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Google Pub/Sub Trigger

Listens to Google Pub/Sub messages
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Overview

This node listens to messages from a specified Google Cloud Pub/Sub topic and subscription. It is useful for workflows that need to react to real-time events or data published to a Pub/Sub topic, such as processing messages from IoT devices, user activity logs, or system alerts. The node can automatically create the subscription if it doesn't exist and optionally decode message data from JSON format.

Use Case Examples

  1. A workflow that triggers when a new message is published to a Pub/Sub topic containing user activity data, automatically processing and storing it.
  2. A workflow that listens to system alerts published to a Pub/Sub topic and sends notifications based on the alert content.

Properties

Name Meaning
Project Id. Google Cloud project id used to identify the project containing the Pub/Sub topic and subscription.
Topic Name of the Google Pub/Sub topic to listen to for incoming messages.
Subscription Name of the Google Pub/Sub subscription for the topic. The subscription will be created if it does not exist.
Decode JSON If enabled, the node will automatically decode the message data from JSON format into a JavaScript object.

Output

JSON

  • id - The unique identifier of the received Pub/Sub message.
  • data - The content of the message, either as a decoded JSON object or a plain string depending on the Decode JSON setting.
  • attributes - Attributes associated with the Pub/Sub message, if any.

Dependencies

  • Google Cloud Pub/Sub API
  • Google Auth Library

Troubleshooting

  • Ensure that the provided Google Cloud project ID, topic, and subscription names are correct and that the authenticated service account has the necessary Pub/Sub permissions.
  • If the subscription does not exist, the node attempts to create it; ensure the service account has permission to create subscriptions.
  • If Decode JSON is enabled but the message data is not valid JSON, a warning will be logged and the raw string will be used instead.
  • Timeout error may occur if no message is received within 30 seconds during manual trigger execution; this timeout does not apply to active workflows.

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