Kaniko multi-stage dockerfile build issue

[harshadjoshi619]

Actual behavior
I am using kaniko-project/executor:v1.17.0-slim in my tekton pipeline. In case of normal dockerfiles it is working as expected but when we try with multi-stage dockerfiles it is giving me below error:

error pushing image: failed to push to destination ".../.../" UNAUTHORISED user is unauthorised to upload to ".../.../"

Expected behavior
Kaniko should upload multi-stage dockerfile image to artifactory

To Reproduce
Steps to reproduce the behavior:

1. create a dockerfile with multiple FROM statements in it
2. use kaniko version as kaniko-project/executor:v1.17.0-slim

Additional Information

I am already using /kaniko/.docker to store my credentials. Still facing same issue.

Kindly suggest some way to overcome this issue.

Triage Notes for the Maintainers

Description	Yes/No
Please check if this a new feature you are proposing
Please check if the build works in docker but not in kaniko
Please check if this error is seen when you use --cache flag
Please check if your dockerfile is a multistage dockerfile

[aaron-prindle]

@harshadjoshi619 thanks for flagging this issue. To help debug this, can you post the entire logs from the failing run (with any sensitive info redacted), preferably running with verbose logs - eg: --verbosity=debug. If you have a small repro docker file/repro-project that would be helpful as well. Currently I am a bit confused if the issue here is referring to kaniko not being able to push multi-stage images to JFrog Artifactory or if kaniko is not able to pull down intermediate FROM images in a multi-stage build from JFrog Artifactory

[frami]

I have the same problem. I found out, that kaniko deletes the docker configuration file in /root/.docker. I think it's the same issue as #2764

[atorrembo]

Maybe related to #2576 ?

[zijiwork]

What progress has been made

[mzihlmann]

kaniko removes everything outside of the /kaniko dir when switching over to the second build stage, so if your credentials are stored outside this directory they are indeed gone. You can safe a file across boundaries by putting it on the ingore list:
https://github.com/GoogleContainerTools/kaniko#flag---ignore-path

--ignore-path=/root/.netrc

as an example