Secrets Store CSI driver for Kubernetes secrets - Integrates secrets stores with Kubernetes via a Container Storage Interface (CSI) volume.

The Secrets Store CSI driver secrets-store.csi.k8s.com allows Kubernetes to mount multiple secrets, keys, and certs stored in enterprise-grade external secrets stores into their pods as a volume. Once the Volume is attached, the data in it is mounted into the container's file system.

• Mounts secrets/keys/certs to pod using a CSI volume
• Supports CSI Inline volume (Kubernetes version v1.15+)
• Supports mounting multiple secrets store objects as a single volume
• Supports pod identity to restrict access with specific identities (WIP)
• Supports multiple secrets stores as providers

• How It Works
• Demo
• Usage
• Providers
  • Azure Key Vault Provider
  • HashiCorp Vault Provider
  • Adding a New Provider via the Provider Interface
• Testing
  • Unit Tests
  • End-to-end Tests
• Known Issues and Workarounds
• Contributing

The diagram below illustrates how Secrets Store CSI Volume works.

• Deploy a Kubernetes cluster v1.15.0-alpha.2+ and make sure it's reachable. The CSI Inline Volume feature was introduced in v1.15.0.
• Update the API Server manifest to append the following feature gate:

--feature-gates=CSIInlineVolume=true

• Update Kubelet manifest on each node to append the CSIInlineVolume feature gate:

--feature-gates=CSIInlineVolume=true

Make sure you already have helm CLI installed.

$ cd charts/secrets-store-csi-driver
$ helm install . -n csi-secrets-store --namespace dev

Expected output:

NAME:   csi-secrets-store
LAST DEPLOYED: Mon Jan  7 18:39:41 2019
NAMESPACE: dev
STATUS: DEPLOYED

RESOURCES:
==> v1/RoleBinding
NAME                   AGE
csi-attacher-role-cfg  1s

==> v1/DaemonSet
csi-secrets-store-secrets-store-csi-driver  1s

==> v1/StatefulSet
csi-secrets-store-attacher  1s

==> v1/Pod(related)

NAME                                    READY  STATUS             RESTARTS  AGE
csi-secrets-store-attacher-0                 0/1    ContainerCreating  0         1s
csi-secrets-store-secrets-store-csi-driver-9crwj  0/2    ContainerCreating  0         1s
csi-secrets-store-secrets-store-csi-driver-pcbtg  0/2    ContainerCreating  0         1s

==> v1beta1/CustomResourceDefinition

NAME                           AGE
csidrivers.csi.storage.k8s.io  1s

==> v1/ClusterRole
driver-registrar-runner   1s
external-attacher-runner  1s

==> v1/ClusterRoleBinding
csi-driver-registrar-role  1s
csi-attacher-role          1s

==> v1/Role
external-attacher-cfg  1s

==> v1/ServiceAccount
csi-driver-registrar  1s
csi-attacher          1s

==> v1/Service
csi-secrets-store-attacher  1s


NOTES:
The Secrets Store CSI Driver is getting deployed to your cluster.

To verify that Secrets Store CSI Driver has started, run:

  kubectl --namespace=dev get pods -l "app=secrets-store-csi-driver"

Now you can follow these steps https://github.com/deislabs/secrets-store-csi-driver#use-the-secrets-store-csi-driver
to create a PersistentVolume, a static PVC, and a deployment using the PVC.

$ kubectl --namespace=dev get pods -l "app=secrets-store-csi-driver"
NAME                                     READY     STATUS    RESTARTS   AGE
csi-secrets-store-attacher-0                  1/1       Running   0          43s
csi-secrets-store-secrets-store-csi-driver-9crwj   2/2       Running   0          43s
csi-secrets-store-secrets-store-csi-driver-pcbtg   2/2       Running   0          43s

kubectl apply -f deploy/crd-csi-driver-registry.yaml
kubectl apply -f deploy/rbac-csi-driver-registrar.yaml
kubectl apply -f deploy/rbac-csi-attacher.yaml
kubectl apply -f deploy/csi-secrets-store-attacher.yaml
kubectl apply -f deploy/secrets-store-csi-driver.yaml
kubectl apply -f deploy/csidriver.yaml

kubectl get po

csi-secrets-store-2c5ln         2/2     Running   0          4m
csi-secrets-store-attacher-0    1/1     Running   0          6m
csi-secrets-store-qp9r8         2/2     Running   0          4m
csi-secrets-store-zrjt2         2/2     Running   0          4m

