> ## Documentation Index
> Fetch the complete documentation index at: https://docs.streamnative.io/llms.txt
> Use this file to discover all available pages before exploring further.

> The Google Pub/Sub sink connector is used to write messages from Apache Pulsar topics to Google Cloud Pub/Sub.

# Google pubsub sink

<Note title="✅ Available on StreamNative Cloud">
  This connector is available as a built-in connector on StreamNative Cloud.
</Note>

The [Google Cloud PubSub](https://cloud.google.com/pubsub) sink connector pulls data from Pulsar topics and persists data to Google Cloud PubSub tables.

<img src="https://mintcdn.com/streamnative/b3-WWYgGULHfAMpu/images/connectors/sync/google-pubsub-google-pubsub-sink.png?fit=max&auto=format&n=b3-WWYgGULHfAMpu&q=85&s=6a8bb5b32e0172d003e48afde7521e3a" alt="" width="816" height="360" data-path="images/connectors/sync/google-pubsub-google-pubsub-sink.png" />

## Quick start

### Prerequisites

The prerequisites for connecting an Google PubSub sink connector to external systems include:

1. Create Google PubSub Topic in Google Cloud.
2. Create the [Gcloud ServiceAccount](https://cloud.google.com/iam/docs/service-accounts-create) and create a public key certificate.
3. Create the [Gcloud Role](https://cloud.google.com/iam/docs/creating-custom-roles), ensure the Google Cloud role have the following permissions:

```text theme={null}
- pubsub.topics.create
- pubsub.topics.get
- pubsub.topics.publish
```

4. Grant the service account the above role permissions.

### 1. Create a connector

The following command shows how to use [pulsarctl](https://github.com/streamnative/pulsarctl) to create a `builtin` connector. If you want to create a `non-builtin` connector,
you need to replace `--sink-type google-pubsub` with `--archive /path/to/pulsar-io-google-pubsub.nar`. You can find the button to download the `nar` package at the beginning of the document.

<Note title="For StreamNative Cloud User">
  If you are a StreamNative Cloud user, you need [set up your environment](https://docs.streamnative.io/docs/connector-setup) first.
</Note>

```bash theme={null}
pulsarctl sinks create \
  --sink-type google-pubsub \
  --name pubsub-sink \
  --tenant public \
  --namespace default \
  --inputs "Your topic name" \
  --parallelism 1 \
  --sink-config \
  '{
    "pubsubProjectId": "Your google pubsub project Id", 
    "pubsubTopicId": "Your google pubsub Topic name",
    "pubsubCredential": "The escaped and compressed public key certificate you created above"
  }'
```

The `--sink-config` is the minimum necessary configuration for starting this connector, and it is a JSON string. You need to substitute the relevant parameters with your own.
If you want to configure more parameters, see [Configuration Properties](#configuration-properties) for reference.

<Note title="Note">
  You can also choose to use a variety of other tools to create a connector:

  * [pulsar-admin](https://pulsar.apache.org/docs/3.1.x/io-use/): The command arguments for `pulsar-admin` are similar to those of `pulsarctl`. You can find an example for [StreamNative Cloud Doc](https://docs.streamnative.io/docs/connector-create#create-a-built-in-connector).
  * [RestAPI](https://pulsar.apache.org/sink-rest-api/?version=3.1.1): You can find an example for [StreamNative Cloud Doc](https://docs.streamnative.io/docs/connector-create#create-a-built-in-connector).
  * [Terraform](https://github.com/hashicorp/terraform): You can find an example for [StreamNative Cloud Doc](https://docs.streamnative.io/docs/connector-create#create-a-built-in-connector).
  * [Function Mesh](https://functionmesh.io/docs/connectors/run-connector): The docker image can be found at the beginning of the document.
</Note>

### 2. Send messages to the topic

<Note title="Note">
  If your connector is created on StreamNative Cloud, you need to authenticate your clients. See [Build applications using Pulsar clients](https://docs.streamnative.io/docs/qs-connect#jumpstart-for-beginners) for more information.
</Note>

```java theme={null}
public class TestProduce {
 
    public static void main(String[] args) {
        PulsarClient client = PulsarClient.builder()
        .serviceUrl("{{Your Pulsar URL}}")
        .build();

        Producer<byte[]> producer = client.newProducer()
            .topic("{{Your topic name}}")
            .create();

        for (int i = 0; i < 10; i++) {
            String message = "my-message-" + i;
            MessageId msgID = producer.send(message.getBytes());
            System.out.println("Publish " + "my-message-" + i
                    + " and message ID " + msgID);
        }
        
        producer.close();
        client.close();  
    }
}

```

### 3. Show data on Google PubSub

You can create a subscription and pull data from the Google Pub/Sub console.

```text theme={null}
+---------------------------+-----------------+------------------|
| Publish time              | Attribute keys  |  Message body    |   
+---------------------------+-----------------+------------------|
| Feb 19, 2024, 4:17:42 PM  |               - | my-message-0     |
| Feb 19, 2024, 4:17:42 PM  |               - | my-message-1     |
| Feb 19, 2024, 4:17:42 PM  |               - | my-message-2     |
| Feb 19, 2024, 4:17:42 PM  |               - | my-message-3     |
| Feb 19, 2024, 4:17:43 PM  |               - | my-message-4     |
| Feb 19, 2024, 4:17:43 PM  |               - | my-message-5     |
| Feb 19, 2024, 4:17:43 PM  |               - | my-message-6     |
| Feb 19, 2024, 4:17:43 PM  |               - | my-message-7     |
| Feb 19, 2024, 4:17:44 PM  |               - | my-message-8     |
| Feb 19, 2024, 4:17:44 PM  |               - | my-message-9     |
+---------------------------+-----------------+------------------|
```

## Configuration Properties

Before using the Google Cloud PubSub sink connector, you need to configure it. This table outlines the properties and the descriptions.

| Name                     | Type   | Required | Sensitive | Default            | Description                                                                                                                                                                                                    |
| ------------------------ | ------ | -------- | --------- | ------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `pubsubCredential`       | String | true     | true      | "" (empty string)  | The credential (JSON string) for accessing the Google Cloud. It needs to be compressed and escaping before use.                                                                                                |
| `pubsubProjectId`        | String | true     | false     | "" (empty string)  | The Google Cloud project ID.                                                                                                                                                                                   |
| `pubsubTopicId`          | String | true     | false     | " " (empty string) | The topic ID. It is used to read messages from or write messages to Google Cloud Pub/Sub topics.                                                                                                               |
| `pubsubSchemaId`         | String | false    | false     | "" (empty string)  | The schema ID. You must set the schema ID when creating a schema for Google Cloud Pub/Sub topics.                                                                                                              |
| `pubsubSchemaType`       | String | false    | false     | "" (empty string)  | The schema type. You must set the schema type when creating a schema for Google Cloud Pub/Sub topics. Currently, only the AVRO format is supported.                                                            |
| `pubsubSchemaEncoding`   | String | false    | false     | "" (empty string)  | The encoding of the schema. You must set the schema encoding when creating a schema for Google Cloud Pub/Sub topics. Currently, only the JSON format is supported.                                             |
| `pubsubSchemaDefinition` | String | false    | false     | "" (empty string)  | The definition of the schema. It is used to create a schema to or parse messages from Google Cloud Pub/Sub topics.                                                                                             |
| `subscriptionName`       | String | false    | false     | "" (empty string)  | The fully-qualified subscription name to read from (e.g., projects/my-sub-project/subscriptions/my-sub). If not set, a subscription is created in the pubsubProjectId with the same name as the pubsubTopicId. |