rclone/cmd/serve/s3/serve_s3.md

serve s3 implements a basic s3 server that serves a remote via s3. This can be viewed with an s3 client, or you can make an s3 type remote to read and write to it with rclone.

serve s3 is considered Experimental so use with care.

S3 server supports Signature Version 4 authentication. Just use --auth-key accessKey,secretKey and set the Authorization header correctly in the request. (See the AWS docs).

--auth-key can be repeated for multiple auth pairs. If --auth-key is not provided then serve s3 will allow anonymous access.

Please note that some clients may require HTTPS endpoints. See the SSL docs for more information.

This command uses the VFS directory cache. All the functionality will work with --vfs-cache-mode off. Using --vfs-cache-mode full (or writes) can be used to cache objects locally to improve performance.

Use --force-path-style=false if you want to use the bucket name as a part of the hostname (such as mybucket.local)

Use --etag-hash if you want to change the hash uses for the ETag. Note that using anything other than MD5 (the default) is likely to cause problems for S3 clients which rely on the Etag being the MD5.

Quickstart

For a simple set up, to serve remote:path over s3, run the server like this:

rclone serve s3 --auth-key ACCESS_KEY_ID,SECRET_ACCESS_KEY remote:path

For example, to use a simple folder in the filesystem, run the server with a command like this:

rclone serve s3 --auth-key ACCESS_KEY_ID,SECRET_ACCESS_KEY local:/path/to/folder

The rclone.conf for the server could look like this:

[local]
type = local

The local configuration is optional though. If you run the server with a remote:path like /path/to/folder (without the local: prefix and without an rclone.conf file), rclone will fall back to a default configuration, which will be visible as a warning in the logs. But it will run nonetheless.

This will be compatible with an rclone (client) remote configuration which is defined like this:

[serves3]
type = s3
provider = Rclone
endpoint = http://127.0.0.1:8080/
access_key_id = ACCESS_KEY_ID
secret_access_key = SECRET_ACCESS_KEY
use_multipart_uploads = false

Note that setting disable_multipart_uploads = true is to work around a bug which will be fixed in due course.

Bugs

When uploading multipart files serve s3 holds all the parts in memory (see #7453). This is a limitaton of the library rclone uses for serving S3 and will hopefully be fixed at some point.

Multipart server side copies do not work (see #7454). These take a very long time and eventually fail. The default threshold for multipart server side copies is 5G which is the maximum it can be, so files above this side will fail to be server side copied.

For a current list of serve s3 bugs see the serve s3 bug category on GitHub.

Limitations

serve s3 will treat all directories in the root as buckets and ignore all files in the root. You can use CreateBucket to create folders under the root, but you can't create empty folders under other folders not in the root.

When using PutObject or DeleteObject, rclone will automatically create or clean up empty folders. If you don't want to clean up empty folders automatically, use --no-cleanup.

When using ListObjects, rclone will use / when the delimiter is empty. This reduces backend requests with no effect on most operations, but if the delimiter is something other than / and empty, rclone will do a full recursive search of the backend, which can take some time.

Versioning is not currently supported.

Metadata will only be saved in memory other than the rclone mtime metadata which will be set as the modification time of the file.

Supported operations

serve s3 currently supports the following operations.

• Bucket
  • ListBuckets
  • CreateBucket
  • DeleteBucket
• Object
  • HeadObject
  • ListObjects
  • GetObject
  • PutObject
  • DeleteObject
  • DeleteObjects
  • CreateMultipartUpload
  • CompleteMultipartUpload
  • AbortMultipartUpload
  • CopyObject
  • UploadPart

Other operations will return error Unimplemented.