Autentícate en servicios de Cloud con bibliotecas cliente

En esta página, se describe cómo puedes usar las bibliotecas cliente y las credenciales predeterminadas de la aplicación para acceder a las APIs de Google.

Las bibliotecas cliente facilitan el acceso a las APIs de Google Cloud mediante un lenguaje compatible. Puedes usar las APIs de Google Cloud directamente mediante solicitudes sin procesar al servidor, pero las bibliotecas cliente proporcionan simplificaciones que reducen de manera significativa la cantidad de código que debes escribir. Esto se aplica en particular a la autenticación, ya que las bibliotecas cliente son compatibles con las credenciales predeterminadas de la aplicación (ADC).

Si deseas usar una clave de API, no debes usar ADC. Para obtener más información, consulta Usa una clave de API con bibliotecas cliente.

Usa las credenciales predeterminadas de la aplicación con bibliotecas cliente

Si quieres usar las credenciales predeterminadas de la aplicación para autenticar tu aplicación, primero debes configurar ADC para el entorno en el que se ejecuta tu aplicación. Cuando usas la biblioteca cliente para crear un cliente, esta busca y usa de forma automática las credenciales que proporcionaste a ADC para autenticarte en las APIs que usa tu código. Tu aplicación no necesita autenticar ni administrar tokens de forma explícita. Las bibliotecas de autenticación administran estos requisitos de forma automática.

Para un entorno de desarrollo local, puedes configurar ADC con las credenciales de usuario mediante la CLI de gcloud. Para los entornos de producción, debes configurar las ADC mediante la conexión de una cuenta de servicio.

Ejemplo de creación de cliente

Las siguientes muestras de código crean un cliente para el servicio de Cloud Storage. Es probable que tu código necesite diferentes clientes. El propósito de estos ejemplos es solo mostrar cómo puedes crear un cliente y usarlo sin ningún código para autenticarte de forma explícita.

Antes de ejecutar las siguientes muestras, debes configurar ADC para tu entorno y, luego, instalar la biblioteca cliente de Cloud Storage.

Comienza a usarlo

auth/authenticate_implicit_with_adc.go 
import (
	"context"
	"fmt"
	"io"

	"cloud.google.com/go/storage"
	"google.golang.org/api/iterator"
)

// authenticateImplicitWithAdc uses Application Default Credentials
// to automatically find credentials and authenticate.
func authenticateImplicitWithAdc(w io.Writer, projectId string) error {
	// projectId := "your_project_id"

	ctx := context.Background()

	// NOTE: Replace the client created below with the client required for your application.
	// Note that the credentials are not specified when constructing the client.
	// The client library finds your credentials using ADC.
	client, err := storage.NewClient(ctx)
	if err != nil {
		return fmt.Errorf("NewClient: %w", err)
	}
	defer client.Close()

	it := client.Buckets(ctx, projectId)
	for {
		bucketAttrs, err := it.Next()
		if err == iterator.Done {
			break
		}
		if err != nil {
			return err
		}
		fmt.Fprintf(w, "Bucket: %v\n", bucketAttrs.Name)
	}

	fmt.Fprintf(w, "Listed all storage buckets.\n")

	return nil
}

Java

samples/snippets/src/main/java/AuthenticateImplicitWithAdc.java 

import com.google.api.gax.paging.Page;
import com.google.cloud.storage.Bucket;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;
import java.io.IOException;

public class AuthenticateImplicitWithAdc {

  public static void main(String[] args) throws IOException {
    // TODO(Developer):
    //  1. Before running this sample,
    //  set up Application Default Credentials as described in
    //  https://cloud.google.com/docs/authentication/external/set-up-adc
    //  2. Replace the project variable below.
    //  3. Make sure you have the necessary permission to list storage buckets
    //  "storage.buckets.list"
    String projectId = "your-google-cloud-project-id";
    authenticateImplicitWithAdc(projectId);
  }

  // When interacting with Google Cloud Client libraries, the library can auto-detect the
  // credentials to use.
  public static void authenticateImplicitWithAdc(String project) throws IOException {

