Create and manage notification channels by API

This document describes how to create and manage notification channels by using client libraries or by using the Google Cloud CLI, both of which invoke the Cloud Monitoring API. Cloud Monitoring uses notification channels to notify you, or your on-call team, when the condition of an alerting policy is met. There are several available channel types; each type is described in a notification-channel descriptor. A notification channel of a certain type is an instance of that type's descriptor. Your alerting policies include references to the notification channels to use as notification pathways.

A notification channel must exist before it can be used in an alerting policy. The notification-channel descriptors are provided to you, but you have to create the channels before they can be used.

To configure notification channels by using the Google Cloud console, see Create and manage notification channels.

The code samples used in this document are extracted from the alerting-policy API example, described in Example: backup and restore.

About the API

The NotificationChannel resource supports operations that let you manage your notification channels. It also supports operations related to managing the verificationStatus field of a channel:

Sending a verification code
Generating a code for copying the verification status of a verified channel to other identical channels in the same or a new project
Verifying the channel using the code created by the previous two operations

For more information, see the notificationChannels reference documents.

Before you begin

To get the permissions that you need to view and configure notification channels by using the Cloud Monitoring API, ask your administrator to grant you the Monitoring NotificationChannel Editor (roles/monitoring.notificationChannelEditor) IAM role on your project. For more information about granting roles, see Manage access to projects, folders, and organizations.

You might also be able to get the required permissions through custom roles or other predefined roles.

For more information about Cloud Monitoring roles, see Control access with Identity and Access Management.

List the types of notification channels

Monitoring provides a number of built-in notification-channel types. Each of these types is described in a NotificationChannelDescriptor. These descriptors have a type field, and the value of this field acts as an identifier for it when creating instances of that channel type. To retrieve a list of channel types that you can create with the Cloud Monitoring API or the Google Cloud CLI, enter the following command:

$ gcloud beta monitoring channel-descriptors list --format='value(type)'
campfire
email
google_chat
hipchat
pagerduty
pubsub
slack
sms
webhook_basicauth
webhook_tokenauth

For more information about notification channels, see Create and manage notification channels.

If your preferred notification channel isn't supported, consider creating a pipeline that relies on sending your notifications to Pub/Sub. For a Python example that uses Flask, see Creating custom notifications with Cloud Monitoring and Cloud Run. For other examples, see the cloud-alerting-notification-forwarding Git repository.

To retrieve all the channel descriptors in a Google Cloud project, use the notificationChannelDescriptors.list method. The retrieved descriptors are read-only.

If you are looking for a specific descriptor and you know its name, you can use the notificationChannelDescriptors.get method to retrieve only that channel descriptor. The name of a channel descriptor has the format projects/[PROJECT_ID]/notificationChannelDescriptors/[CHANNEL_TYPE] [CHANNEL_TYPE] must be one of the types listed above, for example:

projects/[PROJECT_ID]/notificationChannelDescriptors/email

gcloud

To list all the notification-channel descriptors in a Google Cloud project, use the gcloud beta monitoring channel-descriptors list command:

gcloud beta monitoring channel-descriptors list

If successful, the list command provides a listing of all the channel descriptors in the specified project. For example, the email channel descriptor appears in the list like this:

    ---
    description: A channel that sends notifications via email.
    displayName: Email
    labels:
    - description: An address to send email.
      key: email_address
    name: projects/[PROJECT_ID]/notificationChannelDescriptors/email
    type: email
    ---

All channel descriptors include these fields:

name: The fully qualified resource name of the channel descriptor
type: The part of the name that indicates the type of channel
displayName: A description of the type field, for display purposes
description: A brief description of the channel
labels: A set of fields specific to a channel type. Each channel type has its own set of labels.

When a channel is created, it also gets an enabled field, with the value true by default.

To list a single channel descriptor, use gcloud beta monitoring channel-descriptors describe, instead, and specify the name of the channel descriptor. You don't need to specify the fully qualified name. For example, both of these commands return the listing above:

gcloud beta monitoring channel-descriptors describe email

gcloud beta monitoring channel-descriptors describe projects/[PROJECT_ID]/notificationChannelDescriptors/email

See the gcloud beta monitoring channel-descriptors list and describe references for more information. The describe command corresponds to the notificationChannelDescriptors.get method in the API.

Create a notification channel

You can create notification channels for your Google Cloud projects from JSON or YAML files by using the Google Cloud CLI, and you can create them programmatically.

