update: S3 driver docs (#4194)

docs/content/storage-drivers/s3.md

@@ -23,8 +23,14 @@ Amazon S3 or S3 compatible services for object storage.
 | `skipverify`  | no  | Skips TLS verification when the value is set to `true`. The default is `false`. |
 | `v4auth`  | no | Indicates whether the registry uses Version 4 of AWS's authentication. The default is `true`. |
 | `chunksize`  | no | The S3 API requires multipart upload chunks to be at least 5MB. This value should be a number that is larger than 5 * 1024 * 1024.|
+| `multipartcopychunksize` | no | Default chunk size for all but the last S3 Multipart Upload part when copying stored objects. |
+| `multipartcopymaxconcurrency` | no | Max number of concurrent S3 Multipart Upload operations when copying stored objects. |
+| `multipartcopythresholdsize` | no | Default object size above which S3 Multipart Upload will be used when copying stored objects. |
 | `rootdirectory`  | no | This is a prefix that is applied to all S3 keys to allow you to segment data in your bucket if necessary. |
 | `storageclass`  | no | The S3 storage class applied to each registry file. The default is `STANDARD`. |
+| `useragent` | no | The `User-Agent` header value for S3 API operations. |
+| `usedualstack` | no | Use AWS dual-stack API endpoints. |
+| `accelerate` | no | Enable S3 Transfer Acceleration. |
 | `objectacl`  | no | The S3 Canned ACL for objects. The default value is "private". |
 | `loglevel`  | no | The log level for the S3 client. The default value is `off`. |
 
@@ -51,10 +57,22 @@ Amazon S3 or S3 compatible services for object storage.
 
 `chunksize`: (optional) The default part size for multipart uploads (performed by WriteStream) to S3. The default is 10 MB. Keep in mind that the minimum part size for S3 is 5MB. Depending on the speed of your connection to S3, a larger chunk size may result in better performance; faster connections benefit from larger chunk sizes.
 
+`multipartcopychunksize`: (optional) The default chunk size for all but the last Upload Part in the S3 Multipart Upload operation when copying stored objects. Default value is set to `32 MB`.
+
+`multipartcopymaxconcurrency`: (optional) The default maximum number of concurrent Upload Part operations in the S3 Multipart Upload when copying stored objects. Default value is set to `100`.
+
+`multipartcopythresholdsize`: (optional) The default S3 object size above which multipart copy will be used when copying the object. Otherwise the object is copied with a single S3 API operation. Default value is set to ` 32 MB`.
+
 `rootdirectory`: (optional) The root directory tree in which all registry files are stored. Defaults to the empty string (bucket root).
 
 `storageclass`: (optional) The storage class applied to each registry file. Defaults to STANDARD. Valid options are STANDARD and REDUCED_REDUNDANCY.
 
+`useragent`: (optional) The `User-Agent` header value for S3 API operations.
+
+`usedualstack`: (optional) Use AWS dual-stack API endpoints which support requests to S3 buckets over IPv6 and IPv4.
+
+`accelerate`: (optional) Enable S3 transfer acceleration for faster transfers of files over long distances.
+
 `objectacl`: (optional) The canned object ACL to be applied to each registry object. Defaults to `private`. If you are using a bucket owned by another AWS account, it is recommended that you set this to `bucket-owner-full-control` so that the bucket owner can access your objects. Other valid options are available in the [AWS S3 documentation](https://docs.aws.amazon.com/AmazonS3/latest/dev/acl-overview.html#canned-acl).
 
 `loglevel`: (optional) Valid values are: `off` (default), `debug`, `debugwithsigning`, `debugwithhttpbody`, `debugwithrequestretries`, `debugwithrequesterrors` and `debugwitheventstreambody`. See the [AWS SDK for Go API reference](https://docs.aws.amazon.com/sdk-for-go/api/aws/#LogLevelType) for details.