Manage alerting policies by API

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)
    {
    }
    foreach (AlertPolicy policy in backup.Policies)
    {
        string policyName = policy.Name;
        // These two fields cannot be set directly, so clear them.
        policy.CreationRecord = null;
        policy.MutationRecord = null;
        // Update channel names if the channel was recreated with
        // another name.
        for (int i = 0; i < policy.NotificationChannels.Count; ++i)
        {
            if (channelNameMap.ContainsKey(policy.NotificationChannels[i]))
            {
                policy.NotificationChannels[i] =
                    channelNameMap[policy.NotificationChannels[i]];
            }
        }
        try
        {
            Console.WriteLine("Updating policy.\n{0}",
                policy.DisplayName);
            bool updated = false;
            if (isSameProject)
                try
                {
                    policyClient.UpdateAlertPolicy(null, policy);
                    updated = true;
                }
                catch (Grpc.Core.RpcException e)
                when (e.Status.StatusCode == StatusCode.NotFound)
                { }
            if (!updated)
            {
                // The policy no longer exists.  Recreate it.
                policy.Name = null;
                foreach (var condition in policy.Conditions)
                {
                    condition.Name = null;
                }
                policyClient.CreateAlertPolicy(projectName, policy);
            }
            Console.WriteLine("Restored {0}.", policyName);
        }
        catch (Exception e)
        {
            // If one failed, continue trying to update the others.
            exceptions.Add(e);
        }
    }
    if (exceptions.Count > 0)
    {
        throw new AggregateException(exceptions);
    }
}

// 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
}

private static void restoreRevisedPolicies(
    String projectId, boolean isSameProject, List<AlertPolicy> policies) throws IOException {
  try (AlertPolicyServiceClient client = AlertPolicyServiceClient.create()) {
    for (AlertPolicy policy : policies) {
      if (!isSameProject) {
        policy = client.createAlertPolicy(ProjectName.of(projectId), policy);
      } else {
        try {
          client.updateAlertPolicy(null, policy);
        } catch (Exception e) {
          policy =
              client.createAlertPolicy(
                  ProjectName.of(projectId), policy.toBuilder().clearName().build());
        }
      }
      System.out.println(String.format("Restored %s", policy.getName()));
    }
  }
}

const fs = require('fs');

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

// Creates a client
const client = new monitoring.AlertPolicyServiceClient();

async function restorePolicies() {
  // Note: The policies are restored one at a time due to limitations in
  // the API. Otherwise, you may receive a 'service unavailable'  error
  // while trying to create multiple alerts simultaneously.

  /**
   * TODO(developer): Uncomment the following lines before running the sample.
   */
  // const projectId = 'YOUR_PROJECT_ID';

  console.log('Loading policies from ./policies_backup.json');
  const fileContent = fs.readFileSync('./policies_backup.json', 'utf-8');
  const policies = JSON.parse(fileContent);

  for (const index in policies) {
    // Restore each policy one at a time
    let policy = policies[index];
    if (await doesAlertPolicyExist(policy.name)) {
      policy = await client.updateAlertPolicy({
        alertPolicy: policy,
      });
    } else {
      // Clear away output-only fields
      delete policy.name;
      delete policy.creationRecord;
      delete policy.mutationRecord;
      policy.conditions.forEach(condition => delete condition.name);

      policy = await client.createAlertPolicy({
        name: client.projectPath(projectId),
        alertPolicy: policy,
      });
    }

    console.log(`Restored ${policy[0].name}.`);
  }
  async function doesAlertPolicyExist(name) {
    try {
      const [policy] = await client.getAlertPolicy({
        name,
      });
      return policy ? true : false;
    } catch (err) {
      if (err && err.code === 5) {
        // Error code 5 comes from the google.rpc.code.NOT_FOUND protobuf
        return false;
      }
      throw err;
    }
  }
}
restorePolicies();

use Google\Cloud\Monitoring\V3\AlertPolicy;
use Google\Cloud\Monitoring\V3\AlertPolicy\Condition;
use Google\Cloud\Monitoring\V3\AlertPolicy\Condition\MetricThreshold;
use Google\Cloud\Monitoring\V3\AlertPolicy\ConditionCombinerType;
use Google\Cloud\Monitoring\V3\Client\AlertPolicyServiceClient;
use Google\Cloud\Monitoring\V3\ComparisonType;
use Google\Cloud\Monitoring\V3\CreateAlertPolicyRequest;
use Google\Protobuf\Duration;

/**
 * @param string $projectId Your project ID
 */
function alert_create_policy($projectId)
{
    $alertClient = new AlertPolicyServiceClient([
        'projectId' => $projectId,
    ]);
    $projectName = 'projects/' . $projectId;

    $policy = new AlertPolicy();
    $policy->setDisplayName('Test Alert Policy');
    $policy->setCombiner(ConditionCombinerType::PBOR);
    /** @see https://cloud.google.com/monitoring/api/resources for a list of resource.type */
    /** @see https://cloud.google.com/monitoring/api/metrics_gcp for a list of metric.type */
    $policy->setConditions([new Condition([
        'display_name' => 'condition-1',
        'condition_threshold' => new MetricThreshold([
            'filter' => 'resource.type = "gce_instance" AND metric.type = "compute.googleapis.com/instance/cpu/utilization"',
            'duration' => new Duration(['seconds' => '60']),
            'comparison' => ComparisonType::COMPARISON_LT,
        ])
    ])]);
    $createAlertPolicyRequest = (new CreateAlertPolicyRequest())
        ->setName($projectName)
        ->setAlertPolicy($policy);

    $policy = $alertClient->createAlertPolicy($createAlertPolicyRequest);
    printf('Created alert policy %s' . PHP_EOL, $policy->getName());
}

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)

static void ListAlertPolicies(string projectId)
{
    var client = AlertPolicyServiceClient.Create();
    var response = client.ListAlertPolicies(new ProjectName(projectId));
    foreach (AlertPolicy policy in response)
    {
        Console.WriteLine(policy.Name);
        if (policy.DisplayName != null)
        {
            Console.WriteLine(policy.DisplayName);
        }
        if (policy.Documentation?.Content != null)
        {
            Console.WriteLine(policy.Documentation.Content);
        }
        Console.WriteLine();
    }
}

// listAlertPolicies lists the alert policies in the project.
func listAlertPolicies(w io.Writer, projectID string) error {
	ctx := context.Background()
	client, err := monitoring.NewAlertPolicyClient(ctx)
	if err != nil {
		return err
	}
	defer client.Close()

	req := &monitoringpb.ListAlertPoliciesRequest{
		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.
	}
	it := client.ListAlertPolicies(ctx, req)
	for {
		resp, err := it.Next()
		if err == iterator.Done {
			fmt.Fprintln(w, "Done")
			break
		}
		if err != nil {
			return err
		}
		fmt.Fprintf(w, "  Name: %q\n", resp.GetName())
		fmt.Fprintf(w, "  Display Name: %q\n", resp.GetDisplayName())
		fmt.Fprintf(w, "  Documentation Content: %q\n\n", resp.GetDocumentation().GetContent())
	}
	return nil
}

private static void listAlertPolicies(String projectId) throws IOException {
  try (AlertPolicyServiceClient client = AlertPolicyServiceClient.create()) {
    ListAlertPoliciesPagedResponse response = client.listAlertPolicies(ProjectName.of(projectId));

    System.out.println("Alert Policies:");
    for (AlertPolicy policy : response.iterateAll()) {
      System.out.println(
          String.format("\nPolicy %s\nalert-id: %s", policy.getDisplayName(), policy.getName()));
      int channels = policy.getNotificationChannelsCount();
      if (channels > 0) {
        System.out.println("notification-channels:");
        for (int i = 0; i < channels; i++) {
          System.out.println("\t" + policy.getNotificationChannels(i));
        }
      }
      if (policy.hasDocumentation() && policy.getDocumentation().getContent() != null) {
        System.out.println(policy.getDocumentation().getContent());
      }
    }
  }
}

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

// Creates a client
const client = new monitoring.AlertPolicyServiceClient();

async function listPolicies() {
  /**
   * TODO(developer): Uncomment the following lines before running the sample.
   */
  // const projectId = 'YOUR_PROJECT_ID';

  const listAlertPoliciesRequest = {
    name: client.projectPath(projectId),
  };
  const [policies] = await client.listAlertPolicies(listAlertPoliciesRequest);
  console.log('Policies:');
  policies.forEach(policy => {
    console.log(`  Display name: ${policy.displayName}`);
    if (policy.documentation && policy.documentation.content) {
      console.log(`     Documentation: ${policy.documentation.content}`);
    }
  });
}
listPolicies();

use Google\Cloud\Monitoring\V3\Client\AlertPolicyServiceClient;
use Google\Cloud\Monitoring\V3\ListAlertPoliciesRequest;

/**
 * Adds a new column to the Albums table in the example database.
 * Example:
 * ```
 * alert_list_policies($projectId);
 * ```
 *
 * @param string $projectId Your project ID
 */
function alert_list_policies($projectId)
{
    $projectName = 'projects/' . $projectId;
    $alertClient = new AlertPolicyServiceClient([
        'projectId' => $projectId,
    ]);
    $listAlertPoliciesRequest = (new ListAlertPoliciesRequest())
        ->setName($projectName);

    $policies = $alertClient->listAlertPolicies($listAlertPoliciesRequest);
    foreach ($policies->iterateAllElements() as $policy) {
        printf('Name: %s (%s)' . PHP_EOL, $policy->getDisplayName(), $policy->getName());
    }
}

def list_alert_policies(project_name):
    """List 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>'.
    """

    client = monitoring_v3.AlertPolicyServiceClient()
    policies = client.list_alert_policies(name=project_name)
    print(
        str(
            tabulate.tabulate(
                [(policy.name, policy.display_name) for policy in policies],
                ("name", "display_name"),
            )
        )
    )

static object EnablePolicies(string projectId, string filter, bool enable)
{
    var client = AlertPolicyServiceClient.Create();
    var request = new ListAlertPoliciesRequest()
    {
        ProjectName = new ProjectName(projectId),
        Filter = filter
    };
    var response = client.ListAlertPolicies(request);
    int result = 0;
    foreach (AlertPolicy policy in response)
    {
        try
        {
            if (policy.Enabled == enable)
            {
                Console.WriteLine("Policy {0} is already {1}.",
                    policy.Name, enable ? "enabled" : "disabled");
                continue;
            }
            policy.Enabled = enable;
            var fieldMask = new FieldMask { Paths = { "enabled" } };
            client.UpdateAlertPolicy(fieldMask, policy);
            Console.WriteLine("{0} {1}.", enable ? "Enabled" : "Disabled",
                policy.Name);
        }
        catch (Grpc.Core.RpcException e)
        when (e.Status.StatusCode == StatusCode.InvalidArgument)
        {
            Console.WriteLine(e.Message);
            result -= 1;
        }
    }
    // Return a negative count of how many enable operations failed.
    return result;
}

// enablePolicies enables or disables all alert policies in the project.
func enablePolicies(w io.Writer, projectID string, enable bool) error {
	ctx := context.Background()

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

	req := &monitoringpb.ListAlertPoliciesRequest{
		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.
	}
	it := client.ListAlertPolicies(ctx, req)
	for {
		a, err := it.Next()
		if err == iterator.Done {
			break
		}
		if err != nil {
			return err
		}
		if a.GetEnabled().GetValue() == enable {
			fmt.Fprintf(w, "Policy %q already has enabled=%v", a.GetDisplayName(), enable)
			continue
		}
		a.Enabled = &wrappers.BoolValue{Value: enable}
		req := &monitoringpb.UpdateAlertPolicyRequest{
			AlertPolicy: a,
			UpdateMask: &fieldmask.FieldMask{
				Paths: []string{"enabled"},
			},
		}
		if _, err := client.UpdateAlertPolicy(ctx, req); err != nil {
			return err
		}
	}
	fmt.Fprintln(w, "Successfully updated alerts.")
	return nil
}

private static void enablePolicies(String projectId, String filter, boolean enable)
    throws IOException {
  try (AlertPolicyServiceClient client = AlertPolicyServiceClient.create()) {
    ListAlertPoliciesPagedResponse response =
        client.listAlertPolicies(
            ListAlertPoliciesRequest.newBuilder()
                .setName(ProjectName.of(projectId).toString())
                .setFilter(filter)
                .build());

    for (AlertPolicy policy : response.iterateAll()) {
      if (policy.getEnabled().getValue() == enable) {
        System.out.println(
            String.format(
                "Policy %s is already %b.", policy.getName(), enable ? "enabled" : "disabled"));
        continue;
      }
      AlertPolicy updatedPolicy =
          AlertPolicy.newBuilder()
              .setName(policy.getName())
              .setEnabled(BoolValue.newBuilder().setValue(enable))
              .build();
      AlertPolicy result =
          client.updateAlertPolicy(
              FieldMask.newBuilder().addPaths("enabled").build(), updatedPolicy);
      System.out.println(
          String.format(
              "%s %s",
              result.getDisplayName(), result.getEnabled().getValue() ? "enabled" : "disabled"));
    }
  }
}

