ObjectSummary / Action / initiate_multipart_upload

initiate_multipart_upload#

S3.ObjectSummary.initiate_multipart_upload(**kwargs)#

This action initiates a multipart upload and returns an upload ID. This upload ID is used to associate all of the parts in the specific multipart upload. You specify this upload ID in each of your subsequent upload part requests (see UploadPart). You also include this upload ID in the final request to either complete or abort the multipart upload request.

For more information about multipart uploads, see Multipart Upload Overview.

If you have configured a lifecycle rule to abort incomplete multipart uploads, the upload must complete within the number of days specified in the bucket lifecycle configuration. Otherwise, the incomplete multipart upload becomes eligible for an abort action and Amazon S3 aborts the multipart upload. For more information, see Aborting Incomplete Multipart Uploads Using a Bucket Lifecycle Policy.

For information about the permissions required to use the multipart upload API, see Multipart Upload and Permissions.

For request signing, multipart upload is just a series of regular requests. You initiate a multipart upload, send one or more requests to upload parts, and then complete the multipart upload process. You sign each request individually. There is nothing special about signing multipart upload requests. For more information about signing, see Authenticating Requests (Amazon Web Services Signature Version 4).

Note

After you initiate a multipart upload and upload one or more parts, to stop being charged for storing the uploaded parts, you must either complete or abort the multipart upload. Amazon S3 frees up the space used to store the parts and stop charging you for storing them only after you either complete or abort a multipart upload.

You can optionally request server-side encryption. For server-side encryption, Amazon S3 encrypts your data as it writes it to disks in its data centers and decrypts it when you access it. You can provide your own encryption key, or use Amazon Web Services KMS keys or Amazon S3-managed encryption keys. If you choose to provide your own encryption key, the request headers you provide in UploadPart and UploadPartCopy requests must match the headers you used in the request to initiate the upload by using CreateMultipartUpload.

To perform a multipart upload with encryption using an Amazon Web Services KMS key, the requester must have permission to the kms:Decrypt and kms:GenerateDataKey* actions on the key. These permissions are required because Amazon S3 must decrypt and read data from the encrypted file parts before it completes the multipart upload. For more information, see Multipart upload API and permissions in the Amazon S3 User Guide.

If your Identity and Access Management (IAM) user or role is in the same Amazon Web Services account as the KMS key, then you must have these permissions on the key policy. If your IAM user or role belongs to a different account than the key, then you must have the permissions on both the key policy and your IAM user or role.

For more information, see Protecting Data Using Server-Side Encryption.

Access Permissions

When copying an object, you can optionally specify the accounts or groups that should be granted specific permissions on the new object. There are two ways to grant the permissions using the request headers:

  • Specify a canned ACL with the x-amz-acl request header. For more information, see Canned ACL.

  • Specify access permissions explicitly with the x-amz-grant-read, x-amz-grant-read-acp, x-amz-grant-write-acp, and x-amz-grant-full-control headers. These parameters map to the set of permissions that Amazon S3 supports in an ACL. For more information, see Access Control List (ACL) Overview.

You can use either a canned ACL or specify access permissions explicitly. You cannot do both.

Server-Side- Encryption-Specific Request Headers

You can optionally tell Amazon S3 to encrypt data at rest using server-side encryption. Server-side encryption is for data encryption at rest. Amazon S3 encrypts your data as it writes it to disks in its data centers and decrypts it when you access it. The option you use depends on whether you want to use Amazon Web Services managed encryption keys or provide your own encryption key.

  • Use encryption keys managed by Amazon S3 or customer managed key stored in Amazon Web Services Key Management Service (Amazon Web Services KMS) – If you want Amazon Web Services to manage the keys used to encrypt data, specify the following headers in the request.

    • x-amz-server-side-encryption

    • x-amz-server-side-encryption-aws-kms-key-id

    • x-amz-server-side-encryption-context

Note

If you specify x-amz-server-side-encryption:aws:kms, but don’t provide x-amz-server-side-encryption-aws-kms-key-id, Amazon S3 uses the Amazon Web Services managed key in Amazon Web Services KMS to protect the data.

