Google Cloud Pub/Sub Source Connector

The Google Cloud Pub/Sub source connector feeds data from Google Cloud Pub/Sub topics and writes data to Pulsar topics.

Quick start

Prerequisites

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

Create Google PubSub Topic in Google Cloud.
Create the Gcloud ServiceAccount and create a public key certificate.
Create the Gcloud Role, ensure the Google Cloud role have the following permissions:

- pubsub.subscriptions.consume
- pubsub.subscriptions.create
- pubsub.subscriptions.get
- pubsub.subscriptions.update
- pubsub.topics.attachSubscription

Grant the service account the above role permissions.

1. Create a connector

The following command shows how to use pulsarctl to create a builtin connector. If you want to create a non-builtin connector, you need to replace --source-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.

For StreamNative Cloud User

If you are a StreamNative Cloud user, you need set up your environment first.

pulsarctl sources create \
  --source-type google-pubsub \
  --name pubsub-source \
  --tenant public \
  --namespace default \
  --destination-topic-name "Your topic name" \
  --parallelism 1 \
  --source-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 --source-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 for reference.

Note

You can also choose to use a variety of other tools to create a connector:

pulsar-admin: The command arguments for pulsar-admin are similar to those of pulsarctl. You can find an example for StreamNative Cloud Doc.
RestAPI: You can find an example for StreamNative Cloud Doc.
Terraform: You can find an example for StreamNative Cloud Doc.
Function Mesh: The docker image can be found at the beginning of the document.

2. Write data to Google PubSub topic

Send some messages to the Google Cloud PubSub using the gcloud CLI tool

gcloud pubsub topics publish {{Your PubSub Topic Name}} --message="my-message-0"
gcloud pubsub topics publish {{Your PubSub Topic Name}} --message="my-message-1"
gcloud pubsub topics publish {{Your PubSub Topic Name}} --message="my-message-2"
gcloud pubsub topics publish {{Your PubSub Topic Name}} --message="my-message-3"
gcloud pubsub topics publish {{Your PubSub Topic Name}} --message="my-message-4"
gcloud pubsub topics publish {{Your PubSub Topic Name}} --message="my-message-5"
gcloud pubsub topics publish {{Your PubSub Topic Name}} --message="my-message-6"
gcloud pubsub topics publish {{Your PubSub Topic Name}} --message="my-message-7"
gcloud pubsub topics publish {{Your PubSub Topic Name}} --message="my-message-8"
gcloud pubsub topics publish {{Your PubSub Topic Name}} --message="my-message-9"

3. Show data by Pulsar Consumer

Note

If your connector is created on StreamNative Cloud, you need to authenticate your clients. See Build applications using Pulsar clients for more information.

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

        Consumer<GenericRecord> consumer = client.newConsumer(Schema.AUTO_CONSUME())
                                                 .topic("{{The topic name that you specified when you created the connector}}")
                                                 .subscriptionName(subscription)
                                                 .subscriptionInitialPosition(SubscriptionInitialPosition.Earliest)
                                                 .subscribe();
        Consumer<byte[]> consumer = client.newConsumer()
                .topic("{{The topic name that you specified when you created the connector}}")
                .subscriptionName("test-sub")
                .subscriptionInitialPosition(SubscriptionInitialPosition.Earliest)
                .subscribe();

        for (int i = 0; i < 10; i++) {
          Message<byte[]> msg = consumer.receive();
          consumer.acknowledge(msg);
          System.out.println("Receive message " + new String(msg.getData()));
        }
        client.close();  
    }
    // output
    // Receive message my-message-0
    // Receive message my-message-1
    // Receive message my-message-2
    // Receive message my-message-3
    // Receive message my-message-4
    // Receive message my-message-5
    // Receive message my-message-6
    // Receive message my-message-7
    // Receive message my-message-8
    // Receive message my-message-9

Configuration Properties

Before using the Google PubSub source 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.