List buckets using Amazon S3 SDKs

List Cloud Storage buckets that use Amazon Simple Storage Service (Amazon S3) SDKs by using the Cloud Storage XML API with HMAC credentials.

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

Code sample

Go

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

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries. 

import (
	"context"
	"fmt"
	"io"
	"time"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/credentials"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/s3"
)

func listGCSBuckets(w io.Writer, googleAccessKeyID string, googleAccessKeySecret string) error {
	// googleAccessKeyID := "Your Google Access Key ID"
	// googleAccessKeySecret := "Your Google Access Key Secret"

	// Create a new client and do the following:
	// 1. Change the endpoint URL to use the Google Cloud Storage XML API endpoint.
	// 2. Use Cloud Storage HMAC Credentials.
	sess := session.Must(session.NewSession(&aws.Config{
		Region:      aws.String("auto"),
		Endpoint:    aws.String("https://storage.googleapis.com"),
		Credentials: credentials.NewStaticCredentials(googleAccessKeyID, googleAccessKeySecret, ""),
	}))

	client := s3.New(sess)
	ctx := context.Background()

	ctx, cancel := context.WithTimeout(ctx, time.Second*10)
	defer cancel()
	result, err := client.ListBucketsWithContext(ctx, &s3.ListBucketsInput{})
	if err != nil {
		return fmt.Errorf("ListBucketsWithContext: %w", err)
	}

	fmt.Fprintf(w, "Buckets:")
	for _, b := range result.Buckets {
		fmt.Fprintf(w, "%s\n", aws.StringValue(b.Name))
	}

	return nil
}

Java

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

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries. 

import com.amazonaws.auth.AWSStaticCredentialsProvider;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.client.builder.AwsClientBuilder;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3ClientBuilder;
import com.amazonaws.services.s3.model.Bucket;
import java.util.List;

public class ListGcsBuckets {
  public static void listGcsBuckets(String googleAccessKeyId, String googleAccessKeySecret) {

    // String googleAccessKeyId = "your-google-access-key-id";
    // String googleAccessKeySecret = "your-google-access-key-secret";

    // Create a BasicAWSCredentials using Cloud Storage HMAC credentials.
    BasicAWSCredentials googleCreds =
        new BasicAWSCredentials(googleAccessKeyId, googleAccessKeySecret);

    // Create a new client and do the following:
    // 1. Change the endpoint URL to use the Google Cloud Storage XML API endpoint.
    // 2. Use Cloud Storage HMAC Credentials.
    AmazonS3 interopClient =
        AmazonS3ClientBuilder.standard()
            .withEndpointConfiguration(
                new AwsClientBuilder.EndpointConfiguration(
                    "https://storage.googleapis.com", "auto"))
            .withCredentials(new AWSStaticCredentialsProvider(googleCreds))
            .build();

    // Call GCS to list current buckets
    List<Bucket> buckets = interopClient.listBuckets();

    // Print bucket names
    System.out.println("Buckets:");
    for (Bucket bucket : buckets) {
      System.out.println(bucket.getName());
    }

    // Explicitly clean up client resources.
    interopClient.shutdown();
  }

Python

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

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries. 

import boto3  # type: ignore


def list_gcs_buckets(
    google_access_key_id: str, google_access_key_secret: str
) -> List[str]:
    """Lists all Cloud Storage buckets using AWS SDK for Python (boto3)
    Positional arguments:
        google_access_key_id: hash-based message authentication code (HMAC) access ID
        google_access_key_secret: HMAC access secret

    Returned value is a list of strings, one for each bucket name.

    To use this sample:
    1. Create a Cloud Storage HMAC key: https://cloud.google.com/storage/docs/authentication/managing-hmackeys#create
    2. Change endpoint_url to a Google Cloud Storage XML API endpoint.

    To learn more about HMAC: https://cloud.google.com/storage/docs/authentication/hmackeys#overview
    """
    client = boto3.client(
        "s3",
        region_name="auto",
        endpoint_url="https://storage.googleapis.com",
        aws_access_key_id=google_access_key_id,
        aws_secret_access_key=google_access_key_secret,
    )

    # Call GCS to list current buckets
    response = client.list_buckets()

    # Return list of bucket names
    results = []
    for bucket in response["Buckets"]:
        results.append(bucket["Name"])
        print(bucket["Name"])  # Can remove if not needed after development
    return results

What's next

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