def generate_service_obs(n):
    """
    Recursively generate list of all possible configurations of n services.
    Same as generate_service_configs except replace True/False with "yes"/"no"
    """
    # base cases
    if n <= 0:
        return []
    if n == 1:
        return ["yes", "no"]

    perms = []
    for p in generate_service_obs(n - 1):
        perms.append("yes" + p)
        perms.append("no" + p)
    return perms