How can I ensure the task of downloading a specific folder from an S3 Bucket?

In the context of AWS, you can tackle the task of downloading a specific folder from an S3 bucket to a local machine by using the AWS SDK for Python programming language along with some Python libraries for handling the purpose of interruptions and verifying the Integrity of the download files.

Setting up AWS Credentials

You should try to ensure that your AWS credentials should be Configured. You can set them up by using the AWS CLU or just by setting environment variables.

Installing necessary libraries

You should install the boto3 to interact with the S3 and any other necessary libraries such as Boto3, botocare for the verification.

Download folder

You can also implement logic to download the folder recursively.

Checking verification

After completing the process of downloading each file, you should try to compute its checksums and then compare it with the S3 object checksum to verify Integrity.

Here is the approach given:-

Import os

Import boto3

Import botocore

Import hashlib

# Initialize the S3 client

S3_client = boto3.client(‘s3’)

# Configuration variables

Bucket_name = ‘your-bucket-name’

Folder_path = ‘path/to/your/folder’

Local_path = ‘path/to/local/directory’

Def list_files_in_s3_folder(bucket, folder):

    “””

    List all files in the specified S3 folder.

    “””

    S3_objects = []

    Paginator = s3_client.get_paginator(‘list_objects_v2’)

    For page in paginator.paginate(Bucket=bucket, Prefix=folder):

        S3_objects.extend(page.get(‘Contents’, []))

    Return s3_objects

Def download_file(s3_object):

    “””

    Download a single file from S3 and verify its checksum.

    “””

    S3_key = s3_object[‘Key’]

    Local_file_path = os.path.join(local_path, os.path.relpath(s3_key, folder_path))

    Os.makedirs(os.path.dirname(local_file_path), exist_ok=True)

    Try:

        S3_client.download_file(bucket_name, s3_key, local_file_path)

        Print(f”Downloaded: {s3_key}”)

    Except botocore.exceptions.ClientError as e:

        Print(f”Failed to download {s3_key}: {e}”)

        Return False

    If not verify_checksum(s3_key, local_file_path):

        Print(f”Checksum mismatch for {s3_key}”)

        Return False

    Return True

Def verify_checksum(s3_key, local_file_path):

    “””

    Verify the checksum of the downloaded file against the S3 object’s ETag.

    “””

    S3_object = s3_client.head_object(Bucket=bucket_name, Key=s3_key)

    S3_etag = s3_object[‘ETag’].strip(‘”’)

    Md5_hash = hashlib.md5()

    With open(local_file_path, ‘rb’) as f:

        For chunk in iter(lambda: f.read(4096), b’’):

            Md5_hash.update(chunk)

    Local_md5 = md5_hash.hexdigest()

    Return s3_etag == local_md5

Def download_folder(bucket, folder):

    “””

    Download all files in the specified S3 folder.

    “””

    S3_objects = list_files_in_s3_folder(bucket, folder)

    For s3_object in s3_objects:

        If not download_file(s3_object):

            Print(f”Retrying download: {s3_object[‘Key’]}”)

            Download_file(s3_object)

If __name__ == “__main__”:

    Download_folder(bucket_name, folder_path)