---
layout: docs
page_title: GCP auth support for Vault Secrets Operator
description: >-
  Learn how GCP authentication works for Vault Secrets Operator
---

# GCP auth support for Vault Secrets Operator

The Vault Secrets Operator (VSO) supports authenticating to Vault's [GCP auth](/vault/docs/auth/gcp) method, using Google's Kubernetes Engine (GKE) workload identity.

1. Follow Google's [Use Workload Identity](https://cloud.google.com/kubernetes-engine/docs/how-to/workload-identity) guide to enable workload identity on a GKE cluster so your Kubernetes service account can impersonate a Google IAM service account. 

1. Create an appropriate authentication role in your Vault instance:

  <CodeTabs>
  <CodeBlockConfig>

  ```shell-session
  $ vault write auth/gcp/role/<VAULT_GCP_ROLE> \
      type="iam" \
      policies="default" \
      max_jwt_exp=3600 \
      bound_service_accounts="<SERVICE_ACCOUNT>@<GCP_PROJECT>.iam.gserviceaccount.com"
  ```

  </CodeBlockConfig>
  <CodeBlockConfig>

  ```hcl
  resource "vault_gcp_auth_backend_role" "gcp_role" {
    backend                = "auth/gcp"
    role                   = <VAULT_GCP_ROLE>
    type                   = "iam"
    token_policies         = "default"
    max_jwt_exp            = 3600
    bound_service_accounts = [
      "<SERVICE_ACCOUNT>@<GCP_PROJECT>.iam.gserviceaccount.com",
    ]
  }
  ```

  </CodeBlockConfig>
  </CodeTabs>

  <Note>

    `max_jwt_exp` needs to be greater than or equal to 1 hour (3600)
  
  </Note>

1. Create the corresponding authentication object for VSO:

  ```yaml
  apiVersion: secrets.hashicorp.com/v1beta1
  kind: VaultAuth
  metadata:
    name: vaultauth-gcp-example
    namespace: <K8S_NAMESPACE>
  spec:
    vaultConnectionRef: <VAULT_CONNECTION_NAME>
    mount: gcp
    method: gcp
    gcp:
      role: <VAULT_GCP_ROLE>
      workloadIdentityServiceAccount: <K8S_SERVICE_ACCOUNT>
  ```

<Tip title="Terraform has workload identity support">

  If you use Terraform to manage your GKE cluster, the
  [GKE module](https://registry.terraform.io/modules/terraform-google-modules/kubernetes-engine/google/latest)
  includes workload identity support through the
  [workload identity submodule](https://registry.terraform.io/modules/terraform-google-modules/kubernetes-engine/google/latest/submodules/workload-identity).

</Tip>

# API

See the full list of GCP VaultAuth options on the [VSO API page](/vault/docs/platform/k8s/vso/api-reference#vaultauthconfiggcp).
