Use UploadPart with an AWS SDK or CLI

//! Upload a part to an S3 bucket.
/*!
    \param bucket: The name of the S3 bucket where the object will be uploaded.
    \param key: The unique identifier (key) for the object within the S3 bucket.
    \param uploadID: An upload ID string.
    \param partNumber:
    \param checksumAlgorithm: Checksum algorithm, ignored when NOT_SET.
    \param calculatedHash: A data integrity hash to set, depending on the checksum algorithm,
                            ignored when it is an empty string.
    \param body: An shared_ptr IOStream of the data to be uploaded.
    \param client: The S3 client instance used to perform the upload operation.
    \return UploadPartOutcome: The outcome.
*/

Aws::S3::Model::UploadPartOutcome AwsDoc::S3::uploadPart(const Aws::String &bucket,
                                                         const Aws::String &key,
                                                         const Aws::String &uploadID,
                                                         int partNumber,
                                                         Aws::S3::Model::ChecksumAlgorithm checksumAlgorithm,
                                                         const Aws::String &calculatedHash,
                                                         const std::shared_ptr<Aws::IOStream> &body,
                                                         const Aws::S3::S3Client &client) {
    Aws::S3::Model::UploadPartRequest request;
    request.SetBucket(bucket);
    request.SetKey(key);
    request.SetUploadId(uploadID);
    request.SetPartNumber(partNumber);
    if (checksumAlgorithm != Aws::S3::Model::ChecksumAlgorithm::NOT_SET) {
        request.SetChecksumAlgorithm(checksumAlgorithm);
    }
    request.SetBody(body);

    if (!calculatedHash.empty()) {
        switch (checksumAlgorithm) {
            case Aws::S3::Model::ChecksumAlgorithm::NOT_SET:
                request.SetContentMD5(calculatedHash);
                break;
            case Aws::S3::Model::ChecksumAlgorithm::CRC32:
                request.SetChecksumCRC32(calculatedHash);
                break;
            case Aws::S3::Model::ChecksumAlgorithm::CRC32C:
                request.SetChecksumCRC32C(calculatedHash);
                break;
            case Aws::S3::Model::ChecksumAlgorithm::SHA1:
                request.SetChecksumSHA1(calculatedHash);
                break;
            case Aws::S3::Model::ChecksumAlgorithm::SHA256:
                request.SetChecksumSHA256(calculatedHash);
                break;
        }
    }

    return client.UploadPart(request);
}

The following command uploads the first part in a multipart upload initiated with the create-multipart-upload command:

aws s3api upload-part --bucket my-bucket --key 'multipart/01' --part-number 1 --body part01 --upload-id  "dfRtDYU0WWCCcH43C3WFbkRONycyCpTJJvxu2i5GYkZljF.Yxwh6XG7WfS2vC4to6HiV6Yjlx.cph0gtNBtJ8P3URCSbB7rjxI5iEwVDmgaXZOGgkk5nVTW16HOQ5l0R"

The body option takes the name or path of a local file for upload (do not use the file:// prefix). The minimum part size is 5 MB. Upload ID is returned by create-multipart-upload and can also be retrieved with list-multipart-uploads. Bucket and key are specified when you create the multipart upload.

Output:

{
    "ETag": "\"e868e0f4719e394144ef36531ee6824c\""
}

Save the ETag value of each part for later. They are required to complete the multipart upload.

    let mut upload_parts: Vec<aws_sdk_s3::types::CompletedPart> = Vec::new();

    for chunk_index in 0..chunk_count {
        let this_chunk = if chunk_count - 1 == chunk_index {
            size_of_last_chunk
        } else {
            CHUNK_SIZE
        };
        let stream = ByteStream::read_from()
            .path(path)
            .offset(chunk_index * CHUNK_SIZE)
            .length(Length::Exact(this_chunk))
            .build()
            .await
            .unwrap();

        // Chunk index needs to start at 0, but part numbers start at 1.
        let part_number = (chunk_index as i32) + 1;
        let upload_part_res = client
            .upload_part()
            .key(&key)
            .bucket(&bucket_name)
            .upload_id(upload_id)
            .body(stream)
            .part_number(part_number)
            .send()
            .await?;

        upload_parts.push(
            CompletedPart::builder()
                .e_tag(upload_part_res.e_tag.unwrap_or_default())
                .part_number(part_number)
                .build(),
        );
    }

    // Create a multipart upload. Use UploadPart and CompleteMultipartUpload to
    // upload the file.
    let multipart_upload_res: CreateMultipartUploadOutput = client
        .create_multipart_upload()
        .bucket(&bucket_name)
        .key(&key)
        .send()
        .await?;

    let upload_id = multipart_upload_res.upload_id().ok_or(S3ExampleError::new(
        "Missing upload_id after CreateMultipartUpload",
    ))?;

    // upload_parts: Vec<aws_sdk_s3::types::CompletedPart>
    let completed_multipart_upload: CompletedMultipartUpload = CompletedMultipartUpload::builder()
        .set_parts(Some(upload_parts))
        .build();

    let _complete_multipart_upload_res = client
        .complete_multipart_upload()
        .bucket(&bucket_name)
        .key(&key)
        .multipart_upload(completed_multipart_upload)
        .upload_id(upload_id)
        .send()
        .await?;