    // *NOTE*: Replace the client created below with the client required for your application.
    // Note that the credentials are not specified when constructing the client.
    // Hence, the client library will look for credentials using ADC.
    //
    // Initialize client that will be used to send requests. This client only needs to be created
    // once, and can be reused for multiple requests.
    Storage storage = StorageOptions.newBuilder().setProjectId(project).build().getService();

    System.out.println("Buckets:");
    Page<Bucket> buckets = storage.list();
    for (Bucket bucket : buckets.iterateAll()) {
      System.out.println(bucket.toString());
    }
    System.out.println("Listed all storage buckets.");
  }
}

Node.js

samples/authenticateImplicitWithAdc.js 
/**
 * TODO(developer):
 *  1. Uncomment and replace these variables before running the sample.
 *  2. Set up ADC as described in https://cloud.google.com/docs/authentication/external/set-up-adc
 *  3. Make sure you have the necessary permission to list storage buckets "storage.buckets.list"
 *    (https://cloud.google.com/storage/docs/access-control/iam-permissions#bucket_permissions)
 */
// const projectId = 'YOUR_PROJECT_ID';

const {Storage} = require('@google-cloud/storage');

async function authenticateImplicitWithAdc() {
  // This snippet demonstrates how to list buckets.
  // NOTE: Replace the client created below with the client required for your application.
  // Note that the credentials are not specified when constructing the client.
  // The client library finds your credentials using ADC.
  const storage = new Storage({
    projectId,
  });
  const [buckets] = await storage.getBuckets();
  console.log('Buckets:');

  for (const bucket of buckets) {
    console.log(`- ${bucket.name}`);
  }

  console.log('Listed all storage buckets.');
}

authenticateImplicitWithAdc();

Python

samples/cloud-client/snippets/authenticate_implicit_with_adc.py 

from google.cloud import storage

def authenticate_implicit_with_adc(project_id="your-google-cloud-project-id"):
    """
    When interacting with Google Cloud Client libraries, the library can auto-detect the
    credentials to use.

    // TODO(Developer):
    //  1. Before running this sample,
    //  set up ADC as described in https://cloud.google.com/docs/authentication/external/set-up-adc
    //  2. Replace the project variable.
    //  3. Make sure that the user account or service account that you are using
    //  has the required permissions. For this sample, you must have "storage.buckets.list".
    Args:
        project_id: The project id of your Google Cloud project.
    """

    # This snippet demonstrates how to list buckets.
    # *NOTE*: Replace the client created below with the client required for your application.
    # Note that the credentials are not specified when constructing the client.
    # Hence, the client library will look for credentials using ADC.
    storage_client = storage.Client(project=project_id)
    buckets = storage_client.list_buckets()
    print("Buckets:")
    for bucket in buckets:
        print(bucket.name)
    print("Listed all storage buckets.")

Ruby

samples/authenticate_implicit_with_adc.rb 
def authenticate_implicit_with_adc project_id:
  # The ID of your Google Cloud project
  # project_id = "your-google-cloud-project-id"

  ###
  # When interacting with Google Cloud Client libraries, the library can auto-detect the
  # credentials to use.
  # TODO(Developer):
  #   1. Before running this sample,
  #      set up ADC as described in https://cloud.google.com/docs/authentication/external/set-up-adc
  #   2. Replace the project variable.
  #   3. Make sure that the user account or service account that you are using
  #      has the required permissions. For this sample, you must have "storage.buckets.list".
  ###

  require "google/cloud/storage"

  # This sample demonstrates how to list buckets.
  # *NOTE*: Replace the client created below with the client required for your application.
  # Note that the credentials are not specified when constructing the client.
  # Hence, the client library will look for credentials using ADC.
  storage = Google::Cloud::Storage.new project_id: project_id
  buckets = storage.buckets
  puts "Buckets: "
  buckets.each do |bucket|
    puts bucket.name
  end
  puts "Plaintext: Listed all storage buckets."
end

¿Qué sigue?