---
title: Google Cloud Pub/Sub Integration Guide
slug: litmusedge-v1/how-to-guides/integration-guides/google-cloud-pubsub
description: Learn how to set up the Google Cloud Pub/Sub connector. 
docTags: 
createdAt: 2022-11-24T18:24:54.000Z
---

Review the following guide for setting up an integration between Litmus Edge and [Google Pub/Sub service](https://cloud.google.com/pubsub/docs/overview). 

Once the integration is set up, you can use it for the following: 

- Publishing data from a topic in your edge device to a *Subscription *topic in the Google Cloud Platform (GCP)
- Subscribing to data published by a *Publication *topic in the Google Cloud Platform

# Before You Begin

- You need to create a Google Service Account. Make sure the account has the correct roles and permissions required for setting up the connection. 
- Refer to the following Google resources for learning more about Pub/Sub and configuring connections:
  - [Google Pub/Sub service](https://cloud.google.com/pubsub/docs/overview)
  - [Configure Private Google Access for on-premises hosts > Domain Options ](https://cloud.google.com/vpc/docs/configure-private-google-access-hybrid#config-choose-domain)(information regarding private access to GCP services)
  - [Supported products and limitations > Pub/Sub ](https://cloud.google.com/vpc-service-controls/docs/supported-products#table_pubsub)(information regarding private access to GCP services)
  - [SDK on Publish Settings](https://pkg.go.dev/cloud.google.com/go/pubsub#PublishSettings)
  - [Publish messages to topics](https://cloud.google.com/pubsub/docs/publisher)

# Set up the Outbound Connection (Publish to Google Pub/Sub)

Follow the steps below to set up the outbound connection. 

## Step 1: Create Publication Topic in Google Cloud Platform

In the Google Cloud Platform, create a *publication *topic. A matching *subscription *topic is created automatically, with the *-sub* suffix appended to the topic name.

## Step 2: Add Device

Follow the steps to [Connect a Device](docId:3eyAfPpweuVmBLCEy17sq). The device will be used to store tags that will be eventually used to create outbound topics in the connector. Make sure to select the **Enable Data Store** checkbox. 

## Step 3: Add Tags

After connecting the device in Litmus Edge, you can [Add Tags](docId:8sE7z3PmRfwL1nmzcwaLX) to the device. Create tags that you want to use to create outbound topics for the connector. 

## Step 4: Add the Google Cloud Pub/Sub Connector

Follow the steps to [Add a Connector](docId\:b7eMDh8AO2-NOqDHwPD7Y) and select the **Google Cloud Pub/Sub Connector** provider. 

For more information about message publication settings, see the [SDK on Publish Settings](https://pkg.go.dev/cloud.google.com/go/pubsub#PublishSettings). 

Configure the following parameters. These fields are available for Litmus Edge version 3.11.0 and later. 

- **Name**: Enter a name for the connector. 
- **Service Account Key (.json)**: Copy the JSON key from your Google Cloud Platform and paste it here. For Litmus Edge version 3.11.0 and later, you have the option to upload a file. 
- **The project ID of the cloud project**: Copy the ID from your Google Cloud Platform and paste it here. 
- **The private key ID of the cloud project**: Copy the key ID from your Google Cloud Platform and paste it here. 
- **The client email of the cloud project**: Enter the email from your Google Cloud Platform. 
- **Integration Topic**: Copy the name of the *Publication *topic (without the "-sub" suffix) from your Google Cloud Platform and paste it here.
- **Custom Attributes**:  For Litmus Edge version 3.11.0 and later, you can add custom attributes in key/value pairs for further data processing. Refer to the following to learn more:
  - [Use Custom Attributes in the Google Cloud Pub/Sub Connector](docId\:gW36RAZMeZIiEtUvWLgLd)
  - Google documentation for [Using attributes](https://cloud.google.com/pubsub/docs/publisher#using-attributes)
- **Parallel Publish Count**: The number of messages being published simultaneously. The default value is **100**.  
- **Parallel byte threshold**: The minimum size of a batch (in bytes) for the batch to be published. The default value is zero, which means that there is no threshold (limit). 
- **Publish count threshold**: The minimum number of messages in a batch for the batch to be published. The default value is zero, which means that there is no threshold (limit). 
- **Publish delay threshold (Milliseconds)**: The maximum time that the client will attempt to publish a batch of messages. The default value is zero, which means that there is no threshold (limit). 
- **Throttling limit**: The maximum number of messages per second to be processed. The default value is zero, which means that there is no limit. 
- **Persistent storage**: When enabled, this will cause messages to undergo a store-and-forward procedure. Messages will be stored within Litmus Edge when cloud providers are online.  
- **Queue Mode**: Select the queue mode as **lifo **(last in first out) or **fifo **(first in first out). Selecting **lifo **means that the last data entry is processed first, and selecting **fifo **means the first data entry is processed first. 

