How to download a file using from s3 private bucket without AWS cli

Question

Is it possible to download a file from AWS s3 without AWS cli? In my production server I would need to download a config file which is in S3 bucket.

I was thinking of having Amazon Systems Manger run a script that would download the config (YAML files) from the S3. But we do not want to install AWS cli on the production machines. How can I go about this?

Feel free to edit your question to add more information (eg which operating system, what limitations you are under) if the answers don't provide enough details. — John Rotenstein, Jul 11 '20 at 02:57

score 3 · Accepted Answer · answered Jul 11 '20 at 02:56

3

You would need some sort of program to call the Amazon S3 API to retrieve the object. For example, a PowerShell script (using AWS Tools for Windows PowerShell) or a Python script that uses the AWS SDK.

You could alternatively generate an Amazon S3 pre-signed URL, which would allow a private object to be downloaded from Amazon S3 via a normal HTTPS call (eg curl). This can be done easily using the AWS SDK for Python, or you could code it yourself without using libraries (it's a bit more complex).

In all examples above, you would need to provide the script/program with a set of IAM Credentials for authenticating with AWS.

answered Jul 11 '20 at 02:56

John Rotenstein

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"or you could code it yourself without using libraries (it's a bit more complex)." Do you happen to have a reference for how to do it? I'm having trouble finding one. – Mike B Jun 08 '23 at 22:30
1

@MikeB [Sample Python code to generate presigned URL - AWS IoT Core](https://docs.aws.amazon.com/iot/latest/developerguide/connect-iot-lorawan-network-analyzer-request-sample.html) – John Rotenstein Jun 08 '23 at 22:38

score 0 · Answer 2 · answered Jan 03 '21 at 21:38

Just adding notes for any C# code lovers to solve problem with .Net

Firstly write(C#) code to download private file as string

 public string DownloadPrivateFileS3(string fileKey)
 {
     string accessKey = "YOURVALUE";
     string accessSecret = "YOURVALUE";;
     string bucket = "YOURVALUE";;
     using (s3Client = new AmazonS3Client(accessKey, accessSecret, "YOURVALUE"))
     {
             var folderPath = "AppData/Websites/Cases";
             var fileTransferUtility = new TransferUtility(s3Client);
             Stream stream = fileTransferUtility.OpenStream(bucket, folderPath + "/" + fileKey);
             using (var memoryStream = new MemoryStream())
             {
                  stream.CopyTo(memoryStream);
                 var response = memoryStream.ToArray();
                 return Convert.ToBase64String(response);
             }

             return "";
    }
}

Second Write JQuery Code to download string as Base64

function downloadPrivateFile() {
$.ajax({url: 'DownloadPrivateFileS3?fileName=' + fileName, success: function(result){
        var link = this.document.createElement('a');
        link.download = fileName;
        link.href = "data:application/octet-stream;base64," + result;
        this.document.body.appendChild(link);
        link.click();
        this.document.body.removeChild(link);
  }});
}

Call downloadPrivateFile method from anywhere of HTML/C#/JQuery -

Enjoy Happy Coding and Solutions of Complex Problems

How to download a file using from s3 private bucket without AWS cli

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