Develop tagging scheme

[lgrosz]

Yocto supports various distros and versions. Yocto itself has different versions. Come up with a tagging scheme which supports all of these cases.

[lgrosz]

Schema proposal...

yocto_<distro>:<yocto-version>_<distro-version>

For example

• Tagged yocto version, yocto_ubuntu:4.1.2_20.04
• Named (living) yocto version, yocto_ubuntu:langdale_20.04

Philosophically, the label would be the combination of "yocto" and the Linux distribution name, which is likely the label of the base image. The tag would be the combination of the yocto version and the Linux distribution version, which is likely the tag of the base image.

One reason this may not be desired is the base distributions likely won't be changing during the lifecycle of a yocto version, so it may not make sense for the tag to be the combination of versions. Rather a scheme like yocto_<distro-and-version>:<yocto-version>, e.g. yocto_ubuntu-20.04:4.1.3, could be used. This may be more applicable to the user who mostly will care about what version of yocto they can build with the container.