Create a notification channel

Demonstrates how to create new notification channels, in the context of recreating policies from a backup.

Explore further

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

• Create and manage notification channels by API

Code sample

C#

To authenticate to Monitoring, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

static void RestorePolicies(string projectId, string filePath)
{
    var policyClient = AlertPolicyServiceClient.Create();
    var channelClient = NotificationChannelServiceClient.Create();
    List<Exception> exceptions = new List<Exception>();
    var backup = JsonConvert.DeserializeObject<BackupRecord>(
        File.ReadAllText(filePath), new ProtoMessageConverter());
    var projectName = new ProjectName(projectId);
    bool isSameProject = projectId == backup.ProjectId;
    // When a channel is recreated, rather than updated, it will get
    // a new name.  We have to update the AlertPolicy with the new
    // name.  Track the names in this map.
    var channelNameMap = new Dictionary<string, string>();
    foreach (NotificationChannel channel in backup.Channels)
    {
        try
        {
            bool updated = false;
            Console.WriteLine("Updating channel.\n{0}",
                channel.DisplayName);
            // This field is immutable and it is illegal to specify a
            // non-default value (UNVERIFIED or VERIFIED) in the
            // Create() or Update() operations.
            channel.VerificationStatus = NotificationChannel.Types
                .VerificationStatus.Unspecified;
            if (isSameProject)
                try
                {
                    channelClient.UpdateNotificationChannel(
                        null, channel);
                    updated = true;
                }
                catch (Grpc.Core.RpcException e)
                when (e.Status.StatusCode == StatusCode.NotFound)
                { }
            if (!updated)
            {
                // The channel no longer exists.  Recreate it.
                string oldName = channel.Name;
                channel.Name = null;
                var response = channelClient.CreateNotificationChannel(
                    projectName, channel);
                channelNameMap.Add(oldName, response.Name);
            }
        }
        catch (Exception e)
        {
            // If one failed, continue trying to update the others.
            exceptions.Add(e);
        }
    }
    foreach (AlertPolicy policy in backup.Policies)
    {
    }
    if (exceptions.Count > 0)
    {
        throw new AggregateException(exceptions);
    }
}

Go

To authenticate to Monitoring, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

// restorePolicies updates the project with the alert policies and
// notification channels in r.
func restorePolicies(w io.Writer, projectID string, r io.Reader) error {
	b := backup{}
	if err := json.NewDecoder(r).Decode(&b); err != nil {
		return err
	}
	sameProject := projectID == b.ProjectID

	ctx := context.Background()

	alertClient, err := monitoring.NewAlertPolicyClient(ctx)
	if err != nil {
		return err
	}
	defer alertClient.Close()
	channelClient, err := monitoring.NewNotificationChannelClient(ctx)
	if err != nil {
		return err
	}
	defer channelClient.Close()

	// When a channel is recreated, rather than updated, it will get
	// a new name.  We have to update the AlertPolicy with the new
	// name.  channelNames keeps track of the new names.
	channelNames := make(map[string]string)
	for _, c := range b.Channels {
		fmt.Fprintf(w, "Updating channel %q\n", c.GetDisplayName())
		c.VerificationStatus = monitoringpb.NotificationChannel_VERIFICATION_STATUS_UNSPECIFIED
		updated := false
		if sameProject {
			req := &monitoringpb.UpdateNotificationChannelRequest{
				NotificationChannel: c.NotificationChannel,
			}
			_, err := channelClient.UpdateNotificationChannel(ctx, req)
			if err == nil {
				updated = true
			}
		}
		if !updated {
			req := &monitoringpb.CreateNotificationChannelRequest{
				Name:                "projects/" + projectID,
				NotificationChannel: c.NotificationChannel,
			}
			oldName := c.GetName()
			c.Name = ""
			newC, err := channelClient.CreateNotificationChannel(ctx, req)
			if err != nil {
				return err
			}
			channelNames[oldName] = newC.GetName()
		}
	}