Warning

All GET and PUT requests for an object protected by Amazon Web Services KMS fail if you don’t make them with SSL or by using SigV4.

For more information about server-side encryption with KMS key (SSE-KMS), see Protecting Data Using Server-Side Encryption with KMS keys.

  • Use customer-provided encryption keys – If you want to manage your own encryption keys, provide all the following headers in the request.

    • x-amz-server-side-encryption-customer-algorithm

    • x-amz-server-side-encryption-customer-key

    • x-amz-server-side-encryption-customer-key-MD5

For more information about server-side encryption with KMS keys (SSE-KMS), see Protecting Data Using Server-Side Encryption with KMS keys.

Access-Control-List (ACL)-Specific Request Headers

You also can use the following access control–related headers with this operation. By default, all objects are private. Only the owner has full access control. When adding a new object, you can grant permissions to individual Amazon Web Services accounts or to predefined groups defined by Amazon S3. These permissions are then added to the access control list (ACL) on the object. For more information, see Using ACLs. With this operation, you can grant access permissions using one of the following two methods:

  • Specify a canned ACL ( x-amz-acl) — Amazon S3 supports a set of predefined ACLs, known as canned ACLs. Each canned ACL has a predefined set of grantees and permissions. For more information, see Canned ACL.

  • Specify access permissions explicitly — To explicitly grant access permissions to specific Amazon Web Services accounts or groups, use the following headers. Each header maps to specific permissions that Amazon S3 supports in an ACL. For more information, see Access Control List (ACL) Overview. In the header, you specify a list of grantees who get the specific permission. To grant permissions explicitly, use:

    • x-amz-grant-read

    • x-amz-grant-write

    • x-amz-grant-read-acp

    • x-amz-grant-write-acp

    • x-amz-grant-full-control

You specify each grantee as a type=value pair, where the type is one of the following:

  • id – if the value specified is the canonical user ID of an Amazon Web Services account

  • uri – if you are granting permissions to a predefined group

  • emailAddress – if the value specified is the email address of an Amazon Web Services account

Note

Using email addresses to specify a grantee is only supported in the following Amazon Web Services Regions:

  • US East (N. Virginia)

  • US West (N. California)

  • US West (Oregon)

  • Asia Pacific (Singapore)

  • Asia Pacific (Sydney)

  • Asia Pacific (Tokyo)

  • Europe (Ireland)

  • South America (São Paulo)

For a list of all the Amazon S3 supported Regions and endpoints, see Regions and Endpoints in the Amazon Web Services General Reference.

For example, the following x-amz-grant-read header grants the Amazon Web Services accounts identified by account IDs permissions to read object data and its metadata:

x-amz-grant-read: id="11112222333", id="444455556666"

The following operations are related to CreateMultipartUpload:

See also: AWS API Documentation

Request Syntax

multipart_upload = object_summary.initiate_multipart_upload(
    ACL='private'|'public-read'|'public-read-write'|'authenticated-read'|'aws-exec-read'|'bucket-owner-read'|'bucket-owner-full-control',
    CacheControl='string',
    ContentDisposition='string',
    ContentEncoding='string',
    ContentLanguage='string',
    ContentType='string',
    Expires=datetime(2015, 1, 1),
    GrantFullControl='string',
    GrantRead='string',
    GrantReadACP='string',
    GrantWriteACP='string',
    Metadata={
        'string': 'string'
    },
    ServerSideEncryption='AES256',
    StorageClass='ACCELERATED'|'STANDARD'|'REDUCED_REDUNDANCY'|'STANDARD_IA'|'ONEZONE_IA'|'INTELLIGENT_TIERING'|'GLACIER'|'DEEP_ARCHIVE'|'OUTPOSTS'|'GLACIER_IR',
    WebsiteRedirectLocation='string',
    SSECustomerAlgorithm='string',
    SSECustomerKey='string',
    SSEKMSKeyId='string',
    RequestPayer='requester',
    Tagging='string',
    ObjectLockMode='GOVERNANCE'|'COMPLIANCE',
    ObjectLockRetainUntilDate=datetime(2015, 1, 1),
    ObjectLockLegalHoldStatus='ON'|'OFF',
    ExpectedBucketOwner='string'
)
Parameters:

  • ACL (string) –

    The canned ACL to apply to the object.

