Docker version 1.12
Docker registry version 2
Operating system ubuntu14.04
docker save command to export local image
myubuntu,I got myubuntu.tar. After decompressing myubuntu.tar, I got the manifest.json like figure 1.figure 1 manifest.json. I cannnot understand the meaning of
layers key of this file. I compared this
manifest I got from the registry v2 api(I have pushed this image to my own registry service). The manifest I got from registry is like manifest from registry. Obviously,
manifest use different IDs. The id in
manifest.json is not
blobsum which means the sha256 digest of
compressed layer data. And it’s not
diffid which means the sha256 digest of
uncompressed layer data(I have checked the configure json of this image.).
So, what does layers of
manifest.json mean and how to calculate it?