kaniko: HTTP 401 returned when trying to push to Dockerhub with correct credentials

Actual behavior While running a build with correct and valid docker credentials mounted under /kaniko/.docker/config.json and the environment variable DOCKER_CONFIG=/kaniko/.docker, Kaniko fails to pass the “push” permission test to Dockerhub, throwing the error:

error checking push permissions -- make sure you entered the correct tag name, and that you are authenticated correctly, and try again: checking push permission for "index.docker.io/myname/kaniko-test:latest": UNAUTHORIZED: authentication required; [map[Type:repository Class: Name:myname/kaniko-test Action:pull] map[Type:repository Class: Name:myname/kaniko-test Action:push]]

NOTE: The “config.json” has confirmed to be valid by running docker --config docker/ build -t myname/testing-push . (with the config pointed to the same file) and confirming that this authenticated successfully against Dockerhub.

Expected behavior That the Build successfully authenticates against Dockerhub

NOTE: This might be related to an issue in an upstream dependency as per: https://github.com/GoogleContainerTools/kaniko/issues/614

To Reproduce Run the following command to build an image and push to a Dockerhub repository you have permissions to, with the Dockerhub “config.json” file under the “docker” directory:

docker run \
  -v /path/to/code/kaniko-test:/workspace \
  -v docker:/kaniko/.docker \
  --env DOCKER_CONFIG=/kaniko/.docker \
  gcr.io/kaniko-project/executor:debug \
  --dockerfile /workspace/Dockerfile \
  --destination yourname/kaniko-test:latest \
  --context dir:///workspace/ \
  --cache=false

Additional Information

• Dockerfile

FROM nginx

RUN ls -al
RUN ls -al /root/
#RUN ls -al /root/.docker/
#RUN cat /root/.docker/config.json
RUN ls -al /kaniko
RUN ls -al /kaniko/.docker/
RUN cat /kaniko/.docker/config.json

• Build Context sample config.json (secret removed):

{
	"auths": {
		"https://index.docker.io/v1/": {
      "email": "foo@bar.com",
      "auth": "ABCDEFGHIJKLMNOP"
    }
	}
}

• Kaniko Image (fully qualified with digest) Not sure. Latest debug one?