private AuthConfig createAuthConfig(boolean isPush, String user, String registry, RegistryConfig config)
            throws MojoExecutionException {

        return config.createAuthConfig(isPush, user, registry);
    }
Check an image, and, if <code>autoPull</code> is set to true, fetch it. Otherwise if the image
 is not existent, throw an error

@param image image which is required to be pulled
@param pullManager image pull manager
@param registryConfig registry configuration
@param buildImageConfiguration image build configuration
@throws DockerAccessException in case of error in contacting docker daemon
@throws MojoExecutionException in case of any other misc failure
src/main/java/io/fabric8/maven/docker/service/RegistryService.java