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Use GetBucketCors with an AWS SDK or CLI

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The following code examples show how to use GetBucketCors.

.NET

AWS SDK for .NET

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

        /// <summary>
        /// Retrieve the CORS configuration applied to the Amazon S3 bucket.
        /// </summary>
        /// <param name="client">The initialized Amazon S3 client object used
        /// to retrieve the CORS configuration.</param>
        /// <returns>The created CORS configuration object.</returns>
        private static async Task<CORSConfiguration> RetrieveCORSConfigurationAsync(AmazonS3Client client)
        {
            GetCORSConfigurationRequest request = new GetCORSConfigurationRequest()
            {
                BucketName = BucketName,
            };
            var response = await client.GetCORSConfigurationAsync(request);
            var configuration = response.Configuration;
            PrintCORSRules(configuration);
            return configuration;
        }

• For API details, see GetBucketCors in AWS SDK for .NET API Reference.

CLI

AWS CLI

The following command retrieves the Cross-Origin Resource Sharing configuration for a bucket named amzn-s3-demo-bucket:

aws s3api get-bucket-cors --bucket amzn-s3-demo-bucket

Output:

{
    "CORSRules": [
        {
            "AllowedHeaders": [
                "*"
            ],
            "ExposeHeaders": [
                "x-amz-server-side-encryption"
            ],
            "AllowedMethods": [
                "PUT",
                "POST",
                "DELETE"
            ],
            "MaxAgeSeconds": 3000,
            "AllowedOrigins": [
                "http://www.example.com"
            ]
        },
        {
            "AllowedHeaders": [
                "Authorization"
            ],
            "MaxAgeSeconds": 3000,
            "AllowedMethods": [
                "GET"
            ],
            "AllowedOrigins": [
                "*"
            ]
        }
    ]
}

• For API details, see GetBucketCors in AWS CLI Command Reference.

JavaScript

SDK for JavaScript (v3)

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

Get the CORS policy for the bucket.

import {
  GetBucketCorsCommand,
  S3Client,
  S3ServiceException,
} from "@aws-sdk/client-s3";

/**
 * Log the Cross-Origin Resource Sharing (CORS) configuration information
 * set for the bucket.
 * @param {{ bucketName: string }}
 */
export const main = async ({ bucketName }) => {
  const client = new S3Client({});
  const command = new GetBucketCorsCommand({
    Bucket: bucketName,
  });

  try {
    const { CORSRules } = await client.send(command);
    console.log(JSON.stringify(CORSRules));
    CORSRules.forEach((cr, i) => {
      console.log(
        `\nCORSRule ${i + 1}`,
        `\n${"-".repeat(10)}`,
        `\nAllowedHeaders: ${cr.AllowedHeaders}`,
        `\nAllowedMethods: ${cr.AllowedMethods}`,
        `\nAllowedOrigins: ${cr.AllowedOrigins}`,
        `\nExposeHeaders: ${cr.ExposeHeaders}`,
        `\nMaxAgeSeconds: ${cr.MaxAgeSeconds}`,
      );
    });
  } catch (caught) {
    if (
      caught instanceof S3ServiceException &&
      caught.name === "NoSuchBucket"
    ) {
      console.error(
        `Error from S3 while getting bucket CORS rules for ${bucketName}. The bucket doesn't exist.`,
      );
    } else if (caught instanceof S3ServiceException) {
      console.error(
        `Error from S3 while getting bucket CORS rules for ${bucketName}.  ${caught.name}: ${caught.message}`,
      );
    } else {
      throw caught;
    }
  }
};

• For more information, see AWS SDK for JavaScript Developer Guide.

• For API details, see GetBucketCors in AWS SDK for JavaScript API Reference.

Python

SDK for Python (Boto3)

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

class BucketWrapper:
    """Encapsulates S3 bucket actions."""

    def __init__(self, bucket):
        """
        :param bucket: A Boto3 Bucket resource. This is a high-level resource in Boto3
                       that wraps bucket actions in a class-like structure.
        """
        self.bucket = bucket
        self.name = bucket.name


    def get_cors(self):
        """
        Get the CORS rules for the bucket.

        :return The CORS rules for the specified bucket.
        """
        try:
            cors = self.bucket.Cors()
            logger.info(
                "Got CORS rules %s for bucket '%s'.", cors.cors_rules, self.bucket.name
            )
        except ClientError:
            logger.exception(("Couldn't get CORS for bucket %s.", self.bucket.name))
            raise
        else:
            return cors

• For API details, see GetBucketCors in AWS SDK for Python (Boto3) API Reference.

Ruby

SDK for Ruby

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

require 'aws-sdk-s3'

# Wraps Amazon S3 bucket CORS configuration.
class BucketCorsWrapper
  attr_reader :bucket_cors

  # @param bucket_cors [Aws::S3::BucketCors] A bucket CORS object configured with an existing bucket.
  def initialize(bucket_cors)
    @bucket_cors = bucket_cors
  end

  # Gets the CORS configuration of a bucket.
  #
  # @return [Aws::S3::Type::GetBucketCorsOutput, nil] The current CORS configuration for the bucket.
  def cors
    @bucket_cors.data
  rescue Aws::Errors::ServiceError => e
    puts "Couldn't get CORS configuration for #{@bucket_cors.bucket.name}. Here's why: #{e.message}"
    nil
  end

end

• For API details, see GetBucketCors in AWS SDK for Ruby API Reference.

For a complete list of AWS SDK developer guides and code examples, see Developing with Amazon S3 using the AWS SDKs. This topic also includes information about getting started and details about previous SDK versions.