List devices

Retrieves the identifiers of devices for a specific registry.

Explore further

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

Code sample

Go

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

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


// listDevices gets the identifiers of devices for a specific registry.
func listDevices(w io.Writer, projectID string, region string, registryID string) ([]*cloudiot.Device, error) {
	// Authorize the client using Application Default Credentials.
	// See https://g.co/dv/identity/protocols/application-default-credentials
	ctx := context.Background()
	httpClient, err := google.DefaultClient(ctx, cloudiot.CloudPlatformScope)
	if err != nil {
		return nil, err
	}
	client, err := cloudiot.New(httpClient)
	if err != nil {
		return nil, err
	}

	parent := fmt.Sprintf("projects/%s/locations/%s/registries/%s", projectID, region, registryID)
	response, err := client.Projects.Locations.Registries.Devices.List(parent).Do()
	if err != nil {
		return nil, err
	}

	fmt.Fprintln(w, "Devices:")
	for _, device := range response.Devices {
		fmt.Fprintf(w, "\t%s\n", device.Id)
	}

	return response.Devices, nil
}

Java

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

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

/** Print all of the devices in this registry to standard out. */
protected static void listDevices(String projectId, String cloudRegion, String registryName)
    throws GeneralSecurityException, IOException {
  GoogleCredentials credential =
      GoogleCredentials.getApplicationDefault().createScoped(CloudIotScopes.all());
  JsonFactory jsonFactory = GsonFactory.getDefaultInstance();
  HttpRequestInitializer init = new HttpCredentialsAdapter(credential);
  final CloudIot service =
      new CloudIot.Builder(GoogleNetHttpTransport.newTrustedTransport(), jsonFactory, init)
          .setApplicationName(APP_NAME)
          .build();

  final String registryPath =
      String.format(
          "projects/%s/locations/%s/registries/%s", projectId, cloudRegion, registryName);

  List<Device> devices =
      service
          .projects()
          .locations()
          .registries()
          .devices()
          .list(registryPath)
          .execute()
          .getDevices();

  if (devices != null) {
    System.out.println("Found " + devices.size() + " devices");
    for (Device d : devices) {
      System.out.println("Id: " + d.getId());
      if (d.getConfig() != null) {
        // Note that this will show the device config in Base64 encoded format.
        System.out.println("Config: " + d.getConfig().toPrettyString());
      }
      System.out.println();
    }
  } else {
    System.out.println("Registry has no devices.");
  }
}

PHP

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

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

use Google\Cloud\Iot\V1\DeviceManagerClient;

/**
 * List all devices in the registry.
 *
 * @param string $registryId IOT Device Registry ID
 * @param string $projectId Google Cloud project ID
 * @param string $location (Optional) Google Cloud region
 */
function list_devices(
    $registryId,
    $projectId,
    $location = 'us-central1'
) {
    print('Listing devices' . PHP_EOL);

    // Instantiate a client.
    $deviceManager = new DeviceManagerClient();

    // Format the full registry path
    $registryName = $deviceManager->registryName($projectId, $location, $registryId);

    // Call the API
    $devices = $deviceManager->listDevices($registryName);

    // Print the result
    foreach ($devices->iterateAllElements() as $device) {
        printf('Device: %s : %s' . PHP_EOL,
            $device->getNumId(),
            $device->getId());
    }
}

Python

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

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

# project_id = 'YOUR_PROJECT_ID'
# cloud_region = 'us-central1'
# registry_id = 'your-registry-id'
print("Listing devices")

client = iot_v1.DeviceManagerClient()
registry_path = client.registry_path(project_id, cloud_region, registry_id)

# See full list of device fields: https://cloud.google.com/iot/docs/reference/cloudiot/rest/v1/projects.locations.registries.devices
# Warning! Use snake_case field names.
field_mask = gp_field_mask.FieldMask(
    paths=[
        "id",
        "name",
        "num_id",
        "credentials",
        "last_heartbeat_time",
        "last_event_time",
        "last_state_time",
        "last_config_ack_time",
        "last_config_send_time",
        "blocked",
        "last_error_time",
        "last_error_status",
        "config",
        "state",
        "log_level",
        "metadata",
        "gateway_config",
    ]
)

devices = list(
    client.list_devices(request={"parent": registry_path, "field_mask": field_mask})
)
for device in devices:
    print(device)

return devices

Ruby

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

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

# project_id  = "Your Google Cloud project ID"
# location_id = "The Cloud region the registry is located in"
# registry_id = "The registry to list devices from"

require "google/apis/cloudiot_v1"

# Initialize the client and authenticate with the specified scope
Cloudiot   = Google::Apis::CloudiotV1
iot_client = Cloudiot::CloudIotService.new
iot_client.authorization = Google::Auth.get_application_default(
  "https://www.googleapis.com/auth/cloud-platform"
)

# The resource name of the location associated with the project
resource = "projects/#{project_id}/locations/#{location_id}/registries/#{registry_id}"

# List the devices in the provided region
response = iot_client.list_project_location_registry_devices(
  resource
)

puts "Devices:"
if response.devices && response.devices.any?
  response.devices.each { |device| puts "\t#{device.id}" }
else
  puts "\tNo device registries found in this region for your project."
end

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