Add a label with a distribution ID #110
Description
bootc-image-builder will soon gain the ability of building an installer ISO for bootable container.
This comes with an interesting challenge: For Fedora, we use a Fedora installer, but for CentOS, we should probably use a CentOS one.
However, in order to find out what distribution is inside the bootable container, we would currently need to introspect the image to read /etc/os-release. This is surely possible, but it would be quite convenient to just read it from the labels. We fetch the labels much sooner in the image build process before fetching the whole container image. Generally speaking, the ability to know which distribution is inside the container based on its labels feels quite natural to me.
Would it be possible to add a label to the containers with the distribution ID? My suggestion is to just take ID from /etc/os-release and make it a label. VERSION_ID might be also nice.