[Feature Request] Add license to Image Metadata as mandatory attribute

[anjastrunk]

Image metadata support information about

• license_included (boolean) indicates whether or not the flavor fee includes the licenses required to use this image.
• license_required (boolean) indicates whether or not a customer must bring its own license to be license compliant.

Beside these information, content of image's license would be important for customers. Especially, if image includes a non popular operating system.
I suggest to add an additional metadata called license as mandatory metadata license MUST refer to a SPDX identifiers or URL to license document.

[berendt]

Makes sense to me. I think it is a good idea to also have the license metadata as MUST.

[garloff]

If you read the current standard as a user you could conclude that you can use the image without any extra fees if license_required is not true. (If you want maintenance, you need to also ensure subscription_required is not true.)

It would be nice to explicitly state a license for an image.
However, to the best of my knowledge, no such thing exists.
A Linux distribution is a collection of software which may be under a variety of licenses.
The distributor's job is to ensure that
(a) no included software interacts with other included software that is not allowed by the license, e.g. linking proprietary code to GPL code
(b) users have the right to use all included software -- if special strings are attached, display the EULAs in the install process
(c) the whole thing can be distributed

To my knowledge, there is no nice solution for (b) with images, so public images should not include software that requires EULAs to be displayed.
The image builder needs to take care of (a) and (c).

If we wanted to, we could try to collect a list of licenses of all code included in images and then have a long list in the license metadata. To my knowledge noone is doing this currently. If we go there, we should be aware that this is non-trivial to get right, technically and legally.