teleport/lib/backend/firestore

Firestore backend implementation for Teleport.

Introduction

This package enables Teleport auth server to store secrets in Firestore on GCP.

WARNING: Using Firestore involves recurring charge from GCP.

Building

Firestore backend is not enabled by default. To enable it you have to compile Teleport with firestore build flag.

To build Teleport with Firestore enabled, run:

ADDFLAGS='-tags firestore' make teleport

Quick Start

There are currently two Firestore mode options for any given GCP Project; Native mode and Datastore Mode. This storage backend uses Real-time updates to keep individual auth instances in sync and requires Firestore configured in Native mode.

Add this storage configuration in teleport section of the config file (by default it's /etc/teleport.yaml):

teleport:
  storage:
    type: firestore
    collection_name: cluster-data
    credentials_path: /var/lib/teleport/firestore_creds
    project_id: gcp-proj-with-firestore-enabled

Collections are automatically created by the Firestore APIs and the required indexes are created by the backend on first start, if they do not exist.

Encryption

Lifted from Google docs; Cloud Firestore automatically encrypts all data before it is written to disk. There is no setup or configuration required and no need to modify the way you access the service. The data is automatically and transparently decrypted when read by an authorized user.

With server-side encryption, Google manages the cryptographic keys on your behalf using the same hardened key management systems that we use for our own encrypted data, including strict key access controls and auditing. Each Cloud Firestore object's data and metadata is encrypted under the 256-bit Advanced Encryption Standard, and each encryption key is itself encrypted with a regularly rotated set of master keys.

Full Properties

The full list of configurable properties for this backend are:

• credentials_path (string, path to GCP creds for Firestore, not-required)
• project_id (string, project ID, required)
• collection_name (string, collection for cluster information, required)
• purge_expired_documents_poll_interval (time duration, poll interval to sweep expired documents, not-required, defaults to once per minute)
• retry_period (time duration, retry period for all background tasks, not-required, defaults to 10 seconds)
• disable_expired_document_purge (bool, disables expired document purging, not-required, defaults to false)
• buffer_size (int, buffer size for watched events, not-required, defaults to 1024)
• endpoint (string, firestore client endpoint, not-required, ex: localhost:8618)
• limit_watch_query (bool, forces the watcher to start querying only for records from current time forward, not-required, defaults to false)

Firestore Client Authentication Options

There are three authentication/authorization modes available;

1. With no credentialsPath and no endpoint defined, the Firestore clients will use Google Application Default Credentials for authentication. This only works in cases where Teleport is installed on GCE instances and have service accounts with IAM role/profile associations authorizing that GCE instance to use Firestore.
2. With endpoint defined, Firestore will create clients no auth, GRPC in-secure, clients pointed at the specified endpoint. This is only used for tests, see Tests section below.
3. With credentialsPath defined, Firestore will create clients authenticating against live systems with the Service Account bound to the JSON key file referenced in the option.

Implementation Details

Firestore Document IDs must be unique, cannot start with periods, and cannot contain forward slashes. In order to support more straight forward fetching but work within the requirements of Firestore, Document IDs are SHA1 hashed from the records key.

Realtime updates are consumed across the cluster via Firestore's ability to watch for document updates.

One composite indexes is required for this implementation:

1. key ascending, then on expires ascending

Composite indexes should be limited to the specific collection set in the configuration (in the aforementioned example is cluster-data).

Tests

Tests must execute one of two ways:

1. With gcloud installed in test infrastructure and the firestore emulator enabled and running to a dynamic port a pre-defined port used in the config. Ex: gcloud beta emulators firestore start --host-port=localhost:8618. This is where the Firestore config parameter endpoint is used.
2. With a service account pointed a test GCP project and or test collections.

Get Help

This backend has been contributed by https://github.com/joshdurbin