![HCP Vault](../pictures/diagrams-provider-vault.png)

## Hashicorp Vault

External Secrets Operator integrates with [HashiCorp Vault](https://www.vaultproject.io/) for secret management.

The [KV Secrets Engine](https://www.vaultproject.io/docs/secrets/kv) is the only
one supported by this provider. For other secrets engines, please refer to the
[Vault Generator](../api/generator/vault.md).

### Example

First, create a SecretStore with a vault backend. For the sake of simplicity we'll use a static token `root`:

```yaml
apiVersion: external-secrets.io/v1beta1
kind: SecretStore
metadata:
  name: vault-backend
spec:
  provider:
    vault:
      server: "http://my.vault.server:8200"
      path: "secret"
      # Version is the Vault KV secret engine version.
      # This can be either "v1" or "v2", defaults to "v2"
      version: "v2"
      auth:
        # points to a secret that contains a vault token
        # https://www.vaultproject.io/docs/auth/token
        tokenSecretRef:
          name: "vault-token"
          key: "token"
---
apiVersion: v1
kind: Secret
metadata:
  name: vault-token
data:
  token: cm9vdA== # "root"
```
**NOTE:** In case of a `ClusterSecretStore`, Be sure to provide `namespace` for `tokenSecretRef` with the namespace of the secret that we just created.

Then create a simple k/v pair at path `secret/foo`:

```
vault kv put secret/foo my-value=s3cr3t
```

Can check kv version using following and check for `Options` column, it should indicate [version:2]:

```
vault secrets list -detailed
```

If you are using version: 1, just remember to update your SecretStore manifest appropriately

Now create a ExternalSecret that uses the above SecretStore:

```yaml
apiVersion: external-secrets.io/v1beta1
kind: ExternalSecret
metadata:
  name: vault-example
spec:
  refreshInterval: "15s"
  secretStoreRef:
    name: vault-backend
    kind: SecretStore
  target:
    name: example-sync
  data:
  - secretKey: foobar
    remoteRef:
      key: foo
      property: my-value

  # metadataPolicy to fetch all the labels in JSON format
  - secretKey: tags
    remoteRef:
      metadataPolicy: Fetch 
      key: foo

  # metadataPolicy to fetch a specific label (dev) from the source secret
  - secretKey: developer
    remoteRef:
      metadataPolicy: Fetch 
      key: foo
      property: dev

---
# will create a secret with:
kind: Secret
metadata:
  name: example-sync
data:
  foobar: czNjcjN0
```

Keep in mind that fetching the labels with `metadataPolicy: Fetch` only works with KV sercrets engine version v2.

#### Fetching Raw Values

You can fetch all key/value pairs for a given path If you leave the `remoteRef.property` empty. This returns the json-encoded secret value for that path.

```yaml
apiVersion: external-secrets.io/v1beta1
kind: ExternalSecret
metadata:
  name: vault-example
spec:
  # ...
  data:
  - secretKey: foobar
    remoteRef:
      key: /dev/package.json
```

#### Nested Values

Vault supports nested key/value pairs. You can specify a [gjson](https://github.com/tidwall/gjson) expression at `remoteRef.property` to get a nested value.

Given the following secret - assume its path is `/dev/config`:
```json
{
  "foo": {
    "nested": {
      "bar": "mysecret"
    }
  }
}
```

You can set the `remoteRef.property` to point to the nested key using a [gjson](https://github.com/tidwall/gjson) expression.
```yaml
apiVersion: external-secrets.io/v1beta1
kind: ExternalSecret
metadata:
  name: vault-example
spec:
  # ...
  data:
  - secretKey: foobar
    remoteRef:
      key: /dev/config
      property: foo.nested.bar
---
# creates a secret with:
# foobar=mysecret
```

If you would set the `remoteRef.property` to just `foo` then you would get the json-encoded value of that property: `{"nested":{"bar":"mysecret"}}`.

#### Multiple nested Values

You can extract multiple keys from a nested secret using `dataFrom`.

Given the following secret - assume its path is `/dev/config`:
```json
{
  "foo": {
    "nested": {
      "bar": "mysecret",
      "baz": "bang"
    }
  }
}
```

You can set the `remoteRef.property` to point to the nested key using a [gjson](https://github.com/tidwall/gjson) expression.
```yaml
apiVersion: external-secrets.io/v1beta1
kind: ExternalSecret
metadata:
  name: vault-example
spec:
  # ...
  dataFrom:
  - extract:
      key: /dev/config
      property: foo.nested
```

That results in a secret with these values:
```
bar=mysecret
baz=bang
```

#### Getting multiple secrets

You can extract multiple secrets from Hashicorp vault by using `dataFrom.Find`

Currently, `dataFrom.Find` allows users to fetch secret names that match a given regexp pattern, or fetch secrets whose `custom_metadata` tags match a predefined set.


!!! warning
    The way hashicorp Vault currently allows LIST operations is through the existence of a secret metadata. If you delete the secret, you will also need to delete the secret's metadata or this will currently make Find operations fail.

Given the following secret - assume its path is `/dev/config`:
```json
{
  "foo": {
    "nested": {
      "bar": "mysecret",
      "baz": "bang"
    }
  }
}
```

Also consider the following secret has the following `custom_metadata`:
```json
{
  "environment": "dev",
  "component": "app-1"
}
```

It is possible to find this secret by all the following possibilities:
```yaml
apiVersion: external-secrets.io/v1beta1
kind: ExternalSecret
metadata:
  name: vault-example
spec:
  # ...
  dataFrom:
  - find: #will return every secret with 'dev' in it (including paths)
      name:
        regexp: dev
  - find: #will return every secret matching environment:dev tags from dev/ folder and beyond
      tags:
        environment: dev
```
will generate a secret with:
```json
{
  "dev_config":"{\"foo\":{\"nested\":{\"bar\":\"mysecret\",\"baz\":\"bang\"}}}"
}
```

Currently, `Find` operations are recursive throughout a given vault folder, starting on `provider.Path` definition. It is recommended to narrow down the scope of search by setting a `find.path` variable. This is also useful to automatically reduce the resulting secret key names:
```yaml
apiVersion: external-secrets.io/v1beta1
kind: ExternalSecret
metadata:
  name: vault-example
spec:
  # ...
  dataFrom:
  - find: #will return every secret from dev/ folder
      path: dev
      name:
        regexp: ".*"
  - find: #will return every secret matching environment:dev tags from dev/ folder
      path: dev
      tags:
        environment: dev
```
Will generate a secret with:
```json
{
  "config":"{\"foo\": {\"nested\": {\"bar\": \"mysecret\",\"baz\": \"bang\"}}}"
}

```
### Authentication

We support five different modes for authentication:
[token-based](https://www.vaultproject.io/docs/auth/token),
[appRole](https://www.vaultproject.io/docs/auth/approle),
[kubernetes-native](https://www.vaultproject.io/docs/auth/kubernetes),
[ldap](https://www.vaultproject.io/docs/auth/ldap),
[jwt/oidc](https://www.vaultproject.io/docs/auth/jwt) and
[awsAuth](https://developer.hashicorp.com/vault/docs/auth/aws), each one comes with it's own
trade-offs. Depending on the authentication method you need to adapt your environment.

#### Token-based authentication

A static token is stored in a `Kind=Secret` and is used to authenticate with vault.

```yaml
{% include 'vault-token-store.yaml' %}
```
**NOTE:** In case of a `ClusterSecretStore`, Be sure to provide `namespace` in `tokenSecretRef` with the namespace where the secret resides.

#### AppRole authentication example

[AppRole authentication](https://www.vaultproject.io/docs/auth/approle) reads the secret id from a
`Kind=Secret` and uses the specified `roleId` to aquire a temporary token to fetch secrets.

```yaml
{% include 'vault-approle-store.yaml' %}
```
**NOTE:** In case of a `ClusterSecretStore`, Be sure to provide `namespace` in `secretRef` with the namespace where the secret resides.

#### Kubernetes authentication

[Kubernetes-native authentication](https://www.vaultproject.io/docs/auth/kubernetes) has three
options of obtaining credentials for vault:

1.  by using a service account jwt referenced in `serviceAccountRef`
2.  by using the jwt from a `Kind=Secret` referenced by the `secretRef`
3.  by using transient credentials from the mounted service account token within the
    external-secrets operator

```yaml
{% include 'vault-kubernetes-store.yaml' %}
```
**NOTE:** In case of a `ClusterSecretStore`, Be sure to provide `namespace` in `serviceAccountRef` or in `secretRef`, if used.

#### LDAP authentication

[LDAP authentication](https://www.vaultproject.io/docs/auth/ldap) uses
username/password pair to get an access token. Username is stored directly in
a `Kind=SecretStore` or `Kind=ClusterSecretStore` resource, password is stored
in a `Kind=Secret` referenced by the `secretRef`.

```yaml
{% include 'vault-ldap-store.yaml' %}
```
**NOTE:** In case of a `ClusterSecretStore`, Be sure to provide `namespace` in `secretRef` with the namespace where the secret resides.

#### JWT/OIDC authentication

[JWT/OIDC](https://www.vaultproject.io/docs/auth/jwt) uses either a
[JWT](https://jwt.io/) token stored in a `Kind=Secret` and referenced by the
`secretRef` or a temporary Kubernetes service account token retrieved via the `TokenRequest` API. Optionally a `role` field can be defined in a `Kind=SecretStore`
or `Kind=ClusterSecretStore` resource.

```yaml
{% include 'vault-jwt-store.yaml' %}
```
**NOTE:** In case of a `ClusterSecretStore`, Be sure to provide `namespace` in `secretRef` with the namespace where the secret resides.

