Glance-new-upload-workflow

This is the full specification for blueprint:https://blueprints.launchpad.net/glance/+spec/new-upload-workflow

Context

We want to make a Glance API endpoint public to enable end-user (not admin) upload of images.

Problems This Introduces

Making a Glance API endpoint public causes these problems:

• need some kind of quality control on what's being stuffed into glance as "images"
  • this enhances end-user experience (so you don't keep trying to boot an uploaded movie or something -- want to reject bad images before this point if possible)
• don't want the extra bandwidth, processing requirements of these uploads to interfere with normal glance functionality as an image source for nova
  • want to be able to push the upload, validation process out to the cloud periphery

"Import"

We propose to introduce an end-user upload-type operation called "import".

An objection to this proposal is that Glance v1 has "copy-from" and "location" ... why aren't these sufficient?

Difference between "import" and "copy-from":

• copy-from: you've got an Image (capital "I") to upload
• import: you've got some bits that you want turned into an Image

(In other words, we can trust nova but don't know about ordinary glance "users")

Difference between "import" and "location":

• location: you've got an Image stored elsewhere; glance grabs the bits from there when the Image is requested
• import: you've got some bits stored elsewhere, but there's no way to know whether they are an "Image"

So, for these reasons, we will introduce an import operation.