GCP Secret Manager

The current version of Kong Gateway’s implementation supports configuring GCP Secret Manager in two ways:

• Environment variables
• Workload Identity

Configure GCP Secret Manager

To configure GCP Secret Manager, the GCP_SERVICE_ACCOUNT environment variable must be set to the JSON document referring to the credentials for your service account:

export GCP_SERVICE_ACCOUNT=$(cat gcp-project-c61f2411f321.json)

Kong Gateway uses the key to automatically authenticate with the GCP API and grant you access.

To use GCP Secret Manager with Workload Identity on a GKE cluster, update your pod spec so that the service account is attached to the pod. For configuration information, read the Workload Identity configuration documentation.

Notes:

• With Workload Identity, setting the GCP_SERVICE_ACCOUNT isn’t necessary.
• When using GCP Vault as a backend, make sure you have configured system as part of the lua_ssl_trusted_certificate configuration directive so that the SSL certificates used by the official GCP API can be trusted by Kong.

Examples

To use a GCP Secret Manager secret with the name secret-name, create a JSON object in GCP that contains one or more properties:

{
  "foo": "bar",
  "snip": "snap"
}

You can now reference the secret’s individual resources like this:

{vault://gcp/secret-name/foo?project_id=project_id}
{vault://gcp/secret-name/snip?project_id=project_id}

Note that both the provider (gcp) as well as the GCP project ID (project_id) need to be specified. You can configure the project ID with an environment variable before starting Kong Gateway:

export KONG_VAULT_GCP_PROJECT_ID=project_id

Then you don’t need to repeat it in references:

{vault://gcp/secret-name/foo}
{vault://gcp/secret-name/snip}

Configuration via vaults entity

Once the database is initialized, a Vault entity can be created that encapsulates the provider and the GCP project ID:

Admin API

Declarative configuration

curl -i -X PUT http://HOSTNAME:8001/vaults/gcp-sm-vault \
  --data name=gcp \
  --data description="Storing secrets in GCP Secret Manager" \
  --data config.project_id="project_id"

Result:

{
    "config": {
        "project_id": "project_id"
    },
    "created_at": 1657874961,
    "description": "Storing secrets in GCP Secret Manager",
    "id": "90e200be-cf84-4ce9-a1d6-a41c75c79f31",
    "name": "gcp",
    "prefix": "gcp-sm-vault",
    "tags": null,
    "updated_at": 1657874961
}

Secrets management is supported in decK 1.16 and later.

Add the following snippet to your declarative configuration file:

_format_version: "3.0"
vaults:
- config:
    project_id: project_id
  description: Storing secrets in GCP Secret Manager
  name: gcp
  prefix: gcp-sm-vault

With the Vault entity in place, you can reference the GCP secrets through it:

{vault://gcp-sm-vault/secret-name/foo}
{vault://gcp-sm-vault/secret-name/snip}

Vault entity configuration options

Use the following configuration options to configure the vaults entity through any of the supported tools:

• Admin API
• Declarative configuration
• Kong Manager
• Konnect

Configuration options for a GCP Secret Manager vault in Kong Gateway:

Common options: