Google Pub/Sub Nodes

Google Cloud Pub/Sub is a fully managed, real-time messaging service used for event streaming, microservice communication, and data pipeline ingestion. MaestroHub provides a Publish node so you can send messages to Pub/Sub topics within your pipelines.

Configuration Quick Reference

Field	What you choose	Details
Parameters	Connection, Function, Function Parameters, Timeout Override	Select the connection profile, function, configure function parameters with expression support, and optionally override timeout.
Settings	Description, Timeout (seconds), Retry on Timeout, Retry on Fail, On Error	Node description, maximum execution time, retry behavior on timeout or failure, and error handling strategy. All execution settings default to pipeline-level values.

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Google Pub/Sub Publish Node

Google Pub/Sub Publish Node

Publish messages to Google Pub/Sub topics with support for ordering keys, custom attributes, and dynamic payload templates.

Supported Function Types:

Function Name	Purpose	Common Use Cases
Publish	Send messages to a Pub/Sub topic with configurable payload, ordering key, and attributes	Event broadcasting, IoT telemetry streaming, cross-service notifications, data pipeline ingestion

How It Works

When the pipeline executes, the Publish node:

1. Connects to Google Cloud Pub/Sub using the selected connection profile
2. Serializes the message payload (JSON or text) with the configured ordering key and attributes
3. Publishes the message to the target topic via the Pub/Sub gRPC API
4. Returns delivery confirmation including the message ID assigned by Pub/Sub

Configuration

Field	What you choose	Details
Connection	Google Pub/Sub connection profile	Select a pre-configured connection from your connection library
Function	Publish function	Choose a Pub/Sub Publish function that defines the topic, payload, ordering key, and attributes
Function Parameters	Message values	Configure dynamic values for topic, payload, ordering key, and attributes using expressions or constants

For detailed function configuration options including ordering key semantics and attribute formatting, see the Google Pub/Sub Publish Function documentation.

Looking for event-driven pipeline triggers?

If you want to automatically start a pipeline when Pub/Sub messages arrive (rather than publish within an already-running pipeline), use the Google Pub/Sub Trigger Node instead.

Output

The Publish node delivers its data under result, and execution facts (success, functionId, durationMs, timestamp) under _metadata:

Expression	Description
$node["Name"].result.messageId	The id Pub/Sub assigned — correlate it with subscriber-side observations
$node["Name"].result.topic	The topic published to
$node["Name"].result.messageSize	Payload size in bytes
$node["Name"].result.orderingKey	The ordering key used, empty when none
$node["Name"]._metadata.method, $node["Name"]._metadata.connectionId, $node["Name"]._metadata.protocol	The call's own facts: the operation, the connection it ran over, and googlepubsub