def METHOD_NAME(name, env):
    """
    get environment variable related with an image according to the priority:
    1. IMAGE_<name>_<env>
    2. IMAGE_<env>
    the image name will be automatically converted to the unserscore_uppsercase
    format, for example, "chaos-mesh" will be converted to "CHAOS_MESH"
    """
    default_env = os.getenv("IMAGE_" + env)
    env_mid_name = utils.underscore_uppercase(name)
    env = os.getenv(f"IMAGE_{env_mid_name}_{env}", default_env)
    if env == "":
        env = default_env
    return env