Get Bucket CORS Settings

Using this set of codes, you can get your bucket CORS settings.

Components

• Credentials
• Bucket Name

.NET

// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX - License - Identifier: Apache - 2.0

namespace GetBucketCors
{
  using System;
  using System.Collections.Generic;
  using System.Threading.Tasks;
  using Amazon;
  using Amazon.S3;
  using Amazon.S3.Model;

  /// <summary>
  /// This example show how to get cors configurations. This example was
  /// created using the AWS SDK for .NET 3.7 and .NET Core 5.0.
  /// </summary>
  public class GetBucketCors
  {
      // Remember to change the bucket name to the name of an Amazon Simple
      // Storage Service (Amazon S3) bucket that exists on your account.
      private const string BucketName = "<BUCKET_NAME>";

      /// <summary>
      /// The Main method creates the the bucket to be able to accept CORS
      /// requests.
      /// </summary>
      public static async Task Main()
      {
          var awsCredentials = new Amazon.Runtime.BasicAWSCredentials("<ACCESS-KEY>", "<SECRET-KEY>");
          var config = new AmazonS3Config { ServiceURL = "<ENDPOINT>" };
          var _s3Client = new AmazonS3Client(awsCredentials, config);
          await RetrieveCORSConfigurationAsync(_s3Client);
      }

      /// <summary>
      ///
      /// </summary>
      /// <param name="client"></param>
      /// <returns></returns>
      private static async Task<CORSConfiguration> RetrieveCORSConfigurationAsync(AmazonS3Client client)
      {
          GetCORSConfigurationRequest request = new ()
          {
              BucketName = BucketName,
          };
          var response = await client.GetCORSConfigurationAsync(request);
          var configuration = response.Configuration;
          PrintCORSRules(configuration);
          return configuration;
      }

      /// <summary>
      ///
      /// </summary>
      /// <param name="configuration"></param>
      private static void PrintCORSRules(CORSConfiguration configuration)
      {
          Console.WriteLine();

          if (configuration is null)
          {
              Console.WriteLine("\nConfiguration is null");
              return;
          }

          Console.WriteLine($"Configuration has {configuration.Rules.Count} rules:");
          foreach (CORSRule rule in configuration.Rules)
          {
              Console.WriteLine($"Rule ID: {rule.Id}");
              Console.WriteLine($"MaxAgeSeconds: {rule.MaxAgeSeconds}");
              Console.WriteLine($"AllowedMethod: {string.Join(", ", rule.AllowedMethods.ToArray())}");
              Console.WriteLine($"AllowedOrigins: {string.Join(", ", rule.AllowedOrigins.ToArray())}");
              Console.WriteLine($"AllowedHeaders: {string.Join(", ", rule.AllowedHeaders.ToArray())}");
              Console.WriteLine($"ExposeHeader: {string.Join(", ", rule.ExposeHeaders.ToArray())}");
          }
      }
  }
}

PHP

<?php
require('client.php');
$bucket = $config['sample_bucket'];

try {
  $result = $client->getBucketCors([
      'Bucket' => $bucket, // REQUIRED
  ]);
  var_dump($result);
} catch (AwsException $e) {
  // Display error message
  echo $e->getMessage();
  echo "\n";
}

Python

import boto3
import logging
from botocore.exceptions import ClientError

# Configure logging
logging.basicConfig(level=logging.INFO)

try:
   # S3 resource
   s3_resource = boto3.client(
       's3',
       endpoint_url='endpoint_url',
       aws_access_key_id='access_key',
       aws_secret_access_key='secret_key'
   )

except Exception as exc:
   logging.error(exc)
else:
   try:
       bucket_name = 'bucket_name'
       response = s3_client.get_bucket_cors(Bucket=bucket_name)
       logging.info(response['CORSRules'])
   except ClientError as e:
       if e.response['Error']['Code'] == 'NoSuchCORSConfiguration':
           return []
       else:
           # AllAccessDisabled error == bucket not found
           logging.error(e)

Javascript

// Import required AWS SDK clients and commands for Node.js
const { S3Client, GetBucketCorsCommand } = require('@aws-sdk/client-s3');

// Create an S3 client service object
const s3 = new S3Client({
  region: 'default',
  endpoint: 'endpoint_url',
  credentials: {
      accessKeyId: 'access_key',
      secretAccessKey: 'secret_key',
  },
});

const run = async () => {
  try {
      const response = await s3.send(
          new GetBucketCorsCommand({
              Bucket: 'sample_bucket',
          })
      );
      console.log('Success', response.CORSRules);
  } catch (err) {
      console.log('Error', err);
  }
};
run();

GO

package main

// snippet-start:[s3.go.set_cors.imports]
import (
  "fmt"
  "os"

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

// Lists CORS configuration
//
// Usage:
//    go run s3_get_bucket_cors.go BUCKET_NAME
func main() {

  if len(os.Args) != 2 {
      exitErrorf("Bucket name required\nUsage: go run", os.Args[0], "BUCKET")
  }

  bucket := os.Args[1]

  sess, err := session.NewSession(&aws.Config{
      Credentials: credentials.NewStaticCredentials("<ACCESS_KEY>", "<SECRET_KEY>", ""),
  })
  svc := s3.New(sess, &aws.Config{
      Region:   aws.String("default"),
      Endpoint: aws.String("<ENDPOINT_URL>"),
  })
  input := &s3.GetBucketCorsInput{
      Bucket: aws.String(bucket),
  }

  result, err := svc.GetBucketCors(input)
  if err != nil {
      if aerr, ok := err.(awserr.Error); ok {
          switch aerr.Code() {
          default:
              fmt.Println(aerr.Error())
          }
      } else {
          // Print the error, cast err to awserr.Error to get the Code and
          // Message from an error.
          fmt.Println(err.Error())
      }
      return
  }

  fmt.Println(result)
}

// snippet-start:[s3.go.set_cors.exit]
func exitErrorf(msg string, args ...interface{}) {
  fmt.Fprintf(os.Stderr, msg+"\n", args...)
  os.Exit(1)
}

The following command can be used to execute the aforementioned code, presuming the code file is called s3_get_bucket_cors.go:

go run s3_get_bucket_cors.go BUCKET