Google Pub/Sub Source Connector for Confluent Cloud

Note

If you are installing the connector locally for Confluent Platform, see Google Cloud Pub/Sub Source Connector for Confluent Platform.

The Kafka Connect Google Pub/Sub Source connector for Confluent Cloud can obtain a snapshot of the existing data in a Google Pub/Sub database and then monitor and record all subsequent row-level changes to that data. All of the events for each table are recorded in a separate Apache Kafka® topic. The events can then be easily consumed by applications and services. Note that deleted records are not captured.

Features

Important

If you are still on Confluent Cloud Enterprise, please contact your Confluent Account Executive for more information about using this connector.

The Google Pub/Sub source connector provides the following features:

• Fetches records from a Pub/Sub topic through a subscription.

• Select configuration properties:

  • gcp.pubsub.max.retry.time=5

  • gcp.pubsub.message.max.count=10000

    Configuration properties that are not shown in the Confluent Cloud UI use the default values. See Google Cloud Pub/Sub Source Connector Configuration Properties for default values and property definitions.

For more information, see the Confluent Cloud connector limitations.

Quick Start

Use this quick start to get up and running with the Confluent Cloud Google Pub/Sub source connector. The quick start provides the basics of selecting the connector and configuring it to obtain a snapshot of the existing data in a Google Pub/Sub database and then monitoring and recording all subsequent row-level changes.

Prerequisites

• Authorized access to a Confluent Cloud cluster on Amazon Web Services (AWS), Microsoft Azure (Azure), or Google Cloud Platform (GCP).
• A Google Cloud Pub/Sub subscription and topic.
• A GCP service account. You download service account credentials as a JSON file. These credentials are used when setting up the connector configuration.
• The Confluent Cloud CLI installed and configured for the cluster. See Install and Configure the Confluent Cloud CLI.
• At least one topic must exist in your Confluent Cloud cluster before creating the connector. If you want a topic prefix, the name of the topic you create must include the prefix.

• Kafka cluster credentials. You can use one of the following ways to get credentials:
  • Create a Confluent Cloud API key and secret. To create a key and secret, go to Kafka API keys in your cluster or you can autogenerate the API key and secret directly in the UI when setting up the connector.
  • Create a Confluent Cloud service account for the connector.

Using the Confluent Cloud GUI

Step 1: Launch your Confluent Cloud cluster.

See the Quick Start for Apache Kafka using Confluent Cloud for installation instructions.

Step 2: Add a connector.

Click Connectors. If you already have connectors in your cluster, click Add connector.

Step 3: Select your connector.

Click the Google Cloud Pub/Sub Source connector icon.

Step 4: Set up the connection.

Complete the following and click Continue.

Note

• Make sure you have all your prerequisites completed.
• An asterisk ( * ) designates a required entry.

1. Enter a connector name.

2. Enter your Kafka Cluster credentials. The credentials are either the API key and secret or the service account API key and secret.

3. Enter the topic name where you want to send data. You use this configuration to specify a Kafka topic or topics.

   Note

   The topic must be created before before creating and launching this connector.

4. Upload your GCP credentials JSON file.

5. Enter your Google Pub/Sub Project, Topic, and Subscription IDs.

6. Enter the connection details:

   • Maximum number of messages polled: 10000
   • Maximum time in seconds to retry on errors: 5
   
   

7. Enter the number of tasks for the connector.

Configuration properties that are not shown in the Confluent Cloud UI use the default values. For default values and property definitions, see Google Cloud Pub/Sub Source Connector Configuration Properties.

Step 5: Launch the connector.

Verify the connection details and click Launch.

Step 6: Check the connector status.

The status for the connector should go from Provisioning to Running. It may take a few minutes.

Step 7: Check the Kafka topic.

After the connector is running, verify that messages are populating your Kafka topic.

For additional information about this connector see Google Cloud Pub/Sub Source Connector Configuration Properties. Note that not all Confluent Platform connector features are provided in the Confluent Cloud connector.

See also

For an example that shows fully-managed Confluent Cloud connectors in action with Confluent Cloud ksqlDB, see the Cloud ETL Demo. This example also shows how to use Confluent Cloud CLI to manage your resources in Confluent Cloud.

Using the Confluent Cloud CLI

Complete the following steps to set up and run the connector using the Confluent Cloud CLI.

Note

Make sure you have all your prerequisites completed.

Step 1: List the available connectors.

Enter the following command to list available connectors:

ccloud connector-catalog list

Step 2: Show the required connector configuration properties.

Enter the following command to show the required connector properties:

ccloud connector-catalog describe <connector-catalog-name>

For example:

ccloud connector-catalog describe PubSubSource

Example output:

Following are the required configs:
connector.class
name
kafka.api.key
kafka.api.secret
kafka.topic
gcp.pubsub.credentials.json
gcp.pubsub.project.id
gcp.pubsub.topic.id
gcp.pubsub.subscription.id
tasks.max

Configuration properties that are not shown in the Confluent Cloud UI use the default values. For default values and property definitions, see Google Cloud Pub/Sub Source Connector Configuration Properties.

