S3 Compatibility - UploadPartCopy

[ferristocrat]

Background

What is the problem/pain point?

Many S3 libraries such as boto3 for Python set a object size threshold, after which, uploads and copies will default to multipart upload. Given that we do not currently support multipart copy (link to that endpoint) this default threshold will return an error.

What is the impact?

Customers expect their integrations to “just work” when Storj advertises S3 Compatibility. This feature gap frustrates customers as they’re onboarding and if not resolved, we will lose business.

Why now?

Customers are asking for this and it helps round out our compatibility with the “core” features of the S3 API.

Requirements

Assumptions

• Objects can only be copied between buckets within the same Storj DCS account

Out of Scope

• Will not support copying objects from one Storj account to another
  • Open question: What would be the additional lift to support this? This is supported in Amazon S3 using access points only when the source and destination buckets are in the same AWS Region

User Story

As a Storj DCS User I want to be able to use UploadPartCopy to copy large objects already within a Storj DCS bucket so that I can switch from my existing S3 compatible storage to Storj without having to change my multipart copy configuration.

S3 Method: UploadPartCopy - Uploads a part by copying data from an existing object as data source.

Acceptance Criteria

Request Params

Param	Description	Required?	Support Needed?
Bucket	The bucket name	Yes	✅
Key	Object key for which the multipart upload was initiated.	Yes	✅
partNumber	Part number of part being copied. This is a positive integer between 1 and 10,000.	Yes	✅
uploadId	Upload ID identifying the multipart upload whose part is being copied.	Yes	✅
x-amz-copy-source	Specifies the source object for the copy operation.	Yes	✅
x-amz-copy-source-if-match	Copies the object if its entity tag (ETag) matches the specified tag.	No	❌
x-amz-copy-source-if-modified-since	Copies the object if it has been modified since the specified time.	No	❌
x-amz-copy-source-if-none-match	Copies the object if its entity tag (ETag) is different than the specified ETag.	No	❌
x-amz-copy-source-if-unmodified-since	Copies the object if it hasn't been modified since the specified time.	No	❌
x-amz-copy-source-range	The range of bytes to copy from the source object. The range value must use the form bytes=first-last, where the first and last are the zero-based byte offsets to copy. For example, bytes=0-9 indicates that you want to copy the first 10 bytes of the source. You can copy a range only if the source object is greater than 5 MB.	Yes	✅
x-amz-copy-source-server-side-encryption-customer-algorithm	Specifies the algorithm to use when decrypting the source object (for example, AES256).	No	❌
x-amz-copy-source-server-side-encryption-customer-key	Specifies the customer-provided encryption key for Amazon S3 to use to decrypt the source object.	No	❌
x-amz-copy-source-server-side-encryption-customer-key-MD5	Specifies the 128-bit MD5 digest of the encryption key according to RFC 1321.	No	❌
x-amz-expected-bucket-owner	The account ID of the expected destination bucket owner.	No	❌
x-amz-request-payer	Confirms that the requester knows that they will be charged for the request.	No	❌
x-amz-server-side-encryption-customer-algorithm	Specifies the algorithm to use to when encrypting the object (for example, AES256).	No	❌
x-amz-server-side-encryption-customer-key	Specifies the customer-provided encryption key for Amazon S3 to use in encrypting data.	No	❌
x-amz-server-side-encryption-customer-key-MD5	Specifies the 128-bit MD5 digest of the encryption key according to RFC 1321.	No	❌
x-amz-source-expected-bucket-owner	The account ID of the expected source bucket owner.	No	❌

Response Elements

Element	Description	Required?	Support Needed?	Notes
CopyPartResult	Root level tag for the CopyPartResult parameters.	Yes	✅
ETag	Entity tag of the object.	Maybe	Maybe
LastModified	Date and time at which the object was uploaded.	Maybe	Maybe
x-amz-copy-source-version-id	The version of the source object that was copied, if you have enabled versioning on the source bucket.	No	❌	Do not yet support object versioning
x-amz-request-charged	If present, indicates that the requester was successfully charged for the request.	No	❌
x-amz-server-side-encryption	The server-side encryption algorithm used when storing this object in Amazon S3 (for example, AES256, aws:kms)	No	❌
x-amz-server-side-encryption-aws-kms-key-id	If present, specifies the ID of the AWS Key Management Service (AWS KMS) symmetric encryption customer managed key that was used for the object.	No	❌
x-amz-server-side-encryption-bucket-key-enabled	Indicates whether the multipart upload uses an S3 Bucket Key for server-side encryption with AWS KMS (SSE-KMS).	No	❌
x-amz-server-side-encryption-customer-algorithm	If server-side encryption with a customer-provided encryption key was requested, the response will include this header confirming the encryption algorithm used.	No	❌
x-amz-server-side-encryption-customer-key-MD5	If server-side encryption with a customer-provided encryption key was requested, the response will include this header to provide round-trip message integrity verification of the customer-provided encryption key.	No	❌
ChecksumCRC32	The base64-encoded, 32-bit CRC32 checksum of the object. This will only be present if it was uploaded with the object. With multipart uploads, this may not be a checksum value of the object.	No	❌
ChecksumCRC32C	The base64-encoded, 32-bit CRC32C checksum of the object. This will only be present if it was uploaded with the object. With multipart uploads, this may not be a checksum value of the object.	No	❌
ChecksumSHA1	The base64-encoded, 160-bit SHA-1 digest of the object. This will only be present if it was uploaded with the object. With multipart uploads, this may not be a checksum value of the object.	No	❌
ChecksumSHA256	The base64-encoded, 256-bit SHA-256 digest of the object. This will only be present if it was uploaded with the object. With multipart uploads, this may not be a checksum value of the object.	No	❌

Measures of Success

• TBD

Useful Links

• Blueprint
• Blueprint Review

[shaupt131]

Week 25 update

Completed:

• Engineering/Product meeting to discuss possible solutions

In Progress:

• Draft system design

[ferristocrat]

Estimation ticket: storj/storj#4875