Remove DeadLetterPolicy on subscription

Removes the `DeadLetterPolicy` on a subscription.

Documentation pages that include this code sample

To view the code sample used in context, see the following documentation:

Code Sample

C#

Before trying this sample, follow the C# setup instructions in the Pub/Sub Quickstart Using Client Libraries. For more information, see the Pub/Sub C# API reference documentation.


using Google.Cloud.PubSub.V1;
using Google.Protobuf.WellKnownTypes;

public class RemoveDeadLetterPolicySample
{
    public Subscription RemoveDeadLetterPolicy(string projectId, string topicId, string subscriptionId)
    {
        SubscriberServiceApiClient subscriber = SubscriberServiceApiClient.Create();
        // This is an existing topic that the subscription with dead letter policy is attached to.
        TopicName topicName = TopicName.FromProjectTopic(projectId, topicId);
        // This is an existing subscription with dead letter policy.
        SubscriptionName subscriptionName = SubscriptionName.FromProjectSubscription(projectId, subscriptionId);

        var subscription = new Subscription()
        {
            SubscriptionName = subscriptionName,
            TopicAsTopicName = topicName,
            DeadLetterPolicy = null
        };

        var request = new UpdateSubscriptionRequest
        {
            Subscription = subscription,
            UpdateMask = new FieldMask { Paths = { "dead_letter_policy" } }
        };
        var updatedSubscription = subscriber.UpdateSubscription(request);
        return updatedSubscription;
    }
}

C++

Before trying this sample, follow the C++ setup instructions in the Pub/Sub Quickstart Using Client Libraries. For more information, see the Pub/Sub C++ API reference documentation.

namespace pubsub = google::cloud::pubsub;
[](pubsub::SubscriptionAdminClient client, std::string const& project_id,
   std::string const& subscription_id) {
  auto sub = client.UpdateSubscription(
      pubsub::Subscription(project_id, std::move(subscription_id)),
      pubsub::SubscriptionBuilder{}.clear_dead_letter_policy());
  if (!sub) return;  // TODO(#4792) - emulator lacks UpdateSubscription()

  std::cout << "The subscription has been updated to: " << sub->DebugString()
            << "\n";
}

Go

Before trying this sample, follow the Go setup instructions in the Pub/Sub Quickstart Using Client Libraries. For more information, see the Pub/Sub Go API reference documentation.

import (
	"context"
	"fmt"
	"io"

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

// removeDeadLetterTopic removes the dead letter policy from a subscription.
func removeDeadLetterTopic(w io.Writer, projectID, subID string) error {
	// projectID := "my-project-id"
	// subID := "my-sub"
	ctx := context.Background()
	client, err := pubsub.NewClient(ctx, projectID)
	if err != nil {
		return fmt.Errorf("pubsub.NewClient: %v", err)
	}

	subConfig, err := client.Subscription(subID).Update(ctx, pubsub.SubscriptionConfigToUpdate{
		DeadLetterPolicy: &pubsub.DeadLetterPolicy{},
	})
	if err != nil {
		return fmt.Errorf("Update: %v", err)
	}
	fmt.Fprintf(w, "Updated subscription config: %+v\n", subConfig)
	return nil
}

Java

Before trying this sample, follow the Java setup instructions in the Pub/Sub Quickstart Using Client Libraries. For more information, see the Pub/Sub Java API reference documentation.


import com.google.cloud.pubsub.v1.SubscriptionAdminClient;
import com.google.protobuf.FieldMask;
import com.google.pubsub.v1.ProjectSubscriptionName;
import com.google.pubsub.v1.Subscription;
import com.google.pubsub.v1.TopicName;
import com.google.pubsub.v1.UpdateSubscriptionRequest;

public class RemoveDeadLetterPolicyExample {

  public static void main(String... args) throws Exception {
    // TODO(developer): Replace these variables before running the sample.
    String projectId = "your-project-id";
    // This is an existing subscription with dead letter policy.
    String subscriptionId = "your-subscription-id";
    // This is an existing topic that the subscription with dead letter policy is attached to.
    String topicId = "your-topic-id";

    RemoveDeadLetterPolicyExample.removeDeadLetterPolicyExample(projectId, subscriptionId, topicId);
  }

  public static void removeDeadLetterPolicyExample(
      String projectId, String subscriptionId, String topicId) throws Exception {
    try (SubscriptionAdminClient subscriptionAdminClient = SubscriptionAdminClient.create()) {

      ProjectSubscriptionName subscriptionName =
          ProjectSubscriptionName.of(projectId, subscriptionId);
      TopicName topicName = TopicName.of(projectId, topicId);

