3-compatible bucket like MinIO.

In this guide, you’ll learn how to use Flux CD’s Source Controller to fetch Kubernetes manifests from an S3-compatible bucket (for example, MinIO). We assume you have a bucket named `k8s-manifests` with two subfolders, `app-A` and `app-B`, each containing its own manifests. By the end, you will:

1. Store MinIO credentials in a Kubernetes Secret
2. Register the bucket as a Flux `Bucket` source
3. Apply the `app-A` manifests via a Flux `Kustomization`

***

## Prerequisites

* A running Kubernetes cluster
* Flux CD installed (Source and Kustomize Controllers)
* A MinIO (or other S3-compatible) endpoint
* A bucket named `k8s-manifests` containing `app-A/` and `app-B/`

***

## 1. Create the MinIO Credentials Secret

Store your MinIO access key and secret key as a Kubernetes Secret in the `flux-system` namespace:

```bash theme={null}
kubectl -n flux-system create secret generic minio-crd \
  --from-literal=accesskey=minioadmin \
  --from-literal=secretkey=minioadmin
```

Expected output:

```console theme={null}
secret/minio-crd created
```

<Callout icon="lightbulb" color="#1CB2FE">
  Ensure your credentials are scoped to the least-privileged user on your S3 endpoint.
</Callout>

***

## 2. Register the Flux Bucket Source

Define a Flux `Bucket` resource that points to your S3-compatible endpoint. Replace the `--endpoint` value with your MinIO service address if different.

```bash theme={null}
flux create source bucket minio-bucket \
  --bucket-name k8s-manifests \
  --endpoint minio.minio-dev.svc.cluster.local:9000 \
  --provider generic \
  --insecure \
  --secret-ref minio-crd
```

Sample output:

```console theme={null}
► generating Bucket source
✔ Bucket source updated
⟳ waiting for Bucket source reconciliation
✔ Bucket source reconciliation completed
fetched revision: b3642f24daf09a297b6237b345a6a
```

This creates a `Bucket` named `minio-bucket` in the `flux-system` namespace, which tars and retrieves all contents under `k8s-manifests`.

<Callout icon="triangle-alert" color="#FF6B6B">
  Using `--insecure` disables TLS verification. Only use this flag in trusted environments or testing scenarios.
</Callout>

***

## 3. Apply Manifests with Flux Kustomization

Now that Flux can fetch the bucket contents, configure a Kustomization to build and apply the `app-A` manifests:

```bash theme={null}
flux create kustomization kust-app-a \
  --source Bucket/minio-bucket \
  --path "./app-A" \
  --prune=true \
  --interval=10m
```

Sample output:

```console theme={null}
► generating Kustomization
✔ Kustomization updated
⟳ waiting for Kustomization reconciliation
✔ Kustomization kust-app-a is ready
✔ applied revision b3642f24daf09a297b6237b345a6a
```

Flux will now periodically reconcile and apply the contents of `app-A` to your cluster.

***

## Summary of Resources

| Resource        | Purpose                              | Flux Command                                |
| --------------- | ------------------------------------ | ------------------------------------------- |
| Secret          | Store MinIO S3 credentials           | `kubectl create secret generic minio-crd …` |
| Bucket (Source) | Fetch objects from `k8s-manifests`   | `flux create source bucket minio-bucket …`  |
| Kustomization   | Build & apply manifests from `app-A` | `flux create kustomization kust-app-a …`    |

***

## Links and References

* [Flux Source Controller][Flux Source Controller]
* [Flux Bucket Source][Bucket Source]
* [Flux Kustomization][Kustomization]
* [Kubernetes Secrets][Kubernetes Secrets]
* [MinIO Documentation][MinIO]

[Flux Source Controller]: https://fluxcd.io/docs/components/source/

[Bucket Source]: https://fluxcd.io/docs/components/source/bucket/

[Kustomization]: https://fluxcd.io/docs/components/kustomize/kustomization/

[Kubernetes Secrets]: https://kubernetes.io/docs/concepts/configuration/secret/

[MinIO]: https://min.io/

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