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

// Creates a client
const client = new monitoring.AlertPolicyServiceClient();

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

  const listAlertPoliciesRequest = {
    name: client.projectPath(projectId),
    // See https://cloud.google.com/monitoring/alerting/docs/sorting-and-filtering
    filter: filter,
  };

  const [policies] = await client.listAlertPolicies(listAlertPoliciesRequest);
  const responses = [];
  for (const policy of policies) {
    responses.push(
      await client.updateAlertPolicy({
        updateMask: {
          paths: ['enabled'],
        },
        alertPolicy: {
          name: policy.name,
          enabled: {
            value: enabled,
          },
        },
      })
    );
  }
  responses.forEach(response => {
    const alertPolicy = response[0];
    console.log(`${enabled ? 'Enabled' : 'Disabled'} ${alertPolicy.name}.`);
  });
}
enablePolicies();

use Google\Cloud\Monitoring\V3\Client\AlertPolicyServiceClient;
use Google\Cloud\Monitoring\V3\ListAlertPoliciesRequest;
use Google\Cloud\Monitoring\V3\UpdateAlertPolicyRequest;
use Google\Protobuf\FieldMask;

/**
 * Enable or disable alert policies in a project.
 *
 * @param string $projectId Your project ID
 * @param bool $enable Enable or disable the policies.
 * @param string $filter Only enable/disable alert policies that match a filter.
 *        See https://cloud.google.com/monitoring/api/v3/sorting-and-filtering
 */
function alert_enable_policies($projectId, $enable = true, $filter = null)
{
    $alertClient = new AlertPolicyServiceClient([
        'projectId' => $projectId,
    ]);
    $projectName = 'projects/' . $projectId;
    $listAlertPoliciesRequest = (new ListAlertPoliciesRequest())
        ->setName($projectName)
        ->setFilter($filter);

    $policies = $alertClient->listAlertPolicies($listAlertPoliciesRequest);
    foreach ($policies->iterateAllElements() as $policy) {
        $isEnabled = $policy->getEnabled()->getValue();
        if ($enable == $isEnabled) {
            printf('Policy %s is already %s' . PHP_EOL,
                $policy->getName(),
                $isEnabled ? 'enabled' : 'disabled'
            );
        } else {
            $policy->getEnabled()->setValue((bool) $enable);
            $mask = new FieldMask();
            $mask->setPaths(['enabled']);
            $updateAlertPolicyRequest = (new UpdateAlertPolicyRequest())
                ->setAlertPolicy($policy)
                ->setUpdateMask($mask);
            $alertClient->updateAlertPolicy($updateAlertPolicyRequest);
            printf('%s %s' . PHP_EOL,
                $enable ? 'Enabled' : 'Disabled',
                $policy->getName()
            );
        }
    }
}

def enable_alert_policies(project_name, enable, filter_=None):
    """Enable or disable 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>'.
        enable (bool): Enable or disable the policies.
        filter_ (str, optional): Only enable/disable alert policies that match
            this filter_.  See
            https://cloud.google.com/monitoring/api/v3/sorting-and-filtering
    """

    client = monitoring_v3.AlertPolicyServiceClient()
    policies = client.list_alert_policies(
        request={"name": project_name, "filter": filter_}
    )

    for policy in policies:
        if bool(enable) == policy.enabled:
            print(
                "Policy",
                policy.name,
                "is already",
                "enabled" if policy.enabled else "disabled",
            )
        else:
            policy.enabled = bool(enable)
            mask = field_mask.FieldMask()
            mask.paths.append("enabled")
            client.update_alert_policy(alert_policy=policy, update_mask=mask)
            print("Enabled" if enable else "Disabled", policy.name)

static void ReplaceChannels(string projectId, string alertPolicyId,
    IEnumerable<string> channelIds)
{
    var alertClient = AlertPolicyServiceClient.Create();
    var policy = new AlertPolicy()
    {
        Name = new AlertPolicyName(projectId, alertPolicyId).ToString()
    };
    foreach (string channelId in channelIds)
    {
        policy.NotificationChannels.Add(
            new NotificationChannelName(projectId, channelId)
            .ToString());
    }
    var response = alertClient.UpdateAlertPolicy(
        new FieldMask { Paths = { "notification_channels" } }, policy);
    Console.WriteLine("Updated {0}.", response.Name);
}

