DOCKER_REGISTRY_URL = "https://dockerregistry:443"
DOCKER_REGISTRY_CREDENTIALS = 'myuser'

node('docker') {
    stage 'checkout'
    checkout scm

    stage 'build'
    echo "${DOCKER_REGISTRY_URL}, ${DOCKER_REGISTRY_CREDENTIALS}"

    docker.withRegistry(DOCKER_REGISTRY_URL, DOCKER_REGISTRY_CREDENTIALS)
    {
        def img = docker.build('myuser/img-deps:14.04', '14.04')
        img.push()
    }
}

docker tag --force=true myuser/img-deps:14.04 dockerregistry/myuser/img-deps:14.04
Warning: '--force' is deprecated, it will be removed soon. See usage.
[Pipeline] sh
[master] Running shell script
+ docker push dockerregistry/myuser/img-deps:14.04
The push refers to a repository [docker.io/dockerregistry/myuser/img-deps]
c3644055bd1d: Preparing
...
81a9ec52d927: Preparing
unauthorized: authentication required
[Pipeline] }
[Pipeline] // withDockerRegistry
...
[Pipeline] // node
[Pipeline] End of Pipeline
ERROR: script returned exit code 1
Finished: FAILURE