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Filename : s3.rst
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List objects in an Amazon S3 bucket
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

The following example shows how to use an Amazon S3 bucket resource to list
the objects in the bucket.

.. code-block:: python

    import boto3

    s3 = boto3.resource('s3')
    bucket = s3.Bucket('my-bucket')
    for obj in bucket.objects.all():
        print(obj.key)


List top-level common prefixes in Amazon S3 bucket
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

This example shows how to list all of the top-level common prefixes in an
Amazon S3 bucket:

.. code-block:: python

    import boto3

    client = boto3.client('s3')
    paginator = client.get_paginator('list_objects')
    result = paginator.paginate(Bucket='my-bucket', Delimiter='/')
    for prefix in result.search('CommonPrefixes'):
        print(prefix.get('Prefix'))


Restore Glacier objects in an Amazon S3 bucket
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

The following example shows how to initiate restoration of glacier objects in
an Amazon S3 bucket, determine if a restoration is on-going, and determine if a
restoration is finished.

.. code-block:: python

    import boto3

    s3 = boto3.resource('s3')
    bucket = s3.Bucket('glacier-bucket')
    for obj_sum in bucket.objects.all():
        obj = s3.Object(obj_sum.bucket_name, obj_sum.key)
        if obj.storage_class == 'GLACIER':
            # Try to restore the object if the storage class is glacier and
            # the object does not have a completed or ongoing restoration
            # request.
            if obj.restore is None:
                print('Submitting restoration request: %s' % obj.key)
                obj.restore_object(RestoreRequest={'Days': 1})
            # Print out objects whose restoration is on-going
            elif 'ongoing-request="true"' in obj.restore:
                print('Restoration in-progress: %s' % obj.key)
            # Print out objects whose restoration is complete
            elif 'ongoing-request="false"' in obj.restore:
                print('Restoration complete: %s' % obj.key)


Uploading/downloading files using SSE KMS
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

This example shows how to use SSE-KMS to upload objects using
server side encryption with a key managed by KMS.

We can either use the default KMS master key, or create a
custom key in AWS and use it to encrypt the object by passing in its
key id.

With KMS, nothing else needs to be provided for getting the
object; S3 already knows how to decrypt the object.


.. code-block:: python

    import boto3
    import os

    BUCKET = 'your-bucket-name'
    s3 = boto3.client('s3')
    keyid = '<the key id>'

    print("Uploading S3 object with SSE-KMS")
    s3.put_object(Bucket=BUCKET,
                  Key='encrypt-key',
                  Body=b'foobar',
                  ServerSideEncryption='aws:kms',
                  # Optional: SSEKMSKeyId
                  SSEKMSKeyId=keyid)
    print("Done")

    # Getting the object:
    print("Getting S3 object...")
    response = s3.get_object(Bucket=BUCKET,
                             Key='encrypt-key')
    print("Done, response body:")
    print(response['Body'].read())


Uploading/downloading files using SSE Customer Keys
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

This example shows how to use SSE-C to upload objects using
server side encryption with a customer provided key.

First, we'll need a 32 byte key.  For this example, we'll
randomly generate a key but you can use any 32 byte key
you want.  Remember, you must the same key to download
the object.  If you lose the encryption key, you lose
the object.

Also note how we don't have to provide the SSECustomerKeyMD5.
Boto3 will automatically compute this value for us.


.. code-block:: python

    import boto3
    import os

    BUCKET = 'your-bucket-name'
    KEY = os.urandom(32)
    s3 = boto3.client('s3')

    print("Uploading S3 object with SSE-C")
    s3.put_object(Bucket=BUCKET,
                  Key='encrypt-key',
                  Body=b'foobar',
                  SSECustomerKey=KEY,
                  SSECustomerAlgorithm='AES256')
    print("Done")

    # Getting the object:
    print("Getting S3 object...")
    # Note how we're using the same ``KEY`` we
    # created earlier.
    response = s3.get_object(Bucket=BUCKET,
                             Key='encrypt-key',
                             SSECustomerKey=KEY,
                             SSECustomerAlgorithm='AES256')
    print("Done, response body:")
    print(response['Body'].read())