@tus/server: support Tus-Max-Size

[fenos]

Based on the Tusd implementation, this PR implements a configurable maxSize option which will limit and validate incoming file size.

• We validate that the upload-length is not higher than the maxSize option provided.
• We limit the request body accordingly as in the Tusd implementation https://github.com/tus/tusd/blob/1a43e26f16f43bed5dd2219c27e6eb14c125fb03/pkg/handler/unrouted_handler.go#L810-L834

The only addition I've made is that in tusd it doesn't seem are limiting the request body to the maxSize specified.
They simply validate the upload-length header against the maxSize.

However, in this PR if the body reaches the maxSize bytes read, it will throw a 413 error and stop uploading.
Not sure about the consequences as in what happens to the part of the file that has been already uploaded?

In S3 we can set a policy to delete uncompleted multi-part but what about for fileStore?

[Murderlon]

Thanks a lot!

There is still some docs missing on this new option.

[Acconut]

Thanks to @fenos, we discovered a flaw in tusd's logic around handling size limits, so I would be a bit hesitant to copying its logic for now until we fixed that bug: tus/tusd#1032

Has this code been tested extensively with requests that use Transfer-Encoding: chunked? In these cases, no Content-Length is set and the server must keep track of the read bytes and stop if necessary on its own.

[fenos]

@Acconut I've implemented the bug fix on this PR, however will test more in depth the Transfer-Encoding: chunked in theory it should work with the current implementation

[Murderlon]

Some small comments + docs are missing, then we're good to go.

[fenos]

@Acconut @Murderlon I've made the following changes:

• I've rebased this PR
• added a test when using Transfer-Encoding: chuncked
• Validate early when Content-Lenght + offest > maxFileSize
• Added documentation
• clean up code
• no default maxFileSize set

Ready for a final review 🎉

[Acconut]

Nice work, @fenos!

[fenos]

@Murderlon S3 tests are now failing with:

InvalidAccessKeyId: The AWS Access Key Id you provided does not exist in our records.

did you revoke the access key id?

[Murderlon]

Looking great ✨ Thanks for the elaborate tests for this feature.

Only one small Q.