To create a notification channel, you must supply values for the fields in its descriptor. Most of these, like type, are common across all notification-channel descriptors; see notificationChannelDescriptors.

Each descriptor also has a set of labels, and this set varies across the descriptors. To see the set of labels for a particular descriptor, retrieve the descriptor using the gcloud beta monitoring channel-descriptors describe command described in List the types of notification channels. For example, retrieving the email channel descriptor shows a single label:

    labels:
    - description: An address to send email.
      key: email_address

The pubsub channel descriptor also contains a single label; that label identifies the Pub/Sub topic. However, channels can contain multiple labels. For example, the slack channel descriptor has two labels:

    labels:
    - description: A permanent authentication token provided by Slack. This field is obfuscated by returning only a few characters of the key when fetched.
      key: auth_token
    - description: The Slack channel to which to post notifications.
      key: channel_name

Retrieving the webhook_basicauth channel descriptor shows several labels:

    labels:
    - description: The password. The field is obfuscated when the channel is fetched.
      key: password
    - description: The public URL to which to publish the webhook.
      key: url
    - description: The username.
      key: username

Whether you create a new channel programmatically or from the command line, the value of the type in your specification must match the type field in the corresponding notification-channel descriptor. Any required label keys must also match those in the channel descriptor.

Some labels correspond to credentials used to authenticate with the provider. When creating a channel, the values for these labels must be obtained from the provider. Obtaining a credential might involve using an API key-generation page on the provider's website or completing an OAuth login flow with the provider. The specifics of how to obtain such a credential depend on the particular provider.

For example, the following shows the specification of a new pubsub notification channel in JSON:

    {
      "type": "pubsub",
      "displayName": "Notifications",
      "description": "Pub/Sub channel for notifications",
      "labels": {
        "topic": "projects/[PROJECT_ID]/topics/notificationTopic"
      },
    }

The type value (pubsub) and the single label key (topic) match the type and labels.key fields in the corresponding channel descriptor.

Channels are enabled by default. If you want to create an inactive channel, you can include the field enabled with the value false.

The following examples illustrate the creation of notification channels.

gcloud

To create a notification channel in a Google Cloud project, use the gcloud beta monitoring channels create command. To load the channel from a file, use the --channel-content-from-file flag to specify the file.

The following example creates a new Pub/Sub channel from the pubsub-channel.json file:

gcloud beta monitoring channels create --channel-content-from-file="pubsub-channel.json"

If successful, this command returns the name of the new channel, for example:

    Created notification channel [projects/[PROJECT_ID]/notificationChannels/1355376463305411567].

See the gcloud beta monitoring channels create reference for more information.

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);
    }
}

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();

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;
}

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' => 'fake@example.com']);
    $createNotificationChannelRequest = (new CreateNotificationChannelRequest())
        ->setName($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)

Example: Create a Slack notification channel

To configure a notification channel for a Slack app, do the following:

Configure your Slack app:
1. If you don't already have a Slack app, follow the Slack reference documentation to create one and install it to your workspace.
2. Configure your Slack app with OAuth scopes for chat:write and chat:write.public.
3. Copy the app's Bot User OAuth token.

Create a file that defines the configuration of your notification channel. Include a label where the auth_token key has the value of your Slack app's Bot User OAuth token. For example:

{
  "description": "A Slack notification channel",
  "displayName": "Slack",
  "type": "slack",
  "enabled": true,
  "labels": {
    "auth_token": "OAUTH_TOKEN_VALUE",
    "channel_name": "SLACK_CHANNEL_NAME"
  }
}

Run the following command to create the notification channel:

gcloud beta monitoring channels create --channel-content-from-file="FILE_NAME"

List notification channels in a project

To retrieve all the notification channels in a Google Cloud project, use the notificationChannels.list method. This method also supports filter and orderBy options to restrict and sort the results; see Sorting and Filtering.

