private AuthConfig parseUser(String userName, Map user) {
        if (user == null) {
            return null;
        }
        String token = (String) user.get("token");
        if (token == null) {
            return null;
        }

        // Strip off stuff after username
        Matcher matcher = Pattern.compile("^([^/]+).*$").matcher(userName);
        return new AuthConfig(matcher.matches() ? matcher.group(1) : userName,
                              token, null, null);
    }
Try using the AWS credentials provided via ENV variables.
See https://docs.aws.amazon.com/cli/latest/userguide/cli-configure-envvars.html
src/main/java/io/fabric8/maven/docker/util/AuthConfigFactory.java