Is it normal that image id b7cf8f0d9e82 isn't based on image id 511136ea3c5a (scratch) like the previous ones ?

[gissehel]

Almost all images derivate from image id 511136ea3c5a (which could be labelled scratch, because it's the one choosen when using FROM scratch). At least since some docker version 0.x if I'm not mistaken.

And recently, the ubuntu image b7cf8f0d9e82 (tags: ubuntu:14.04 ubuntu:14.04.2 ubuntu:latest ubuntu:trusty ubuntu:trusty-20150320) didn't derive from "scrach".

Is it a bug in the image creation process ? Or a new direction/convention about root images ?

[tianon]

See the updated description on https://registry.hub.docker.com/_/scratch/, especially the second paragraph:

As of Docker 1.5.0 (specifically, moby/moby#8827), FROM scratch is a no-op in the Dockerfile, and will not create an extra layer in your image (so a previously 2-layer image will be a 1-layer image instead).

[gissehel]

Ok, that address my question !