// replaceChannels replaces the notification channels in the alert policy
// with channelIDs.
func replaceChannels(w io.Writer, projectID, alertPolicyID string, channelIDs []string) error {
	ctx := context.Background()

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

	policy := &monitoringpb.AlertPolicy{
		Name: "projects/" + projectID + "/alertPolicies/" + alertPolicyID,
	}
	for _, c := range channelIDs {
		c = "projects/" + projectID + "/notificationChannels/" + c
		policy.NotificationChannels = append(policy.NotificationChannels, c)
	}
	req := &monitoringpb.UpdateAlertPolicyRequest{
		AlertPolicy: policy,
		UpdateMask: &fieldmask.FieldMask{
			Paths: []string{"notification_channels"},
		},
	}
	if _, err := client.UpdateAlertPolicy(ctx, req); err != nil {
		return fmt.Errorf("UpdateAlertPolicy: %w", err)
	}
	fmt.Fprintf(w, "Successfully replaced channels.")
	return nil
}

private static void replaceChannels(String projectId, String alertPolicyId, String[] channelIds)
    throws IOException {
  AlertPolicy.Builder policyBuilder =
      AlertPolicy.newBuilder().setName(AlertPolicyName.of(projectId, alertPolicyId).toString());
  for (String channelId : channelIds) {
    policyBuilder.addNotificationChannels(
        NotificationChannelName.of(projectId, channelId).toString());
  }
  try (AlertPolicyServiceClient client = AlertPolicyServiceClient.create()) {
    AlertPolicy result =
        client.updateAlertPolicy(
            FieldMask.newBuilder().addPaths("notification_channels").build(),
            policyBuilder.build());
    System.out.println(String.format("Updated %s", result.getName()));
  }
}

// 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();

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\UpdateAlertPolicyRequest;
use Google\Protobuf\FieldMask;

/**
 * @param string $projectId Your project ID
 * @param string $alertPolicyId Your alert policy id ID
 * @param string[] $channelIds array of channel IDs
 */
function alert_replace_channels(string $projectId, string $alertPolicyId, array $channelIds): void
{
    $alertClient = new AlertPolicyServiceClient([
        'projectId' => $projectId,
    ]);

    $channelClient = new NotificationChannelServiceClient([
        'projectId' => $projectId,
    ]);
    $policy = new AlertPolicy();
    $policy->setName($alertClient->alertPolicyName($projectId, $alertPolicyId));

    $newChannels = [];
    foreach ($channelIds as $channelId) {
        $newChannels[] = $channelClient->notificationChannelName($projectId, $channelId);
    }
    $policy->setNotificationChannels($newChannels);
    $mask = new FieldMask();
    $mask->setPaths(['notification_channels']);
    $updateAlertPolicyRequest = (new UpdateAlertPolicyRequest())
        ->setAlertPolicy($policy)
        ->setUpdateMask($mask);
    $updatedPolicy = $alertClient->updateAlertPolicy($updateAlertPolicyRequest);
    printf('Updated %s' . PHP_EOL, $updatedPolicy->getName());
}

def replace_notification_channels(project_name, alert_policy_id, channel_ids):
    """Replace notification channel of an alert.

    Arguments:
        project_name (str): The Google Cloud Project to use. The project name
            must be in the format - 'projects/<PROJECT_NAME>'.
        alert_policy_id (str): The ID of the alert policy whose notification
            channels are to be replaced.
        channel_ids (str): ID of notification channel to be added as channel
            for the given alert policy.
    """

