teleport/lib/events/firestoreevents

Firestore Events backend implementation for Teleport.

Introduction

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

WARNING: Using Firestore events involves recurring charge from GCP.

Building

Firestore events 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:
    audit_events_uri: 'firestore://events?projectID=gcp-proj-with-firestore-enabled&credentialsPath=/var/lib/teleport/gcs_creds'

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

Full Properties

The full list of configurable properties for this backend are:

• host portion of URI is the Firestore collection used to persist stored events
• credentialsPath (string, path to GCP creds for Firestore, not-required)
• projectID (string, project ID, required)
• purgeInterval (time duration, poll interval to sweep expired documents, not-required, defaults to once per minute)
• retryPeriod (time duration, retry period for all background tasks, not-required, defaults to 10 seconds)
• disableExpiredDocumentPurge (bool, disables expired document purging, not-required, defaults to false)
• eventRetentionPeriod (int, buffer size for watched events, not-required, defaults to 1024)
• endpoint (string, firestore client endpoint, not-required, ex: localhost:8618)

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 the concatenation of the session ID (a UUID) and event type joined with a dash -, ex: 13498a42-69a8-4fa2-b39d-b0c49e346713-user.login.

Expired event purging should be enabled on as few instances as possible to reduce query costs, though there's no harm in having every instance query and purge. Purging is enabled based on the purgeExpiredDocuments property, which defaults to true. Purging is done based on the configurable eventRetentionPeriod property, which defaults to a year. Add this property to the URI to change the retention period.

Two composite indexes are required for this implementation:

1. EventNamespace ascending, then on CreatedAt ascending
2. SessionID ascending, then on EventIndex ascending

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

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