If you are looking for a specific channel and you know its name, you can use the notificationChannels.get method to retrieve only that channel. The name of a channel has the format projects/[PROJECT_ID]/notificationChannels/[CHANNEL_ID], for example:

    projects/[PROJECT_ID]/notificationChannels/1355376463305411567

When you retrieve a channel, sensitive values like authentication tokens and API keys might be obfuscated for security reasons. If you are creating a new channel by copying an existing one, any obfuscated values need to be corrected.

gcloud

To list all the notification channels in a Google Cloud project, use the gcloud beta monitoring channels list command:

gcloud beta monitoring channels list

If successful, the list command provides a listing of all the channels in the specified project. For example, the command above might return a list that includes the following entries:

    ---
    description: E-mail channel created by gcloud as a test
    displayName: test e-mail channel
    enabled: false
    labels:
      email_address: user@example.com
    name: projects/[PROJECT_ID]/notificationChannels/1355376463305411567
    type: email
    ---
    description: Pub/Sub channel for notifications
    displayName: Notifications
    enabled: true
    labels:
      topic: projects/[PROJECT_ID]/topics/notificationTopic
    name: projects/[PROJECT_ID]/notificationChannels/1355376463305411567
    type: pubsub

To list a single channel, use gcloud beta monitoring channels describe, instead, and specify the name of the channel. For example, this command returns the Pub/Sub channel shown in the listing above:

gcloud beta monitoring channels describe projects/[PROJECT_ID]/notificationChannels/1355376463305411567

See the gcloud beta monitoring channels list and describe references for more information. The describe command corresponds to the notificationChannels.get method in the API.

C#

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

static void ListNotificationChannels(string projectId)
{
    var client = NotificationChannelServiceClient.Create();
    var response = client.ListNotificationChannels(new ProjectName(projectId));
    foreach (NotificationChannel channel in response)
    {
        Console.WriteLine(channel.Name);
        if (channel.DisplayName != null)
        {
            Console.WriteLine(channel.DisplayName);
        }
        Console.WriteLine();
    }
}

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 a client
const client = new monitoring.NotificationChannelServiceClient();

async function deleteChannels() {
  /**
   * TODO(developer): Uncomment the following lines before running the sample.
   */
  // const projectId = 'YOUR_PROJECT_ID';
  // const filter = 'A filter for selecting policies, e.g. description:"cloud"';

  const request = {
    name: client.projectPath(projectId),
    filter,
  };
  const channels = await client.listNotificationChannels(request);
  console.log(channels);
  for (const channel of channels[0]) {
    console.log(`Deleting channel ${channel.displayName}`);
    try {
      await client.deleteNotificationChannel({
        name: channel.name,
      });
    } catch (err) {
      // ignore error
    }
  }
}
deleteChannels();

Go

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

channelClient, err := monitoring.NewNotificationChannelClient(ctx)
if err != nil {
	return err
}
defer channelClient.Close()
channelReq := &monitoringpb.ListNotificationChannelsRequest{
	Name: "projects/" + projectID,
	// Filter:  "", // See https://cloud.google.com/monitoring/api/v3/sorting-and-filtering.
	// OrderBy: "", // See https://cloud.google.com/monitoring/api/v3/sorting-and-filtering.
}
channelIt := channelClient.ListNotificationChannels(ctx, channelReq)
for {
	resp, err := channelIt.Next()
	if err == iterator.Done {
		break
	}
	if err != nil {
		return err
	}
	b.Channels = append(b.Channels, &channel{resp})
}

Java

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

private static List<NotificationChannel> getNotificationChannels(String projectId)
    throws IOException {
  List<NotificationChannel> notificationChannels = Lists.newArrayList();
  try (NotificationChannelServiceClient client = NotificationChannelServiceClient.create()) {
    ListNotificationChannelsPagedResponse listNotificationChannelsResponse =
        client.listNotificationChannels(ProjectName.of(projectId));
    for (NotificationChannel channel : listNotificationChannelsResponse.iterateAll()) {
      notificationChannels.add(channel);
    }
  }
  return notificationChannels;
}

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\ListNotificationChannelsRequest;

/**
 * @param string $projectId Your project ID
 */
function alert_list_channels($projectId)
{
    $projectName = 'projects/' . $projectId;
    $channelClient = new NotificationChannelServiceClient([
        'projectId' => $projectId,
    ]);
    $listNotificationChannelsRequest = (new ListNotificationChannelsRequest())
        ->setName($projectName);

    $channels = $channelClient->listNotificationChannels($listNotificationChannelsRequest);
    foreach ($channels->iterateAllElements() as $channel) {
        printf('Name: %s (%s)' . PHP_EOL, $channel->getDisplayName(), $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 list_notification_channels(project_name):
    """List alert notification channels in a project.

