Permission denied error with Docker Update Module

Hi @mirzak, @lluiscampos
I changed the permission of that config.json to the current user i use, and I ran

./docker-artifact-gen -n {ARTIFACT_NAME} -t {DEVICE_TYPE} -o {OUTPUT_PATH} {DOCKER_IMAGES}
but I got this error this time,

./docker-artifact-gen: line 116: meta-data.json: Permission denied