Google Pub/Sub Message Binding v0.2.0

The Google Cloud Pub/Sub message binding defines properties of a message that are specific to the Google Cloud Pub/Sub protocol.

Overview

This binding object allows you to specify message-level configurations, such as an orderingKey to ensure ordered delivery, a map of attributes, and an optional schema definition that the message payload should adhere to.

Message Properties

Property	Type	Required	Description
bindingVersion	string	No	Binding version (defaults to 0.2.0).
attributes	object	No	A map of key-value pairs that can be used for filtering or passing metadata.
orderingKey	string	No	A key that ensures messages with the same key are delivered in order.
schema	object	No	A schema that the message payload should validate against.

schema Object

Property	Type	Required	Description
name	string	Yes	The full resource name of the schema in the format projects/{project}/schemas/{schema}.

Property Details

attributes

A flexible key-value map for sending message metadata. Subscribers can use filters based on these attributes to receive only a subset of messages.

orderingKey

If a message has an ordering key, Pub/Sub will deliver all messages with the same key to subscribers in the order that they were published.

schema

This associates the message with a specific Pub/Sub schema definition (Avro or Protocol Buffers). If the topic that this message is published to has schema validation enabled, the message payload will be validated against this schema.

Example

Message with an Ordering Key and Schema

This example defines a message that represents a user's location update. It specifies that all updates for the same userId must be delivered in order. It also links to a Pub/Sub schema definition that the payload must follow.

messages:
  userLocationUpdate:
    bindings:
      googlepubsub:
        bindingVersion: '0.2.0'
        orderingKey: 'userId'
        attributes:
          sourceSystem: 'mobile-app'
        schema:
          name: 'projects/my-gcp-project/schemas/UserLocation'

Changelog

Version 0.2.0

• The schema object now only contains the name of the schema.
• This version focuses on message-level properties, while topic-level schema settings were moved to the channel binding.