    Arguments:
        project_name (str): The Google Cloud Project to use. The project name
            must be in the format - 'projects/<PROJECT_NAME>'.
    """

    client = monitoring_v3.NotificationChannelServiceClient()
    channels = client.list_notification_channels(name=project_name)
    print(
        tabulate.tabulate(
            [(channel.name, channel.display_name) for channel in channels],
            ("name", "display_name"),
        )
    )

Delete a notification channel from a project

To delete a notification channel from a Google Cloud project, use the notificationChannels.delete method, and supply the name of the notification channel to delete. The name of a channel is the value of the name field, not the displayName, in the NotificationChannel instance. The name of a channel has the format projects/[PROJECT_ID]/notificationChannels/[CHANNEL_ID], for example:

    projects/[PROJECT_ID]/notificationChannels/1355376463305411567

By default, if you attempt to delete a channel that is referenced by an alerting policy, then the channel won't be deleted. To force the removal of references from alerting policies and delete the channel, set the force option to true. This option automatically removes the channel from all referencing policies.

gcloud

To delete a notification channel, use gcloud beta monitoring channels delete, and specify the name of the channel to delete. For example, the following command deletes the email channel created in another example:

gcloud beta monitoring channels delete projects/[PROJECT_ID]/notificationChannels/1355376463305411567

See the gcloud beta monitoring channels delete reference for more information.

C#

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


using Google.Cloud.Monitoring.V3;
using System;

partial class AlertSnippets
{
    public void DeleteNotificationChannel(
        string channelName = "projects/your-project-id/notificationChannels/123")
    {
        var client = NotificationChannelServiceClient.Create();
        client.DeleteNotificationChannel(
            name: NotificationChannelName.Parse(channelName),
            force: true);
        Console.WriteLine("Deleted {0}.", channelName);
    }
}

Go

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


import (
	"context"
	"fmt"
	"io"

	monitoring "cloud.google.com/go/monitoring/apiv3"
	"cloud.google.com/go/monitoring/apiv3/v2/monitoringpb"
)

// deleteChannel deletes the given channel. channelName should be of the form
// "projects/[PROJECT_ID]/notificationChannels/[CHANNEL_ID]".
func deleteChannel(w io.Writer, channelName string) error {
	ctx := context.Background()

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

	req := &monitoringpb.DeleteNotificationChannelRequest{
		Name: channelName,
	}

	if err := client.DeleteNotificationChannel(ctx, req); err != nil {
		return fmt.Errorf("DeleteNotificationChannel: %w", err)
	}

	fmt.Fprintf(w, "Deleted channel %q", channelName)
	return nil
}

Java

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

static void deleteNotificationChannel(String channelName) throws IOException {
  String projectId = System.getProperty("projectId");
  try (NotificationChannelServiceClient client = NotificationChannelServiceClient.create()) {
    NotificationChannelName name = NotificationChannelName.of(projectId, channelName);
    client.deleteNotificationChannel(channelName, false);
    System.out.println("Deleted notification channel " + channelName);
  }
}

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\DeleteNotificationChannelRequest;

/**
 * @param string $projectId Your project ID
 * @param string $channelId
 */
function alert_delete_channel(string $projectId, string $channelId): void
{
    $channelClient = new NotificationChannelServiceClient([
        'projectId' => $projectId,
    ]);
    $channelName = $channelClient->notificationChannelName($projectId, $channelId);
    $deleteNotificationChannelRequest = (new DeleteNotificationChannelRequest())
        ->setName($channelName);

    $channelClient->deleteNotificationChannel($deleteNotificationChannelRequest);
    printf('Deleted notification channel %s' . PHP_EOL, $channelName);
}

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 a client
const client = new monitoring.NotificationChannelServiceClient();

async function deleteChannels() {
  /**
   * TODO(developer): Uncomment the following lines before running the sample.
   */
  // const projectId = 'YOUR_PROJECT_ID';
  // const filter = 'A filter for selecting policies, e.g. description:"cloud"';

  const request = {
    name: client.projectPath(projectId),
    filter,
  };
  const channels = await client.listNotificationChannels(request);
  console.log(channels);
  for (const channel of channels[0]) {
    console.log(`Deleting channel ${channel.displayName}`);
    try {
      await client.deleteNotificationChannel({
        name: channel.name,
      });
    } catch (err) {
      // ignore error
    }
  }
}
deleteChannels();

Python

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

def delete_notification_channels(project_name, channel_ids, force=None):
    """Delete alert notification channels.

