it's extremely painful to find A Working Solution to needing to update the Cache-Control on all your S3 objects while retaining all the other metadata fields.

This is the only solution I can find -- using s3cmd. The regular s3cli doesn't work, nor do libraries for various languages I've tried.


s3cmd --recursive modify --add-header="Cache-Control:public, max-age=608400" --acl-private s3://your-bucket/