## Step 5: Enable the Connector

After adding the connector, click the toggle in the connector tile to enable it. 

::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/z8pQ_cSdvBAp-YYmvkyFf_google.png" size="60" width="388" height="358" position="center" showCaption="false"}

If you see a *Failed *status, you can review the [Connector Logs](docId:5hctoRLhgaX3Ikh_lvi0A) and relevant error messages. 

## Step 6: Create Outbound Topics for Connector

You will now need to import the tags you added in Step 2 to the connector as topics. 

**To create outbound topics:**

1. Click the connector tile.
   The connector *Dashboard *appears. 
2. Click the **Topics **tab. 
3. Click the **Import from DeviceHub** tags icon. 
   The *DeviceHub Import *dialog box appears.

![](https://api.archbee.com/api/optimize/xSuIWwMa6RnsbeD5Kdqd7-zaOGMDYbPZWYALvLBgotp-20250606-203859.png)

After importing the tag(s), do the following:

- Edit the tag and configure the **Remote Data Topic**. Copy and paste the name of the *Subscription *topic  (with the `-sub` suffix) from your Google Cloud Platform.  
- Make sure the connector has a CONNECTED status. 

## Step 7: Enable Topics

Because you imported DeviceHub tags for a *CONNECTED* connector, all topics will be disabled. 

To enable the topics, return to the *Topics *tab and click the **Enable all topics** icon. 

![](https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/Iq7BWYqGWueu4US73iBl3_image.png "Enable all topics icon")

## Step 8: Verify Connection in Google Cloud Platform

**To verify the connection in Google Cloud Platform:**

1. Pull the *subscription *topic to see messages it receives from the Litmus Edge outbound topics created previously. 
   ![](https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/-VdXPYXn3ue8QmzOVGPMD_pubsubmsg1000x272.png "List of Litmus Edge outbound topics")
2. View the *subscription *statistics. 
   ![](https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/u-2c_cHty2BoX6BGFJBKN_pubsubgraph1000x235.png "Graph of subscription statistic")

# Set up the Inbound Connection (Subscribe to Google Pub/Sub)

Follow the steps below to set up the inbound connection. 

See [Publish messages to topics](https://cloud.google.com/pubsub/docs/publisher) to learn more about publishing messages in Google Pub/Sub. 

## Step 1: Create Publication Topic in Google Cloud Platform

In the Google Cloud Platform, create a *publication *topic.

## Step 2: Add the Google Cloud Pub/Sub Connector

Follow the steps to [Add a Connector](docId\:b7eMDh8AO2-NOqDHwPD7Y) and select the **Google Cloud Pub/Sub Connector** provider. 

Configure the following parameters. These fields are available for Litmus Edge version 3.11.0 and later. 