	for _, policy := range b.AlertPolicies {
		fmt.Fprintf(w, "Updating alert %q\n", policy.GetDisplayName())
		policy.CreationRecord = nil
		policy.MutationRecord = nil
		for i, aChannel := range policy.GetNotificationChannels() {
			if c, ok := channelNames[aChannel]; ok {
				policy.NotificationChannels[i] = c
			}
		}
		updated := false
		if sameProject {
			req := &monitoringpb.UpdateAlertPolicyRequest{
				AlertPolicy: policy.AlertPolicy,
			}
			_, err := alertClient.UpdateAlertPolicy(ctx, req)
			if err == nil {
				updated = true
			}
		}
		if !updated {
			req := &monitoringpb.CreateAlertPolicyRequest{
				Name:        "projects/" + projectID,
				AlertPolicy: policy.AlertPolicy,
			}
			if _, err = alertClient.CreateAlertPolicy(ctx, req); err != nil {
				log.Fatal(err)
			}
		}
	}
	fmt.Fprintf(w, "Successfully restored alerts.")
	return nil
}

Java

To authenticate to Monitoring, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

private static Map<String, String> restoreNotificationChannels(
    String projectId, List<NotificationChannel> channels, boolean isSameProject)
    throws IOException {
  Map<String, String> newChannelNames = Maps.newHashMap();
  try (NotificationChannelServiceClient client = NotificationChannelServiceClient.create()) {
    for (NotificationChannel channel : channels) {
      // Update channel name if project ID is different.
      boolean channelUpdated = false;
      if (isSameProject) {
        try {
          NotificationChannel updatedChannel =
              client.updateNotificationChannel(NOTIFICATION_CHANNEL_UPDATE_MASK, channel);
          newChannelNames.put(channel.getName(), updatedChannel.getName());
          channelUpdated = true;
        } catch (Exception e) {
          channelUpdated = false;
        }
      }
      if (!channelUpdated) {
        NotificationChannel newChannel =
            client.createNotificationChannel(
                ProjectName.of(projectId),
                channel.toBuilder().clearName().clearVerificationStatus().build());
        newChannelNames.put(channel.getName(), newChannel.getName());
      }
    }
  }
  return newChannelNames;
}

Node.js

To authenticate to Monitoring, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

// Imports the Google Cloud client library
const monitoring = require('@google-cloud/monitoring');

// Creates clients
const alertClient = new monitoring.AlertPolicyServiceClient();
const notificationClient = new monitoring.NotificationChannelServiceClient();

async function replaceChannels() {
  /**
   * TODO(developer): Uncomment the following lines before running the sample.
   */
  // const projectId = 'YOUR_PROJECT_ID';
  // const alertPolicyId = '123456789012314';
  // const channelIds = [
  //   'channel-1',
  //   'channel-2',
  //   'channel-3',
  // ];

  const notificationChannels = channelIds.map(id =>
    notificationClient.projectNotificationChannelPath(projectId, id)
  );

  for (const channel of notificationChannels) {
    const updateChannelRequest = {
      updateMask: {
        paths: ['enabled'],
      },
      notificationChannel: {
        name: channel,
        enabled: {
          value: true,
        },
      },
    };
    try {
      await notificationClient.updateNotificationChannel(
        updateChannelRequest
      );
    } catch (err) {
      const createChannelRequest = {
        notificationChannel: {
          name: channel,
          notificationChannel: {
            type: 'email',
          },
        },
      };
      const newChannel =
        await notificationClient.createNotificationChannel(
          createChannelRequest
        );
      notificationChannels.push(newChannel);
    }
  }

  const updateAlertPolicyRequest = {
    updateMask: {
      paths: ['notification_channels'],
    },
    alertPolicy: {
      name: alertClient.projectAlertPolicyPath(projectId, alertPolicyId),
      notificationChannels: notificationChannels,
    },
  };
  const [alertPolicy] = await alertClient.updateAlertPolicy(
    updateAlertPolicyRequest
  );
  console.log(`Updated ${alertPolicy.name}.`);
}
replaceChannels();

PHP

To authenticate to Monitoring, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

use Google\Cloud\Monitoring\V3\Client\NotificationChannelServiceClient;
use Google\Cloud\Monitoring\V3\CreateNotificationChannelRequest;
use Google\Cloud\Monitoring\V3\NotificationChannel;

