mrr_tasks.py

@APP.task(base=ErrorHandler)
def calc_mrr():
    mrr_chord = chord(
        chain(get_resources.s(key), calc_revenue.s())
        for key in mrr_stacks
    )
    return mrr_chord(mrr_total.s())  # mrr_total receives a list of AsyncResult
                                     # but I need the actual results (the output of calc_revenue,
                                     # which is the values returned by _sum_revenues)


@APP.task(base=ErrorHandler, ignore_result=False)
def get_resources(key):
    return {}


@APP.task(base=ErrorHandler, ignore_result=False)
def calc_revenue(res_dict):
    calc_chord = chord(
        calc_resource_revenue.s(...)
        for resource in res_dict.get('resources', [])
    )
    return calc_chord(_sum_revenues.s())  # _sum_revenues receives a list a ints and returns a single int. Great! =D


@APP.task(base=ErrorHandler, ignore_result=False)
def _sum_revenues(revenues):
    return sum(revenues)


@APP.task(base=ErrorHandler, ignore_result=False)
def calc_resource_revenue(resource, tenant_id, region):
    return 1


@APP.task(base=ErrorHandler, ignore_result=False)
def mrr_total(revenues):
    return round(sum(revenues), 2)