    _, project_id = project_name.split("/")
    alert_client = monitoring_v3.AlertPolicyServiceClient()
    channel_client = monitoring_v3.NotificationChannelServiceClient()
    policy = monitoring_v3.AlertPolicy()
    policy.name = alert_client.alert_policy_path(project_id, alert_policy_id)

    for channel_id in channel_ids:
        policy.notification_channels.append(
            channel_client.notification_channel_path(project_id, channel_id)
        )

    mask = field_mask.FieldMask()
    mask.paths.append("notification_channels")
    updated_policy = alert_client.update_alert_policy(
        alert_policy=policy, update_mask=mask
    )
    print("Updated", updated_policy.name)

        static void BackupPolicies(string projectId, string filePath)
        {
            var policyClient = AlertPolicyServiceClient.Create();
            var channelClient = NotificationChannelServiceClient.Create();
            var projectName = new ProjectName(projectId);
            File.WriteAllText(filePath, JsonConvert.SerializeObject(
                new BackupRecord()
                {
                    ProjectId = projectId,
                    Policies = policyClient.ListAlertPolicies(projectName),
                    Channels = channelClient.ListNotificationChannels(projectName)
                }, new ProtoMessageConverter()));
        }
        class BackupRecord
        {
            public string ProjectId { get; set; }
            public IEnumerable<AlertPolicy> Policies { get; set; }
            public IEnumerable<NotificationChannel> Channels { get; set; }
        }

        /// <summary>
        /// Lets Newtonsoft.Json and Protobuf's json converters play nicely
        /// together.  The default Netwtonsoft.Json Deserialize method will
        /// not correctly deserialize proto messages.
        /// </summary>
        class ProtoMessageConverter : JsonConverter
        {
            public override bool CanConvert(System.Type objectType)
            {
                return typeof(Google.Protobuf.IMessage)
                    .IsAssignableFrom(objectType);
            }

            public override object ReadJson(JsonReader reader,
                System.Type objectType, object existingValue,
                JsonSerializer serializer)
            {
                // Read an entire object from the reader.
                var converter = new ExpandoObjectConverter();
                object o = converter.ReadJson(reader, objectType, existingValue,
                    serializer);
                // Convert it back to json text.
                string text = JsonConvert.SerializeObject(o);
                // And let protobuf's parser parse the text.
                IMessage message = (IMessage)Activator
                    .CreateInstance(objectType);
                return Google.Protobuf.JsonParser.Default.Parse(text,
                    message.Descriptor);
            }

            public override void WriteJson(JsonWriter writer, object value,
                JsonSerializer serializer)
            {
                writer.WriteRawValue(Google.Protobuf.JsonFormatter.Default
                    .Format((IMessage)value));
            }
        }

// backupPolicies writes a JSON representation of the project's alert
// policies and notification channels.
func backupPolicies(w io.Writer, projectID string) error {
	b := backup{ProjectID: projectID}
	ctx := context.Background()

	alertClient, err := monitoring.NewAlertPolicyClient(ctx)
	if err != nil {
		return err
	}
	defer alertClient.Close()
	alertReq := &monitoringpb.ListAlertPoliciesRequest{
		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.
	}
	alertIt := alertClient.ListAlertPolicies(ctx, alertReq)
	for {
		resp, err := alertIt.Next()
		if err == iterator.Done {
			break
		}
		if err != nil {
			return err
		}
		b.AlertPolicies = append(b.AlertPolicies, &alertPolicy{resp})
	}

	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})
	}
	bs, err := json.MarshalIndent(b, "", "  ")
	if err != nil {
		return err
	}
	if _, err := w.Write(bs); err != nil {
		return err
	}
	return nil
}

// alertPolicy is a wrapper around the AlertPolicy proto to
// ensure JSON marshaling/unmarshaling works correctly.
type alertPolicy struct {
	*monitoringpb.AlertPolicy
}

// channel is a wrapper around the NotificationChannel proto to
// ensure JSON marshaling/unmarshaling works correctly.
type channel struct {
	*monitoringpb.NotificationChannel
}

// backup is used to backup and restore a project's policies.
type backup struct {
	ProjectID     string
	AlertPolicies []*alertPolicy
	Channels      []*channel
}

func (a *alertPolicy) MarshalJSON() ([]byte, error) {
	m := &jsonpb.Marshaler{EmitDefaults: true}
	b := new(bytes.Buffer)
	m.Marshal(b, a.AlertPolicy)
	return b.Bytes(), nil
}

func (a *alertPolicy) UnmarshalJSON(b []byte) error {
	u := &jsonpb.Unmarshaler{}
	a.AlertPolicy = new(monitoringpb.AlertPolicy)
	return u.Unmarshal(bytes.NewReader(b), a.AlertPolicy)
}