/**
 * @param string $projectId Your project ID
 */
function alert_create_channel(string $projectId): void
{
    $channelClient = new NotificationChannelServiceClient([
        'projectId' => $projectId,
    ]);
    $projectName = 'projects/' . $projectId;

    $channel = new NotificationChannel();
    $channel->setDisplayName('Test Notification Channel');
    $channel->setType('email');
    $channel->setLabels(['email_address' => '[e-mail]']);
    $createNotificationChannelRequest = (new CreateNotificationChannelRequest())
        ->setName($projectName)
        ->setNotificationChannel($channel);

    $channel = $channelClient->createNotificationChannel($createNotificationChannelRequest);
    printf('Created notification channel %s' . PHP_EOL, $channel->getName());
}

Python

To authenticate to Monitoring, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

def restore(project_name, backup_filename):
    """Restore alert policies in a project.

    Arguments:
        project_name (str): The Google Cloud Project to use. The project name
            must be in the format - 'projects/<PROJECT_NAME>'.
        backup_filename (str): Name of the file (along with its path) from
            which the alert policies will be restored.
    """
    print(
        "Loading alert policies and notification channels from {}.".format(
            backup_filename
        )
    )
    record = json.load(open(backup_filename, "rt"))
    is_same_project = project_name == record["project_name"]
    # Convert dicts to AlertPolicies.
    policies_json = [json.dumps(policy) for policy in record["policies"]]
    policies = [
        monitoring_v3.AlertPolicy.from_json(policy_json)
        for policy_json in policies_json
    ]
    # Convert dicts to NotificationChannels
    channels_json = [json.dumps(channel) for channel in record["channels"]]
    channels = [
        monitoring_v3.NotificationChannel.from_json(channel_json)
        for channel_json in channels_json
    ]

    # Restore the channels.
    channel_client = monitoring_v3.NotificationChannelServiceClient()
    channel_name_map = {}

    for channel in channels:
        updated = False
        print("Updating channel", channel.display_name)
        # This field is immutable and it is illegal to specify a
        # non-default value (UNVERIFIED or VERIFIED) in the
        # Create() or Update() operations.
        channel.verification_status = (
            monitoring_v3.NotificationChannel.VerificationStatus.VERIFICATION_STATUS_UNSPECIFIED
        )

        if is_same_project:
            try:
                channel_client.update_notification_channel(notification_channel=channel)
                updated = True
            except google.api_core.exceptions.NotFound:
                pass  # The channel was deleted.  Create it below.

        if not updated:
            # The channel no longer exists.  Recreate it.
            old_name = channel.name
            del channel.name
            new_channel = channel_client.create_notification_channel(
                name=project_name, notification_channel=channel
            )
            channel_name_map[old_name] = new_channel.name

    # Restore the alerts
    alert_client = monitoring_v3.AlertPolicyServiceClient()

    for policy in policies:
        print("Updating policy", policy.display_name)
        # These two fields cannot be set directly, so clear them.
        del policy.creation_record
        del policy.mutation_record

        # Update old channel names with new channel names.
        for i, channel in enumerate(policy.notification_channels):
            new_channel = channel_name_map.get(channel)
            if new_channel:
                policy.notification_channels[i] = new_channel

        updated = False

        if is_same_project:
            try:
                alert_client.update_alert_policy(alert_policy=policy)
                updated = True
            except google.api_core.exceptions.NotFound:
                pass  # The policy was deleted.  Create it below.
            except google.api_core.exceptions.InvalidArgument:
                # Annoying that API throws InvalidArgument when the policy
                # does not exist.  Seems like it should throw NotFound.
                pass  # The policy was deleted.  Create it below.

        if not updated:
            # The policy no longer exists.  Recreate it.
            old_name = policy.name
            del policy.name
            for condition in policy.conditions:
                del condition.name
            policy = alert_client.create_alert_policy(
                name=project_name, alert_policy=policy
            )
        print("Updated", policy.name)

What's next

To search and filter code samples for other Google Cloud products, see the Google Cloud sample browser.