1. Select a provider from the list of supported providers

2. Update deployment of resource to add inline volume using the Secrets Store CSI driver, follow specific deployment steps for the selected provider to update all the required fields in this deployment yaml.

volumes:
  - name: secrets-store-inline
    csi:
      driver: secrets-store.csi.k8s.com
      readOnly: true
      volumeAttributes:
        providerName: "azure"
        usePodIdentity: "false"         # [OPTIONAL] if not provided, will default to "false"
        keyvaultName: ""                # the name of the KeyVault
        objects:  |
          array:
            - |
              objectName: secret1
              objectType: secret        # object types: secret, key or cert
              objectVersion: ""         # [OPTIONAL] object versions, default to latest if empty
            - |
              objectName: key1
              objectType: key
              objectVersion: ""
        resourceGroup: ""               # the resource group of the KeyVault
        subscriptionId: ""              # the subscription ID of the KeyVault
        tenantId: ""                    # the tenant ID of the KeyVault
      nodePublishSecretRef:
        name: secrets-store-creds

3. Deploy your resource with the inline CSI volume

kubectl apply -f deploy/example/nginx-pod-secrets-store-inline-volume.yaml

Validate the pod has access to the secret from your secrets store instance:

kubectl exec -it nginx-secrets-store-inline ls /mnt/secrets-store/
testsecret

csi:
  driver: secrets-store.csi.k8s.com
  readOnly: true
  volumeHandle: kv
  volumeAttributes:
    providerName: "azure"
    ...

kubectl apply -f deploy/example/pv-secrets-store-csi.yaml

kubectl apply -f deploy/example/pvc-secrets-store-csi-static.yaml

volumeMounts:
  - name: secrets-store01
    mountPath: "/mnt/secrets-store"

kind: Pod
apiVersion: v1
metadata:
  name: nginx-secrets-store
spec:
  containers:
  - image: nginx
    name: nginx-secrets-store
    volumeMounts:
    - name: secrets-store01
      mountPath: "/mnt/secrets-store"
  volumes:
  - name: secrets-store01
    persistentVolumeClaim:
      claimName: pvc-secrets-store

kubectl apply -f deploy/example/nginx-pod-secrets-store.yaml

kubectl exec -it nginx-secrets-store ls /mnt/secrets-store/
testsecret

This project features a pluggable provider interface developers can implement that defines the actions of the Secrets Store CSI driver.

This enables on-demand retrieval of sensitive objects storied an enterprise-grade external secrets store into Kubernetes while continue to manage these objects outside of Kubernetes.

Each provider may have its own required properties.

Providers must provide the following functionality to be considered a supported integration.

1. Provides the backend plumbing necessary to access objects from the external secrets store.
2. Conforms to the current API provided by the Secrets Store CSI Driver.
3. Does not have access to the Kubernetes APIs and has a well-defined callback mechanism to mount objects to a target path.

• Supported Providers:
  • Azure Key Vault Provider
  • HashiCorp Vault Provider

Create a new directory for your provider under providers and implement the following interface. Then add your provider in providers/register/provider_<provider_name>.go. Make sure to add a build tag so that your provider can be excluded from being built. The format for this build tag should be no_<provider_name>_provider.

// Provider contains the methods required to implement a Secrets Store CSI Driver provider.
type Provider interface {
    // MountSecretsStoreObjectContent mounts content of the secrets store object to target path
    MountSecretsStoreObjectContent(ctx context.Context, attrib map[string]string, secrets map[string]string, targetPath string, permission os.FileMode) error
}

Run unit tests locally with make test.

WIP

WIP