func (c *channel) MarshalJSON() ([]byte, error) {
	m := &jsonpb.Marshaler{}
	b := new(bytes.Buffer)
	m.Marshal(b, c.NotificationChannel)
	return b.Bytes(), nil
}

func (c *channel) UnmarshalJSON(b []byte) error {
	u := &jsonpb.Unmarshaler{}
	c.NotificationChannel = new(monitoringpb.NotificationChannel)
	return u.Unmarshal(bytes.NewReader(b), c.NotificationChannel)
}

private static void backupPolicies(String projectId, String filePath) throws IOException {
  List<AlertPolicy> alertPolicies = getAlertPolicies(projectId);
  List<NotificationChannel> notificationChannels = getNotificationChannels(projectId);
  writePoliciesBackupFile(projectId, filePath, alertPolicies, notificationChannels);
  System.out.println(String.format("Saved policies to %s", filePath));
}

private static List<AlertPolicy> getAlertPolicies(String projectId) throws IOException {
  List<AlertPolicy> alertPolicies = Lists.newArrayList();
  try (AlertPolicyServiceClient client = AlertPolicyServiceClient.create()) {
    ListAlertPoliciesPagedResponse response = client.listAlertPolicies(ProjectName.of(projectId));

    for (AlertPolicy policy : response.iterateAll()) {
      alertPolicies.add(policy);
    }
  }
  return alertPolicies;
}

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;
}

private static void writePoliciesBackupFile(
    String projectId,
    String filePath,
    List<AlertPolicy> alertPolicies,
    List<NotificationChannel> notificationChannels)
    throws IOException {
  JsonObject backupContents = new JsonObject();
  backupContents.add("project_id", new JsonPrimitive(projectId));
  JsonArray policiesJson = new JsonArray();
  for (AlertPolicy policy : alertPolicies) {
    policiesJson.add(gson.toJsonTree(policy));
  }
  backupContents.add("policies", policiesJson);

  JsonArray notificationsJson = new JsonArray();
  for (NotificationChannel channel : notificationChannels) {
    notificationsJson.add(gson.toJsonTree(channel));
  }
  backupContents.add("notification_channels", notificationsJson);

  FileWriter writer = new FileWriter(filePath);
  writer.write(backupContents.toString());
  writer.close();
}

const fs = require('fs');

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

// Creates a client
const client = new monitoring.AlertPolicyServiceClient();

async function backupPolicies() {
  /**
   * TODO(developer): Uncomment the following lines before running the sample.
   */
  // const projectId = 'YOUR_PROJECT_ID';

  const listAlertPoliciesRequest = {
    name: client.projectPath(projectId),
  };

  let [policies] = await client.listAlertPolicies(listAlertPoliciesRequest);

  // filter out any policies created by tests for this sample
  policies = policies.filter(policy => {
    return !policy.displayName.startsWith('gcloud-tests-');
  });

  fs.writeFileSync(
    './policies_backup.json',
    JSON.stringify(policies, null, 2),
    'utf-8'
  );

  console.log('Saved policies to ./policies_backup.json');

use Google\Cloud\Monitoring\V3\Client\AlertPolicyServiceClient;
use Google\Cloud\Monitoring\V3\Client\NotificationChannelServiceClient;
use Google\Cloud\Monitoring\V3\ListAlertPoliciesRequest;
use Google\Cloud\Monitoring\V3\ListNotificationChannelsRequest;

/**
 * Back up alert policies.
 *
 * @param string $projectId Your project ID
 */
function alert_backup_policies($projectId)
{
    $alertClient = new AlertPolicyServiceClient([
        'projectId' => $projectId,
    ]);
    $channelClient = new NotificationChannelServiceClient([
        'projectId' => $projectId,
    ]);
    $projectName = 'projects/' . $projectId;

    $record = [
        'project_name' => $projectName,
        'policies' => [],
        'channels' => [],
    ];
    $listAlertPoliciesRequest = (new ListAlertPoliciesRequest())
        ->setName($projectName);
    $policies = $alertClient->listAlertPolicies($listAlertPoliciesRequest);
    foreach ($policies->iterateAllElements() as $policy) {
        $record['policies'][] = json_decode($policy->serializeToJsonString());
    }
    $listNotificationChannelsRequest = (new ListNotificationChannelsRequest())
        ->setName($projectName);
    $channels = $channelClient->listNotificationChannels($listNotificationChannelsRequest);
    foreach ($channels->iterateAllElements() as $channel) {
        $record['channels'][] = json_decode($channel->serializeToJsonString());
    }
    file_put_contents('backup.json', json_encode($record, JSON_PRETTY_PRINT));
    print('Backed up alert policies and notification channels to backup.json.');
}

def backup(project_name, backup_filename):
    """Backup alert policies from a project to a local file.

