s3.PutObject: A header you provided implies functionality that is not implemented

[pwaller]

        resp, err := s3client.PutObject(&s3.PutObjectRequest{
            Bucket: aws.String("mybucket"),
            Key:    aws.String("foo/bar"),
            Body:   r.Body,
        })

I'm getting an err of A header you provided implies functionality that is not implemented. I can't figure out what I might be doing wrong, is there some missing information?

[pwaller]

I think what actually happened is that ContentLength is compulsory. Is this bug then that aws-sdk-go doesn't check that the header is provided?

Is there a way of doing an upload when the size isn't known in advance?

[lsegal]

@pwaller ContentLength will be calculated automatically by the SDK when it can (there is code for this in develop), but note that it is a required field and cannot be omitted by the SDK (whether it's automatically filled or not).

One trick you can use to get around this restriction is to use multipart uploads, which allows you to send an object as multiple arbitrary sized parts (though you must know the size of each individual part). You can see the multipart upload overview documentation for more information on this technique.

Note that a multipart upload has to be at minimum 5mb, so you would have to buffer that much into memory and determine if you can use this technique before actually initiating the request.