Bug: Docker Multistage Build labeled stage is not detected

[Xyaren]

Description

Mutlistage Docker Build is failing if named stage is used as a base later:

Info

• docker-maven-plugin version: 0.34.1
• maven verison: 3.6.3

Example Dockerfile:

FROM centos AS first

RUN ls -la /

FROM centos as second

RUN ls -la /

# this fails
FROM second

RUN ls -la /

Error:

Failed to execute goal io.fabric8:docker-maven-plugin:0.34.1:build (build-docker) on project xxx-my-project-xxx Unable to pull 'second:latest' : {"message":"pull access denied for second, repository does not exist or may require 'docker login': denied: requested access to the resource is denied"} (Not Found: 404)

[davoustp]

Hi,
I agree with this report: the plugin fails because it attempts to pull any FROM image regardless of it being a named image (using FROM ... AS <name>) declared upstream in a multi-stage build.
This is actually a regression because it was previously working with version 0.28.0.

A simple project exhibiting the issue is attached to ease reproducing the issue:
maven-docker-plugin-fails-with-named-build-stages.tar.gz

Trying to narrow the problem down shows that building with plugin version 0.28.0 passes with flying color when it fails quick & hard with plugin version 0.29.0.

Scanning through the 0.29.0 changelog hints that pull request #1057 is probably the culprit: instead of attempting to pull the first base image only, it attempts to do so with each and every base image (declared with FROM) without checking that the image may be a reference to an already declared and named build stage if it does not declare an alias on itself (found after investigation).

[rohanKanojia]

@davoustp : Thanks for the investigation, Would it be possible to submit a fix for this issue?

[davoustp]

Forking now and checking what can be done.

[rohanKanojia]

@davoustp : Thanks a lot!

[davoustp]

Done. Sonar analysis fails as it looks it required more permission than I have.

[rohanKanojia]

Don't worry about it, our sonar job is failing right now due to removal of sonarcube token. I'll probably remove it or add new token