Step 3: Create the connector configuration file.

Create a JSON file that contains the connector configuration properties. The following example shows the required connector properties.

{
    "name" : "confluent-pubsub-source",
    "connector.class": "PubSubSource",
    "kafka.api.key": "<my-kafka-api-key>",
    "kafka.api.secret" : "<my-kafka-api-secret>",
    "kafka.topic" : "customers",
    "gcp.pubsub.credentials.json" : "omitted",
    "gcp.pubsub.project.id": "<gcp-project-ID>",
    "gcp.pubsub.topic.id":"<pubsub-topic-ID>",
    "gcp.pubsub.subscription.id": "<pubsub-subscription-ID>",
    "tasks.max" : "1"
}

Note the following property definitions:

• "name": Sets a name for your new connector.
• "connector.class": Identifies the connector plugin name.
• "gcp.pubsub.credentials.json": This contains the contents of the downloaded JSON file. See Formatting credentials for details about how to format and use the contents of the downloaded credentials file.

Configuration properties that are not shown in the Confluent Cloud UI use the default values. For default values and property definitions, see Google Cloud Pub/Sub Source Connector Configuration Properties.

Formatting credentials

The contents of the downloaded credentials file must be converted to string format before it can be used in the connector configuration.

1. Convert the JSON file contents into string format. You can use an online converter tool to do this. For example: JSON to String Online Converter.

2. Add an escape character (\) before all \n entries in the Private Key section so that each section begins with \\n (see the highlighted lines below). The example below has been formatted so that the \\n entries are easier to see. Most of the credentials key has been omitted.

   Tip

   A script is available that converts the credentials to a string and also adds the additional \ escape character where needed. See Stringify GCP Credentials.

     {
         "name" : "confluent-pubsub-source",
         "connector.class" : "PubSubSource",
         "kafka.api.key" : "<my-kafka-api-keyk>",
         "kafka.api.secret" : "<my-kafka-api-secret>",
         "gcp.pubsub.credentials.json" : "{\"type\":\"service_account\",\"project_id\":\"connect-
         1234567\",\"private_key_id\":\"omitted\",
         \"private_key\":\"-----BEGIN PRIVATE KEY-----
         \\nMIIEvAIBADANBgkqhkiG9w0BA
         \\n6MhBA9TIXB4dPiYYNOYwbfy0Lki8zGn7T6wovGS5pzsIh
         \\nOAQ8oRolFp\rdwc2cC5wyZ2+E+bhwn
         \\nPdCTW+oZoodY\\nOGB18cCKn5mJRzpiYsb5eGv2fN\/J
         \\n...rest of key omitted...
         \\n-----END PRIVATE KEY-----\\n\",
         \"client_email\":\"pub-sub@connect-123456789.iam.gserviceaccount.com\",
         \"client_id\":\"123456789\",\"auth_uri\":\"https:\/\/accounts.google.com\/o\/oauth2\/
         auth\",\"token_uri\":\"https:\/\/oauth2.googleapis.com\/
         token\",\"auth_provider_x509_cert_url\":\"https:\/\/
         www.googleapis.com\/oauth2\/v1\/
         certs\",\"client_x509_cert_url\":\"https:\/\/www.googleapis.com\/
         robot\/v1\/metadata\/x509\/pub-sub%40connect-
         123456789.iam.gserviceaccount.com\"}",
         "gcp.pubsub.project.id": "<gcp-project-ID>",
         "gcp.pubsub.topic.id":"<pubsub-topic-ID>",
         "gcp.pubsub.subscription.id": "<pubsub-subscription-ID>",
         "tasks.max" : "1"
     }
   

3. Add all the converted string content to the "keyfile" credentials section of your configuration file as shown in the example above.

Step 4: Load the configuration file and create the connector.

Enter the following command to load the configuration and start the connector:

ccloud connector create --config <file-name>.json

For example:

ccloud connector create --config pubsub-source-config.json

Example output:

Created connector confluent-pubsub-source lcc-ix4dl

Step 5: Check the connector status.

Enter the following command to check the connector status:

ccloud connector list

Example output:

ID          |       Name              | Status  | Type
+-----------+-------------------------+---------+-------+
lcc-ix4dl   | confluent-pubsub-source | RUNNING | source

Step 6: Check the Kafka topic.

After the connector is running, verify that messages are populating your Kafka topic.

For additional information about this connector, see Google Cloud Pub/Sub Source Connector Configuration Properties. Note that not all Confluent Platform connector features are provided in the Confluent Cloud connector.

Next Steps

See also

For an example that shows fully-managed Confluent Cloud connectors in action with Confluent Cloud ksqlDB, see the Cloud ETL Demo. This example also shows how to use Confluent Cloud CLI to manage your resources in Confluent Cloud.