    Arguments:
        project_name (str): The Google Cloud Project to use. The project name
            must be in the format - 'projects/<PROJECT_NAME>'.
        channel_ids list(str): List of IDs of notification channels to delete.
        force (bool): If true, the notification channels are deleted regardless
            of its in use by alert policies. If false, channels that are still
            referenced by an existing alerting policy will fail to be deleted.
    """

    channel_client = monitoring_v3.NotificationChannelServiceClient()
    for channel_id in channel_ids:
        channel_name = "{}/notificationChannels/{}".format(project_name, channel_id)
        try:
            channel_client.delete_notification_channel(name=channel_name, force=force)
            print("Channel {} deleted".format(channel_name))
        except ValueError:
            print("The parameters are invalid")
        except Exception as e:
            print("API call failed: {}".format(e))

Modify a notification channel

To modify a notification channel, use the notificationChannels.patch method (in the REST API). Other API implementations and the Google Cloud CLI call this update instead of patch.

An update operation can wholly replace the existing channel, or it can modify a subset of fields. For example, you can enable and disable the channel. Disabling a channel prevents delivery of notifications to the channel. Disabling a channel is typically more convenient than removing the channel from the alerting policies that refer to it, if the change is intended to be temporary.

gcloud

To enable a notification channel that is disabled, use the gcloud beta monitoring channels update command, and provide the --enabled flag. The following command enables the email notification channel created—in the disabled state—in a previous example:

gcloud beta monitoring channels update projects/[PROJECT_ID]/notificationChannels/1355376463305411567 --enabled

To disable a policy, use the same command and provide the --no-enabled flag. See the gcloud beta monitoring channels update reference for more information. The update command corresponds to the notificationChannels.patch method in the REST API.

C#

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


using Google.Cloud.Monitoring.V3;
using Google.Protobuf.WellKnownTypes;
using System;

partial class AlertSnippets
{
    public NotificationChannel EnableNotificationChannel(
        string channelName = "projects/your-project-id/notificationChannels/123")
    {
        var client = NotificationChannelServiceClient.Create();
        NotificationChannel channel = new NotificationChannel();
        channel.Enabled = true;
        channel.Name = channelName;
        var fieldMask = new FieldMask { Paths = { "enabled" } };
        channel = client.UpdateNotificationChannel(
            updateMask: fieldMask,
            notificationChannel: channel);
        Console.WriteLine("Enabled {0}.", channel.Name);
        return channel;
    }
}

Go

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


import (
	"context"
	"fmt"
	"io"

	monitoring "cloud.google.com/go/monitoring/apiv3"
	"cloud.google.com/go/monitoring/apiv3/v2/monitoringpb"
	"github.com/golang/protobuf/ptypes/wrappers"
	"google.golang.org/genproto/protobuf/field_mask"
)

// enableChannel enables the given channel. channelName should be of the form
// "projects/[PROJECT_ID]/notificationChannels/[CHANNEL_ID]".
func enableChannel(w io.Writer, channelName string) error {
	ctx := context.Background()

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

	req := &monitoringpb.UpdateNotificationChannelRequest{
		UpdateMask: &field_mask.FieldMask{Paths: []string{"enabled"}},
		NotificationChannel: &monitoringpb.NotificationChannel{
			Name:    channelName,
			Enabled: &wrappers.BoolValue{Value: true},
		},
	}

	if _, err := client.UpdateNotificationChannel(ctx, req); err != nil {
		return fmt.Errorf("EnableNotificationChannel: %w", err)
	}

	fmt.Fprintf(w, "Enabled channel %q", channelName)
	return nil
}

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();

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;
}

PHP

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

use Google\ApiCore\ApiException;
use Google\Cloud\Monitoring\V3\AlertPolicy;
use Google\Cloud\Monitoring\V3\Client\AlertPolicyServiceClient;
use Google\Cloud\Monitoring\V3\Client\NotificationChannelServiceClient;
use Google\Cloud\Monitoring\V3\CreateAlertPolicyRequest;
use Google\Cloud\Monitoring\V3\CreateNotificationChannelRequest;
use Google\Cloud\Monitoring\V3\NotificationChannel;
use Google\Cloud\Monitoring\V3\NotificationChannel\VerificationStatus;
use Google\Cloud\Monitoring\V3\UpdateAlertPolicyRequest;
use Google\Cloud\Monitoring\V3\UpdateNotificationChannelRequest;

