Get Object Metadata

Get object metadata without downloading it

Components

• Credentials
• Bucket Name
• Object 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.Threading.Tasks;
using System.Reflection;
using Newtonsoft.Json;

namespace HeadObject
{
  class HeadObject
  {
      private static IAmazonS3 _s3Client;

      private const string BUCKET_NAME = "<BUCKET_NAME>";
      private const string OBJECT_NAME = "<OBJECT_NAME>";

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

          HeadObjectHelper().Wait();
      }

      private static async Task HeadObjectHelper()
      {
          try
          {
              // Create the request
              GetObjectMetadataRequest request = new ()
              {
                  BucketName = BUCKET_NAME,
                  Key = OBJECT_NAME
              };

              // Submit the request
              GetObjectMetadataResponse response = await _s3Client.GetObjectMetadataAsync(request);

              Console.WriteLine(JsonConvert.SerializeObject(response, Formatting.Indented));
          }
          catch (AmazonS3Exception amazonS3Exception)
          {
              Console.WriteLine("An AmazonS3Exception was thrown. Exception: " + amazonS3Exception.ToString());
          }
          catch (Exception e)
          {
              Console.WriteLine("Exception: " + e.ToString());
          }
      }
  }
}

Python

import boto3
import logging
from botocore.exceptions import ClientError


logging.basicConfig(level=logging.INFO)

try:
   s3_client = 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:
       response = s3_client.head_object(Bucket="smaple-bucket", Key="sample-object")
   except ClientError as err:
       status = err.response["ResponseMetadata"]["HTTPStatusCode"]
       errcode = err.response["Error"]["Code"]

       if status == 404:
           logging.warning("Missing object, %s", errcode)
       elif status == 403:
           logging.error("Access denied, %s", errcode)
       else:
           logging.exception("Error in request, %s", errcode)
   else:
       logging.info(response)

Javascript

// Import required AWS SDK clients and commands for Node.js
const { S3Client, HeadObjectCommand } = 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 HeadObjectCommand({
              Bucket: 'sample_bucket',
              Key: 'file.png',
              VersionId: 'versionId',
          })
      );
      console.log('Success', response);
  } catch (err) {
      console.log('Error', err);
  }
};

run();

GO

package main

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"
)

// Deletes the specified object in the specified S3 Bucket in the region configured in the shared config
// or AWS_REGION environment variable.
//
// Usage:
//    go run s3_head_object BUCKET_NAME OBJECT_NAME
func main() {
  if len(os.Args) != 3 {
      exitErrorf("Bucket and object name required\nUsage: %s bucket_name object_name",
          os.Args[0])
  }

  bucket := os.Args[1]
  obj := os.Args[2]

  // Initialize a session in us-west-2 that the SDK will use to load
  // credentials from the shared credentials file ~/.aws/credentials.
  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.HeadObjectInput{
      Bucket: aws.String(bucket),
      Key:    aws.String(obj),
  }

  result, err := svc.HeadObject(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)
}

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_head_object.go:

go run s3_head_object BUCKET_NAME OBJECT_NAME