Create a new Pub/Sub notification

Add a Pub/Sub notification to a Cloud Storage bucket.

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For detailed documentation that includes this code sample, see the following:

Code sample

C++

For more information, see the Cloud Storage C++ API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

namespace gcs = ::google::cloud::storage;
using ::google::cloud::StatusOr;
[](gcs::Client client, std::string const& bucket_name,
   std::string const& topic_name) {
  StatusOr<gcs::NotificationMetadata> notification =
      client.CreateNotification(bucket_name, topic_name,
                                gcs::NotificationMetadata());
  if (!notification) throw std::move(notification).status();

  std::cout << "Successfully created notification " << notification->id()
            << " for bucket " << bucket_name << "\n";
  std::cout << "Full details for the notification:\n"
            << *notification << "\n";
}

C#

For more information, see the Cloud Storage C# API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.


using Google.Apis.Storage.v1.Data;
using Google.Cloud.Storage.V1;
using System;

public class CreatePubSubNotificationSample
{
    public Notification CreatePubSubNotification(
        string bucketName = "your-unique-bucket-name",
        string topic = "my-topic")
    {
        StorageClient storage = StorageClient.Create();
        Notification notification = new Notification
        {
            Topic = topic,
            PayloadFormat = "JSON_API_V1"
        };

        Notification createdNotification = storage.CreateNotification(bucketName, notification);
        Console.WriteLine("Notification subscription created with ID: " + createdNotification.Id + " for bucket name " + bucketName);
        return createdNotification;
    }
}

Go

For more information, see the Cloud Storage Go API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

import (
	"context"
	"fmt"
	"io"

	"cloud.google.com/go/storage"
)

// createBucketNotification creates a notification configuration for a bucket.
func createBucketNotification(w io.Writer, projectID, bucketName, topic string) error {
	// projectID := "my-project-id"
	// bucketName := "bucket-name"
	// topic := "topic-name"

	ctx := context.Background()
	client, err := storage.NewClient(ctx)
	if err != nil {
		return fmt.Errorf("storage.NewClient: %w", err)
	}
	defer client.Close()

	notification := storage.Notification{
		TopicID:        topic,
		TopicProjectID: projectID,
		PayloadFormat:  storage.JSONPayload,
	}

	createdNotification, err := client.Bucket(bucketName).AddNotification(ctx, &notification)
	if err != nil {
		return fmt.Errorf("Bucket.AddNotification: %w", err)
	}
	fmt.Fprintf(w, "Successfully created notification with ID %s for bucket %s.\n", createdNotification.ID, bucketName)
	return nil
}

Java

For more information, see the Cloud Storage Java API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

import com.google.cloud.storage.Notification;
import com.google.cloud.storage.NotificationInfo;
import com.google.cloud.storage.NotificationInfo.EventType;
import com.google.cloud.storage.NotificationInfo.PayloadFormat;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;
import java.util.Map;

public class CreateBucketPubSubNotification {

  public static void createBucketPubSubNotification(
      String bucketName,
      String topicName,
      Map<String, String> customAttributes,
      EventType[] eventTypes,
      String objectNamePrefix,
      PayloadFormat payloadFormat) {
    // The ID to give your GCS bucket
    // String bucketName = "your-unique-bucket-name";

    // The name of the topic you would like to create a notification for
    // String topicName = "projects/{your-project}/topics/{your-topic}";

    // Any custom attributes
    // Map<String, String> customAttributes = Map.of("label", "value");

    // The object name prefix for which this notification configuration applies
    // String objectNamePrefix = "blob-";

    // Desired content of the Payload
    // PayloadFormat payloadFormat = PayloadFormat.JSON_API_V1.JSON_API_V1;

    Storage storage = StorageOptions.newBuilder().build().getService();
    NotificationInfo notificationInfo =
        NotificationInfo.newBuilder(topicName)
            .setCustomAttributes(customAttributes)
            .setEventTypes(eventTypes)
            .setObjectNamePrefix(objectNamePrefix)
            .setPayloadFormat(payloadFormat)
            .build();
    Notification notification = storage.createNotification(bucketName, notificationInfo);
    String topic = notification.getTopic();
    System.out.println("Successfully created notification for topic " + topic);
  }
}

Node.js

For more information, see the Cloud Storage Node.js API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

/**
 * TODO(developer): Uncomment the following lines before running the sample.
 */
// The ID of your GCS bucket
// const bucketName = 'your-unique-bucket-name';

// The name of a topic
// const topic = 'my-topic';

// Imports the Google Cloud client library
const {Storage} = require('@google-cloud/storage');

// Creates a client
const storage = new Storage();

async function createNotification() {
  // Creates a notification
  await storage.bucket(bucketName).createNotification(topic);

  console.log('Notification subscription created.');
}

createNotification().catch(console.error);

PHP

For more information, see the Cloud Storage PHP API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

use Google\Cloud\Storage\StorageClient;

/**
 * Creates a notification configuration for a bucket.
 * This sample is used on this page:
 *   https://cloud.google.com/storage/docs/reporting-changes
 *
 * @param string $bucketName The name of your Cloud Storage bucket.
 *        (e.g. 'my-bucket')
 * @param string $topicName The name of the topic you would like to create a notification.
 *        (e.g. 'my-topic')
 */
function create_bucket_notifications(
    string $bucketName,
    string $topicName
): void {
    $storage = new StorageClient();
    $bucket = $storage->bucket($bucketName);
    $notification = $bucket->createNotification($topicName);

    printf(
        'Successfully created notification with ID %s for bucket %s in topic %s' . PHP_EOL,
        $notification->id(),
        $bucketName,
        $topicName
    );
}

Python

For more information, see the Cloud Storage Python API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

from google.cloud import storage


def create_bucket_notifications(bucket_name, topic_name):
    """Creates a notification configuration for a bucket."""
    # The ID of your GCS bucket
    # bucket_name = "your-bucket-name"
    # The name of a topic
    # topic_name = "your-topic-name"

    storage_client = storage.Client()
    bucket = storage_client.bucket(bucket_name)
    notification = bucket.notification(topic_name=topic_name)
    notification.create()

    print(f"Successfully created notification with ID {notification.notification_id} for bucket {bucket_name}")

Ruby

For more information, see the Cloud Storage Ruby API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

require "google/cloud/storage"

def create_bucket_notifications bucket_name:, topic_name:
  # The ID of your GCS bucket
  # bucket_name = "your-unique-bucket-name"

  # The ID of the pubsub topic
  # topic_name = "your-unique-topic-name"

  storage = Google::Cloud::Storage.new
  bucket  = storage.bucket bucket_name
  notification = bucket.create_notification topic_name

  puts "Successfully created notification with ID #{notification.id} for bucket #{bucket_name}"
end

What's next

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