Different SHA 256 Digest when using CLI and SDK

[mikemhenry]

I get two different sha256 digests when pulling docker.io/library/alpine:latest

When using CLI I get
sha256:a75afd8b57e7f34e4dad8d65e2c7ba2e1975c795ce1ee22fa34f8cf46f96a3be

When using the SDK I get
sha256:28f6e27057430ed2a40dbdd50d2736a3f0a295924016e294938110eeb8439818

I thought it may be related to: docker/hub-feedback#1925

But when I try and pull the image reported by the SDK I get:

$ docker pull docker.io/library/alpine@sha256:28f6e27057430ed2a40dbdd50d2736a3f0a295924016e294938110eeb8439818
Error response from daemon: received unexpected HTTP status: 500 Internal Server Error

So I am unable to inspect the potential differences with the CLI.

Steps to reproduce:

CLI

docker pull docker.io/library/alpine:latest
latest: Pulling from library/alpine
Digest: sha256:a75afd8b57e7f34e4dad8d65e2c7ba2e1975c795ce1ee22fa34f8cf46f96a3be
Status: Image is up to date for alpine:latest
docker.io/library/alpine:latest

SDK

>>> import docker
>>> client = docker.from_env()
>>> container = client.images.pull("docker.io/library/alpine", tag="latest")
>>> container.id
'sha256:28f6e27057430ed2a40dbdd50d2736a3f0a295924016e294938110eeb8439818'

OS, python, docker info:

$ pip freeze | grep docker && python --version && docker version
docker==4.4.3
Python 3.8.6
Client:
 Version:           19.03.13
 API version:       1.40
 Go version:        go1.13.8
 Git commit:        4484c46
 Built:             Fri Dec 18 12:00:51 2020
 OS/Arch:           linux/amd64
 Experimental:      false

Server:
 Engine:
  Version:          19.03.13
  API version:      1.40 (minimum version 1.12)
  Go version:       go1.13.8
  Git commit:       4484c46
  Built:            Fri Dec  4 23:02:49 2020
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.3.7-0ubuntu3.2
  GitCommit:        
 runc:
  Version:          spec: 1.0.1-dev
  GitCommit:        
 docker-init:
  Version:          0.18.0
  GitCommit: 

$ cat /etc/os-release
NAME="Pop!_OS"
VERSION="20.10"
ID=pop
ID_LIKE="ubuntu debian"
PRETTY_NAME="Pop!_OS 20.10"
VERSION_ID="20.10"
HOME_URL="https://pop.system76.com"
SUPPORT_URL="https://support.system76.com"
BUG_REPORT_URL="https://github.com/pop-os/pop/issues"
PRIVACY_POLICY_URL="https://system76.com/privacy"
VERSION_CODENAME=groovy
UBUNTU_CODENAME=groovy
LOGO=distributor-logo-pop-os

[feliperuhland]

Hi @mikemhenry

The object that returns from client.images.pull("docker.io/library/alpine", tag="latest") is an Image Object and the id attribute is from the image.

To get the digest hash you have to access the attrs dict and get the RepoDigests key.

>>> image = cli.images.pull("docker.io/library/alpine", tag="latest")
>>> image
<Image: 'alpine:latest'>
>>> image.attrs.get("RepoDigests")
['alpine@sha256:a75afd8b57e7f34e4dad8d65e2c7ba2e1975c795ce1ee22fa34f8cf46f96a3be']

[mikemhenry]

Thank you very much! Sorry for the superfluous issue.