Content-type on Zarr JSON files in S3

[jeffdlb]

The LENS Zarr JSON metadata files such as .zarray have ContentType=binary/octet-stream instead of application/json. Can we (a) set ContentType correctly for future uploads and (b) fix this for existing objects on S3?

Example:

2264> aws s3api head-object --bucket ncar-cesm-lens --key atm/monthly/cesmLE-20C-FLNS.zarr/FLNS/.zarray
{
    "AcceptRanges": "bytes", 
    "ContentType": "binary/octet-stream", 
    "LastModified": "Fri, 19 Jul 2019 15:13:27 GMT", 
    "ContentLength": 393, 
    "VersionId": "GUtdv6h2i2wKbJdMuzMfzjsXxfDsuJSZ", 
    "ETag": "\"6bb1f5299a15258d4fa193679be5daed\"", 
    "Metadata": {}
}

Ryan Abernathy pointed out (in the Zarr development github) that "Content type is determined by the uploader: https://docs.aws.amazon.com/AmazonS3/latest/API/API_PutObject.html
When writing or copying zarr to s3, you could specify a Content-Type: application/json header for those files."