    This action is not supported by Amazon S3 on Outposts.

  • CacheControl (string) – Specifies caching behavior along the request/reply chain.

  • ContentDisposition (string) – Specifies presentational information for the object.

  • ContentEncoding (string) – Specifies what content encodings have been applied to the object and thus what decoding mechanisms must be applied to obtain the media-type referenced by the Content-Type header field.

  • ContentLanguage (string) – The language that the content is in.

  • ContentType (string) – A standard MIME type describing the format of the object data.

  • Expires (datetime) – The date and time at which the object is no longer cacheable.

  • GrantFullControl (string) –

    Gives the grantee READ, READ_ACP, and WRITE_ACP permissions on the object.

    This action is not supported by Amazon S3 on Outposts.

  • GrantRead (string) –

    Allows grantee to read the object data and its metadata.

    This action is not supported by Amazon S3 on Outposts.

  • GrantReadACP (string) –

    Allows grantee to read the object ACL.

    This action is not supported by Amazon S3 on Outposts.

  • GrantWriteACP (string) –

    Allows grantee to write the ACL for the applicable object.

    This action is not supported by Amazon S3 on Outposts.

  • Metadata (dict) –

    A map of metadata to store with the object in S3.

    • (string) –

      • (string) –

  • ServerSideEncryption (string) –

    The server-side encryption algorithm used when you store this object in Amazon S3 (for example, AES256, aws:kms).

    Note

    For directory buckets, only server-side encryption with Amazon S3 managed keys (SSE-S3) ( AES256) is supported.

  • StorageClass (string) – By default, Amazon S3 uses the STANDARD Storage Class to store newly created objects. The STANDARD storage class provides high durability and high availability. Depending on performance needs, you can specify a different Storage Class. Amazon S3 on Outposts only uses the OUTPOSTS Storage Class. For more information, see Storage Classes in the Amazon S3 User Guide.

  • WebsiteRedirectLocation (string) – If the bucket is configured as a website, redirects requests for this object to another object in the same bucket or to an external URL. Amazon S3 stores the value of this header in the object metadata.

  • SSECustomerAlgorithm (string) – Specifies the algorithm to use to when encrypting the object (for example, AES256).

  • SSECustomerKey (string) – Specifies the customer-provided encryption key for Amazon S3 to use in encrypting data. This value is used to store the object and then it is discarded; Amazon S3 does not store the encryption key. The key must be appropriate for use with the algorithm specified in the x-amz-server-side-encryption-customer-algorithm header.

  • SSECustomerKeyMD5 (string) –

    Specifies the 128-bit MD5 digest of the encryption key according to RFC 1321. Amazon S3 uses this header for a message integrity check to ensure that the encryption key was transmitted without error.

    Please note that this parameter is automatically populated if it is not provided. Including this parameter is not required

  • SSEKMSKeyId (string) – Specifies the ID of the symmetric customer managed key to use for object encryption. All GET and PUT requests for an object protected by Amazon Web Services KMS will fail if not made via SSL or using SigV4. For information about configuring using any of the officially supported Amazon Web Services SDKs and Amazon Web Services CLI, see Specifying the Signature Version in Request Authentication in the Amazon S3 User Guide.

  • RequestPayer (string) – Ignored by COS if present.

  • Tagging (string) – The tag-set for the object. The tag-set must be encoded as URL Query parameters.

  • ObjectLockMode (string) – Specifies the Object Lock mode that you want to apply to the uploaded object.

  • ObjectLockRetainUntilDate (datetime) – The date and time when you want the copied object’s Object Lock to expire.

  • ObjectLockLegalHoldStatus (string) – Specifies whether you want to apply a legal hold to the uploaded object.

  • ExpectedBucketOwner (string) – Ignored by COS if present.

Return type:

s3.MultipartUpload

Returns:

MultipartUpload resource