Get Bucket Policy

You can use these codes to get your bucket policy.

Components

• Credentials
• Bucket Name

.NET

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

using Amazon;
using Amazon.S3;
using Amazon.S3.Model;
using System;
using System.Diagnostics;
using System.Threading.Tasks;
using System.Reflection;

namespace GetBucketPolicy
{
  class GetBucketPolicy
  {
      // This example shows how to check a bucket existence.
      //  The examples uses AWS SDK for .NET 3.5 and .NET 5.0.

      private static IAmazonS3 _s3Client;

      // Specify the name of the bucket to check.
      private const string BUCKET_NAME = "<BUCKET_NAME>";

      static async Task Main()
      {
          var awsCredentials = new Amazon.Runtime.BasicAWSCredentials("<ACCESS-KEY>", "<SECRET-KEY>");
          var config = new AmazonS3Config { ServiceURL = "<ENDPOINT>" };
          _s3Client = new AmazonS3Client(awsCredentials, config);

          await GetBucketPolicyAsync(_s3Client, BUCKET_NAME);
      }

      /// <summary>
      /// GetBucketPolicyAsync calls the DoesS3BucketExistV2Async method
      /// to get bucket's policies.
      /// </summary>
      /// <param name="client">The Amazon S3 client object.</param>
      /// <param name="bucketName">The name of the bucket to check.</param>
      static async Task GetBucketPolicyAsync(IAmazonS3 client, string bucketName)
      {
          GetBucketPolicyRequest getRequest = new GetBucketPolicyRequest
          {
              BucketName = bucketName
          };
          Object policy = await client.GetBucketPolicyAsync(getRequest);

          foreach (PropertyInfo prop in policy.GetType().GetProperties())
          {
              Console.WriteLine($"{prop.Name}: {prop.GetValue(policy, null)}");
          }
      }
  }
}

PHP

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

// Get the policy of a specific bucket
try {
  $resp = $client->getBucketPolicy([
      'Bucket' => $bucket
  ]);
  echo "Succeed in receiving bucket policy:\n";
  echo (string) $resp->get('Policy');
} catch (AwsException $e) {
  // Display error message
  echo $e->getMessage();
}

Python

import boto3
import logging
from botocore.exceptions import ClientError

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

try:
   s3_resource = boto3.resource(
       '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 = 'sample_bucket'
       bucket_policy = s3_resource.BucketPolicy(bucket_name)
       bucket_policy.load()
       logging.info(bucket_policy.policy)
   except ClientError as e:
       logging.error(e)

Javascript

// Import required AWS SDK clients and commands for Node.js
const { S3Client, GetBucketPolicyCommand } = 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',
  },
});

// call S3 to retrieve upload file to specified bucket
const run = async () => {
  try {
      const response = await s3.send(
          new GetBucketPolicyCommand({
              Bucket: 'sample_bucket',
          })
      );
      console.log('Success', response.Policy);
  } catch (err) {
      console.log('Error', err.Code);
  }
};

run();

GO

package main

import (
  "bytes"
  "encoding/json"
  "fmt"
  "os"
  "path/filepath"

  "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"
)

// Prints the policy for a bucket. If the bucket doesn't exist, or there was
// and error an error message will be printed instead.
//
// Usage:
//    go run s3_get_bucket_policy.go BUCKET_NAME
func main() {
  if len(os.Args) != 2 {
      exitErrorf("bucket name required\nUsage: %s bucket_name",
          filepath.Base(os.Args[0]))
  }

  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>"),
  })

  // Call S3 to retrieve the policy for the selected bucket.
  result, err := svc.GetBucketPolicy(&s3.GetBucketPolicyInput{
      Bucket: aws.String(bucket),
  })
  if err != nil {
      // Special error handling for the when the bucket doesn't
      // exists so we can give a more direct error message from the CLI.
      if aerr, ok := err.(awserr.Error); ok {
          switch aerr.Code() {
          case s3.ErrCodeNoSuchBucket:
              exitErrorf("Bucket %q does not exist.", bucket)
          case "NoSuchBucketPolicy":
              exitErrorf("Bucket %q does not have a policy.", bucket)
          }
      }
      exitErrorf("Unable to get bucket %q policy, %v.", bucket, err)
  }

  out := bytes.Buffer{}
  policyStr := aws.StringValue(result.Policy)
  if err := json.Indent(&out, []byte(policyStr), "", "  "); err != nil {
      exitErrorf("Failed to pretty print bucket policy, %v.", err)
  }

  fmt.Printf("%q's Bucket Policy:\n", bucket)
  fmt.Println(out.String())
}

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_policy.go:

go run s3_get_bucket_policy.go BUCKET_NAME