      // Construct the subscription you expect to have after the request. Here,
      // values in the required fields (name, topic) help identify the subscription.
      // No dead letter policy is supplied.
      Subscription expectedSubscription =
          Subscription.newBuilder()
              .setName(subscriptionName.toString())
              .setTopic(topicName.toString())
              .build();

      // Construct a field mask to indicate which field to update in the subscription.
      FieldMask updateMask =
          FieldMask.newBuilder()
              .addPaths("dead_letter_policy")
              .build();

      UpdateSubscriptionRequest request =
          UpdateSubscriptionRequest.newBuilder()
              .setSubscription(expectedSubscription)
              .setUpdateMask(updateMask)
              .build();

      Subscription response = subscriptionAdminClient.updateSubscription(request);

      // You should see an empty dead letter topic field inside the dead letter policy.
      System.out.println("After: " + response.getAllFields());
    }
  }
}

Node.js

Before trying this sample, follow the Node.js setup instructions in the Pub/Sub Quickstart Using Client Libraries. For more information, see the Pub/Sub Node.js API reference documentation.

/**
 * TODO(developer): Uncomment these variables before running the sample.
 */
// const topicName = 'YOUR_TOPIC_NAME';
// const subscriptionName = 'YOUR_SUBSCRIPTION_NAME';

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

// Creates a client; cache this for further use
const pubSubClient = new PubSub();

async function removeDeadLetterPolicy() {
  const metadata = {
    deadLetterPolicy: null,
  };

  await pubSubClient
    .topic(topicName)
    .subscription(subscriptionName)
    .setMetadata(metadata);

  console.log(
    `Removed dead letter topic from ${subscriptionName} subscription.`
  );
}

removeDeadLetterPolicy().catch(console.error);

PHP

Before trying this sample, follow the PHP setup instructions in the Pub/Sub Quickstart Using Client Libraries. For more information, see the Pub/Sub PHP API reference documentation.

use Google\Cloud\PubSub\PubSubClient;

/**
 * Remove dead letter policy from an existing subscription.
 *
 * @param string $projectId  The Google project ID.
 * @param string $topicName  The Pub/Sub topic name.
 * @param string $subscriptionName  The Pub/Sub subscription name.
 */
function dead_letter_remove($projectId, $topicName, $subscriptionName)
{
    $pubsub = new PubSubClient([
        'projectId' => $projectId,
    ]);

    $topic = $pubsub->topic($topicName);

    $subscription = $topic->subscription($subscriptionName);

    // Provide deadLetterPolicy in the update mask, but omit from update fields to unset.
    $subscription->update([], [
        'updateMask' => [
            'deadLetterPolicy'
        ]
    ]);

    printf(
        'Removed dead letter topic from subscription %s' . PHP_EOL,
        $subscription->name()
    );
}

Python

Before trying this sample, follow the Python setup instructions in the Pub/Sub Quickstart Using Client Libraries. For more information, see the Pub/Sub Python API reference documentation.

from google.cloud import pubsub_v1
from google.cloud.pubsub_v1.types import FieldMask

# TODO(developer)
# project_id = "your-project-id"
# TODO(developer): This is an existing topic that the subscription
# with dead letter policy is attached to.
# topic_id = "your-topic-id"
# TODO(developer): This is an existing subscription with a dead letter policy.
# subscription_id = "your-subscription-id"

publisher = pubsub_v1.PublisherClient()
subscriber = pubsub_v1.SubscriberClient()
topic_path = publisher.topic_path(project_id, topic_id)
subscription_path = subscriber.subscription_path(project_id, subscription_id)

subscription_before_update = subscriber.get_subscription(
    request={"subscription": subscription_path}
)
print(f"Before removing the policy: {subscription_before_update}.")

# Indicates which fields in the provided subscription to update.
update_mask = FieldMask(paths=["dead_letter_policy"])

# Construct the subscription (without any dead letter policy) that you
# expect to have after the update.
subscription = pubsub_v1.types.Subscription(
    name=subscription_path, topic=topic_path
)

with subscriber:
    subscription_after_update = subscriber.update_subscription(
        request={"subscription": subscription, "update_mask": update_mask}
    )

print(f"After removing the policy: {subscription_after_update}.")

Ruby

Before trying this sample, follow the Ruby setup instructions in the Pub/Sub Quickstart Using Client Libraries. For more information, see the Pub/Sub Ruby API reference documentation.

# subscription_name = "Your Pubsub subscription name"
require "google/cloud/pubsub"

pubsub = Google::Cloud::Pubsub.new

subscription = pubsub.subscription subscription_name
subscription.remove_dead_letter_policy
puts "Removed dead letter topic from #{subscription_name} subscription."