无法在S3上创建分段上传

Question

I am very new to amazon web services and I am trying to create a file and upload it to S3 using the below code :

let uploadCsvToS3 = (fileData, csvName) => {
    let data = fileData;
    let readObj = new Readable();
    let timeOfErrorLog = timeUtility.convertDateToUnixTS(new Date());
    let errorLogFileName = `errorlog/errorlog_${timeOfErrorLog}_${csvName}`;
    readObj.push(data); // Push the CSV
    readObj.push(null); // Signal that we're done writing the CSV
    var upload = s3Stream.upload({
        "Bucket": "bucketname",
        "Key": errorLogFileName
    });
    readObj.pipe(upload);
    upload.on('error', function (error) {
        console.log('error is:',error);
        console.log(`There was an error uploading error file: ${errorLogFileName} on S3`);
    });
    upload.on('uploaded', function (details) {
        console.log(`Successfully Uploaded error log file on S3 by name: ${errorLogFileName}`);
        console.log(details);
        markErrorLogAsDumped(csvName);
    });
}

It works fine when I run it on local but when I try to execute the same via AWS lambda, it throws this error :

Failed to create a multipart upload on S3:
{
    "message": "Access Denied",
    "code": "AccessDenied",
    "region": null,
    "time": "2019-01-14T10:21:01.983Z",
    "requestId": "24FC75B2103C1FC4",
    "extendedRequestId": "iTDnNrMWSfixL9j6S6yDz68AgTIZthUlTzjZ/Rwrqu7CUJj5f4lrq2Ds7hFapbvzko3DYyRGA/E=",
    "statusCode": 403,
    "retryable": false,
    "retryDelay": 64.85863274563219
}

What could be the problem?

Answer 1

It may work on your local test because it will be using your AWS Credentials. You need to ensure that the role assumed by your Lambda has write permissions to target S3 location.

For example:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "Stmt1547468052811",
      "Action": "s3:*",
      "Effect": "Allow",
      "Resource": "arn:aws:s3:::<bucket_name>/"
    }
  ]
}