- **Name**: Enter a name for the connector. 
- **Service Account Key (.json)**: Copy the JSON key from your Google Cloud Platform and paste it here. For Litmus Edge version 3.11.0 and later, you have the option to upload a file. 
- **The project ID of the cloud project**: Copy the ID from your Google Cloud Platform and paste it here. 
- **The private key ID of the cloud project**: Copy the key ID from your Google Cloud Platform and paste it here. 
- **The client email of the cloud project**: Enter the email from your Google Cloud Platform. 
- **Integration Topic**: Copy the name of the *Publication *topic (without the "-sub" suffix) from your Google Cloud Platform and paste it here.
- **Custom Attributes**:  For Litmus Edge version 3.11.0 and later, you can add custom attributes in key/value pairs for further data processing. Refer to the following to learn more:
  - [Use Custom Attributes in the Google Cloud Pub/Sub Connector](docId\:gW36RAZMeZIiEtUvWLgLd)
  - Google documentation for [Using attributes](https://cloud.google.com/pubsub/docs/publisher#using-attributes)
- **Parallel Publish Count**: The number of messages being published simultaneously. The default value is **100**.  
- **Parallel byte threshold**: The minimum size of a batch (in bytes) for the batch to be published. The default value is zero, which means that there is no threshold (limit). 
- **Publish count threshold**: The minimum number of messages in a batch for the batch to be published. The default value is zero, which means that there is no threshold (limit). 
- **Publish delay threshold (Milliseconds)**: The maximum time that the client will attempt to publish a batch of messages. The default value is zero, which means that there is no threshold (limit). 
- **Throttling limit**: The maximum number of messages per second to be processed. The default value is zero, which means that there is no limit. 
- **Persistent storage**: When enabled, this will cause messages to undergo a store-and-forward procedure. Messages will be stored within Litmus Edge when cloud providers are online.  
- **Queue Mode**: Select the queue mode as **lifo **(last in first out) or **fifo **(first in first out). Selecting **lifo **means that the last data entry is processed first, and selecting **fifo **means the first data entry is processed first. 

## Step 3: Enable the Connector

After adding the connector, click the toggle in the connector tile to enable it. 

::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/eiB32iROGzvFcrs6xBjad_google.png" size="60" width="388" height="358" position="center" showCaption="false"}

If you see a *Failed *status, you can review the [Connector Logs](docId:5hctoRLhgaX3Ikh_lvi0A) and relevant error messages. 

## Step 4: Create Inbound Topic for Connector

You will now need to create a topic in Litmus Edge from the Google Cloud Platform publication topic created in Step 1. 

**To create inbound topics: **

1. Navigate to **Integration**. 
2. Click the connector tile. 
3. Click the **Topics **tab. 
4. Click the **Add a new subscription** icon.
   The *Data Integration* dialog box appears.
   ![](https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/RhLASRY6moVGfDkGhz12N_googleaddsubscriptionle.png)
5. Configure the following parameters. 
   - **Data Direction**: Select **Remote to Local - Inbound**. 
   - **Local Data Topic**: Enter a name for the topic name in Litmus Edge. 
   - **Remote Data Topic**: Copy and paste the *Publication *topic from your Google Cloud Platform. 
   - **Enable**: Select the toggle to enable the topic. 
6. Click **Yes **to add the topic. 
7. From the connector tile, ensure the connector is not disabled and still shows a CONNECTED status. Also verify the topic shows an *Enabled *status. 

![](https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/dbobD_VeGJHP75dKmzgM0_image.png)

## Step 5: Send Messages in Google Cloud Platform

Start sending messages through the *publication *topic (created in Step 1) from the Google Cloud Platform. See [Publish messages to topics](https://cloud.google.com/pubsub/docs/publisher) to learn more. 

## Step 6: Verify Connection in Litmus Edge

You can do one of the following to verify the connection in Litmus Edge. When configuring the Flow or application, use the the** Local Data Topic** name configured in Step 4. 

- [Create a Flow](docId:7x0n7C4DxswTD61vpIBza) to view the messages coming from Google Pub/Sub through the connector you created. 
- Visualize the incoming data using one of the dedicated [Applications](docId\:j4jhjBWbwQY1BS9A3G6Zk) such as [Grafana](docId\:SUoMePWWNb2wt-m7HD8Hh).