def validate_conf(app, required_vars):
    """
    Ensures that the given fields are set in the applications conf.

    :param app:
    :param required_vars: list
    """
    for var in required_vars:
        if var not in app.config:
            raise InvalidConfiguration(
                f"Required variable '{var}' is not set in Lemur's conf."
            )

    Ensures that the given fields are set in the applications conf.

    :param app:
    :param required_vars: list
    
lemur/common/utils.py