Version: v1

PubSub Drivers

Google PubSub Driver#

This is the default driver. It uses Google Cloud PubSub to send messages.

It requires the env vars GOOGLE_APPLICATION_CREDENTIALS and GOOGLE_CLOUD_PUB_SUB_PROJECT_ID to function correctly.

NOTE: Make sure the service account is assigned the correct roles

The role assigned to the service account in the credentials should be roles/pubsub.admin

This is required because we require the below permissions:

Permission	Reason
pubsub.topics.publish	Publish to Topic
pubsub.subscriptions.consume	Consume from Subscription
pubsub.topics.get	Get Topic to create subscription for it
pubsub.topics.attachSubscription	Create subscription for a topic
pubsub.subscriptions.get	Get subscription to start consuming it
pubsub.topics.create	Creating Topics Automatically (for publishing, subscribing and DLQs)
pubsub.subscriptions.create	Creating Subscriptions (for subscribing and DLQs)
resourcemanager.projects.get	Get Project Number from Project to bind DLQ policies
pubsub.subscriptions.setIamPolicy	Assigning Subscriber Role for DLQs
pubsub.topics.setIamPolicy	Assigning Publisher Role for DLQs

If you would like to bypass Google PubSub and run your subscriptions synchronously (for development purposes) set the following environment variable:

PUBSUB_DRIVER=synchronous

This uses an EventEmitter based pubsub model, and hence only works inside a single process.

NOTE: Not recommended for production use

This is useful for writing unit tests, read more in the testing guide