    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) to which
            the alert policies will be written as backup.
    """

    alert_client = monitoring_v3.AlertPolicyServiceClient()
    channel_client = monitoring_v3.NotificationChannelServiceClient()
    record = {
        "project_name": project_name,
        "policies": list(alert_client.list_alert_policies(name=project_name)),
        "channels": list(channel_client.list_notification_channels(name=project_name)),
    }
    json.dump(record, open(backup_filename, "wt"), cls=ProtoEncoder, indent=2)
    print(
        "Backed up alert policies and notification channels to {}.".format(
            backup_filename
        )
    )


class ProtoEncoder(json.JSONEncoder):
    """Encode protobufs as json."""

    def default(self, obj):
        if type(obj) in (monitoring_v3.AlertPolicy, monitoring_v3.NotificationChannel):
            text = proto.Message.to_json(obj)
            return json.loads(text)
        return super(ProtoEncoder, self).default(obj)

        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)
            {
                string policyName = policy.Name;
                // These two fields cannot be set directly, so clear them.
                policy.CreationRecord = null;
                policy.MutationRecord = null;
                // Update channel names if the channel was recreated with
                // another name.
                for (int i = 0; i < policy.NotificationChannels.Count; ++i)
                {
                    if (channelNameMap.ContainsKey(policy.NotificationChannels[i]))
                    {
                        policy.NotificationChannels[i] =
                            channelNameMap[policy.NotificationChannels[i]];
                    }
                }
                try
                {
                    Console.WriteLine("Updating policy.\n{0}",
                        policy.DisplayName);
                    bool updated = false;
                    if (isSameProject)
                        try
                        {
                            policyClient.UpdateAlertPolicy(null, policy);
                            updated = true;
                        }
                        catch (Grpc.Core.RpcException e)
                        when (e.Status.StatusCode == StatusCode.NotFound)
                        { }
                    if (!updated)
                    {
                        // The policy no longer exists.  Recreate it.
                        policy.Name = null;
                        foreach (var condition in policy.Conditions)
                        {
                            condition.Name = null;
                        }
                        policyClient.CreateAlertPolicy(projectName, policy);
                    }
                    Console.WriteLine("Restored {0}.", policyName);
                }
                catch (Exception e)
                {
                    // If one failed, continue trying to update the others.
                    exceptions.Add(e);
                }
            }
            if (exceptions.Count > 0)
            {
                throw new AggregateException(exceptions);
            }
        }

        class BackupRecord
        {
            public string ProjectId { get; set; }
            public IEnumerable<AlertPolicy> Policies { get; set; }
            public IEnumerable<NotificationChannel> Channels { get; set; }
        }

        /// <summary>
        /// Lets Newtonsoft.Json and Protobuf's json converters play nicely
        /// together.  The default Netwtonsoft.Json Deserialize method will
        /// not correctly deserialize proto messages.
        /// </summary>
        class ProtoMessageConverter : JsonConverter
        {
            public override bool CanConvert(System.Type objectType)
            {
                return typeof(Google.Protobuf.IMessage)
                    .IsAssignableFrom(objectType);
            }

            public override object ReadJson(JsonReader reader,
                System.Type objectType, object existingValue,
                JsonSerializer serializer)
            {
                // Read an entire object from the reader.
                var converter = new ExpandoObjectConverter();
                object o = converter.ReadJson(reader, objectType, existingValue,
                    serializer);
                // Convert it back to json text.
                string text = JsonConvert.SerializeObject(o);
                // And let protobuf's parser parse the text.
                IMessage message = (IMessage)Activator
                    .CreateInstance(objectType);
                return Google.Protobuf.JsonParser.Default.Parse(text,
                    message.Descriptor);
            }

            public override void WriteJson(JsonWriter writer, object value,
                JsonSerializer serializer)
            {
                writer.WriteRawValue(Google.Protobuf.JsonFormatter.Default
                    .Format((IMessage)value));
            }
        }