Uploading a file to S3 without reading it

This post covers uploading a file to S3. It's pretty simple: make an HTTP/1.1 PUT request and now your file is in the cloud 🪄. What could possibly be interesting about something so mundane? Well, we're going to leverage the Linux kernel to do it in an unnecessarily efficient way. (Note: I think FreeBSD also supports this but I haven't tried it.) We'll be looking at a novel way - used by no…