#### AWS IAM authentication

[AWS IAM](https://developer.hashicorp.com/vault/docs/auth/aws) uses either a
set of AWS Programmatic access credentials stored in a `Kind=Secret` and referenced by the
`secretRef` or by getting the authentication token from an [IRSA](https://docs.aws.amazon.com/eks/latest/userguide/iam-roles-for-service-accounts.html) enabled service account

### Access Key ID & Secret Access Key
You can store Access Key ID & Secret Access Key in a `Kind=Secret` and reference it from a SecretStore.

```yaml
{% include 'vault-iam-store-static-creds.yaml' %}
```

**NOTE:** In case of a `ClusterSecretStore`, Be sure to provide `namespace` in `accessKeyIDSecretRef`, `secretAccessKeySecretRef` with the namespaces where the secrets reside.

### EKS Service Account credentials

This feature lets you use short-lived service account tokens to authenticate with AWS.
You must have [Service Account Volume Projection](https://kubernetes.io/docs/tasks/configure-pod-container/configure-service-account/#service-account-token-volume-projection) enabled - it is by default on EKS. See [EKS guide](https://docs.aws.amazon.com/eks/latest/userguide/iam-roles-for-service-accounts-technical-overview.html) on how to set up IAM roles for service accounts.

The big advantage of this approach is that ESO runs without any credentials.

```yaml
{% include 'vault-iam-store-sa.yaml' %}
```

Reference the service account from above in the Secret Store:

```yaml
{% include 'vault-iam-store.yaml' %}
```
### Controller's Pod Identity

This is basicially a zero-configuration authentication approach that inherits the credentials from the controller's pod identity

This approach assumes that appropriate IRSA setup is done controller's pod (i.e. IRSA enabled IAM role is created appropriately and controller's service account is annotated appropriately with the annotation "eks.amazonaws.com/role-arn" to enable IRSA)

```yaml
{% include 'vault-iam-store-controller-pod-identity.yaml' %}
```

**NOTE:** In case of a `ClusterSecretStore`, Be sure to provide `namespace` for `serviceAccountRef` with the namespace where the service account resides.

```yaml
{% include 'vault-jwt-store.yaml' %}
```
**NOTE:** In case of a `ClusterSecretStore`, Be sure to provide `namespace` in `secretRef` with the namespace where the secret resides.

### PushSecret
Vault supports PushSecret features which allow you to sync a given kubernetes secret key into a hashicorp vault secret. In order to do so, it is expected that the secret key is a valid JSON object.

In order to use PushSecret, you need to give `create`, `read` and `update` permissions to the path where you want to push secrets to for both `data` and `metadata` of the secret. Use it with care!

Here is an example on how to set it up:
```yaml
{% include 'vault-pushsecret.yaml' %}
```

### Vault Enterprise

#### Eventual Consistency and Performance Standby Nodes

When using Vault Enterprise with [performance standby nodes](https://www.vaultproject.io/docs/enterprise/consistency#performance-standby-nodes),
any follower can handle read requests immediately after the provider has
authenticated. Since Vault becomes eventually consistent in this mode, these
requests can fail if the login has not yet propagated to each server's local
state.

Below are two different solutions to this scenario. You'll need to review them
and pick the best fit for your environment and Vault configuration.

#### Vault Namespaces

[Vault namespaces](https://www.vaultproject.io/docs/enterprise/namespaces) are an enterprise feature that support multi-tenancy. You can specify a vault namespace using the `namespace` property when you define a SecretStore:

```yaml
apiVersion: external-secrets.io/v1beta1
kind: SecretStore
metadata:
  name: vault-backend
spec:
  provider:
    vault:
      server: "http://my.vault.server:8200"
      # See https://www.vaultproject.io/docs/enterprise/namespaces
      namespace: "ns1"
      path: "secret"
      version: "v2"
      auth:
        # ...
```

#### Read Your Writes

Vault 1.10.0 and later encodes information in the token to detect the case
when a server is behind. If a Vault server does not have information about
the provided token, [Vault returns a 412 error](https://www.vaultproject.io/docs/faq/ssct#q-is-there-anything-else-i-need-to-consider-to-achieve-consistency-besides-upgrading-to-vault-1-10)
so clients know to retry.

A method supported in versions Vault 1.7 and later is to utilize the
`X-Vault-Index` header returned on all write requests (including logins).
Passing this header back on subsequent requests instructs the Vault client
to retry the request until the server has an index greater than or equal
to that returned with the last write. Obviously though, this has a performance
hit because the read is blocked until the follower's local state has caught up.

#### Forward Inconsistent

Vault also supports proxying inconsistent requests to the current cluster leader
for immediate read-after-write consistency.

Vault 1.10.0 and later [support a replication configuration](https://www.vaultproject.io/docs/faq/ssct#q-is-there-a-new-configuration-that-this-feature-introduces) that detects when forwarding should occur and does it transparently to the client.

In Vault 1.7 forwarding can be achieved by setting the `X-Vault-Inconsistent`
header to `forward-active-node`. By default, this behavior is disabled and must
be explicitly enabled in the server's [replication configuration](https://www.vaultproject.io/docs/configuration/replication#allow_forwarding_via_header).