/**
 * @param string $projectId Your project ID
 */
function alert_restore_policies(string $projectId): void
{
    $alertClient = new AlertPolicyServiceClient([
        'projectId' => $projectId,
    ]);

    $channelClient = new NotificationChannelServiceClient([
        'projectId' => $projectId,
    ]);

    print('Loading alert policies and notification channels from backup.json.' . PHP_EOL);
    $projectName = 'projects/' . $projectId;
    $record = json_decode((string) file_get_contents('backup.json'), true);
    $isSameProject = $projectName == $record['project_name'];

    # Convert dicts to AlertPolicies.
    $policies = [];
    foreach ($record['policies'] as $policyArray) {
        $policy = new AlertPolicy();
        $policy->mergeFromJsonString((string) json_encode($policyArray));
        $policies[] = $policy;
    }

    # Convert dicts to NotificationChannels
    $channels = [];
    foreach (array_filter($record['channels']) as $channelArray) {
        $channel = new NotificationChannel();
        $channel->mergeFromJsonString((string) json_encode($channelArray));
        $channels[] = $channel;
    }

    # Restore the channels.
    $channelNameMap = [];
    foreach ($channels as $channel) {
        $updated = false;
        printf('Updating channel %s' . PHP_EOL, $channel->getDisplayName());

        # This field is immutable and it is illegal to specify a
        # non-default value (UNVERIFIED or VERIFIED) in the
        # Create() or Update() operations.
        $channel->setVerificationStatus(
            VerificationStatus::VERIFICATION_STATUS_UNSPECIFIED
        );

        if ($isSameProject) {
            try {
                $updateNotificationChannelRequest = (new UpdateNotificationChannelRequest())
                    ->setNotificationChannel($channel);
                $channelClient->updateNotificationChannel($updateNotificationChannelRequest);
                $updated = true;
            } catch (ApiException $e) {
                # The channel was deleted.  Create it below.
                if ($e->getStatus() !== 'NOT_FOUND') {
                    throw $e;
                }
            }
        }

        if (!$updated) {
            # The channel no longer exists.  Recreate it.
            $oldName = $channel->getName();
            $channel->setName('');
            $createNotificationChannelRequest = (new CreateNotificationChannelRequest())
                ->setName($projectName)
                ->setNotificationChannel($channel);
            $newChannel = $channelClient->createNotificationChannel($createNotificationChannelRequest);
            $channelNameMap[$oldName] = $newChannel->getName();
        }
    }

    # Restore the alerts
    foreach ($policies as $policy) {
        printf('Updating policy %s' . PHP_EOL, $policy->getDisplayName());
        # These two fields cannot be set directly, so clear them.
        $policy->clearCreationRecord();
        $policy->clearMutationRecord();

        $notificationChannels = $policy->getNotificationChannels();

        # Update old channel names with new channel names.
        foreach ($notificationChannels as $i => $channel) {
            if (isset($channelNameMap[$channel])) {
                $notificationChannels[$i] = $channelNameMap[$channel];
            }
        }

        $updated = false;
        if ($isSameProject) {
            try {
                $updateAlertPolicyRequest = (new UpdateAlertPolicyRequest())
                    ->setAlertPolicy($policy);
                $alertClient->updateAlertPolicy($updateAlertPolicyRequest);
                $updated = true;
            } catch (ApiException $e) {
                # The policy was deleted.  Create it below.
                if ($e->getStatus() !== 'NOT_FOUND') {
                    throw $e;
                }
            }
        }

        if (!$updated) {
            # The policy no longer exists.  Recreate it.
            $oldName = $policy->getName();
            $policy->setName('');
            foreach ($policy->getConditions() as $condition) {
                $condition->setName('');
            }
            $createAlertPolicyRequest = (new CreateAlertPolicyRequest())
                ->setName($projectName)
                ->setAlertPolicy($policy);
            $policy = $alertClient->createAlertPolicy($createAlertPolicyRequest);
        }
        printf('Updated %s' . PHP_EOL, $policy->getName());
    }
    print('Restored alert policies and notification channels from backup.json.');
}

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)

View notification channel logs

You can use the Logs Explorer to view notification channel errors:

In the Google Cloud console, go to the Logs Explorer page:
Go to Logs Explorer

If you use the search bar to find this page, then select the result whose subheading is Logging.
Enter and run your query. For queries specific to notification channel errors, see Cloud Monitoring queries.