Files
notifications-api/app/delivery/send_to_providers.py
Chris Hill-Scott 6900505b05 Don’t call random.choices with zero weighting
As of 041d8b48a2
it’s not valid to call `random.choices` without giving at least one of
the options a positive weighting.

This makes sense, because giving a zero weighting is effectively saying
‘theres’s only one choice, but don’t choose it’.

In our codebase this is applicable where there’s only one international
provider, which we want to use even when it’s been de-prioritised for
domestic SMS.

This doesn’t cause a problem now, but will if we upgrade to Python
versions greater than 3.9.0.
2021-08-31 11:08:27 +01:00

239 lines
8.5 KiB
Python

import random
from datetime import datetime, timedelta
from urllib import parse
from cachetools import TTLCache, cached
from flask import current_app
from notifications_utils.template import (
HTMLEmailTemplate,
PlainTextEmailTemplate,
SMSMessageTemplate,
)
from app import create_uuid, notification_provider_clients, statsd_client
from app.celery.research_mode_tasks import (
send_email_response,
send_sms_response,
)
from app.dao.email_branding_dao import dao_get_email_branding_by_id
from app.dao.notifications_dao import dao_update_notification
from app.dao.provider_details_dao import (
dao_reduce_sms_provider_priority,
get_provider_details_by_notification_type,
)
from app.exceptions import NotificationTechnicalFailureException
from app.models import (
BRANDING_BOTH,
BRANDING_ORG_BANNER,
EMAIL_TYPE,
KEY_TYPE_TEST,
NOTIFICATION_SENDING,
NOTIFICATION_SENT,
NOTIFICATION_STATUS_TYPES_COMPLETED,
NOTIFICATION_TECHNICAL_FAILURE,
SMS_TYPE,
)
from app.serialised_models import SerialisedService, SerialisedTemplate
def send_sms_to_provider(notification):
service = SerialisedService.from_id(notification.service_id)
if not service.active:
technical_failure(notification=notification)
return
if notification.status == 'created':
provider = provider_to_use(SMS_TYPE, notification.international)
template_model = SerialisedTemplate.from_id_and_service_id(
template_id=notification.template_id, service_id=service.id, version=notification.template_version
)
template = SMSMessageTemplate(
template_model.__dict__,
values=notification.personalisation,
prefix=service.name,
show_prefix=service.prefix_sms,
)
created_at = notification.created_at
key_type = notification.key_type
if service.research_mode or notification.key_type == KEY_TYPE_TEST:
update_notification_to_sending(notification, provider)
send_sms_response(provider.get_name(), str(notification.id), notification.to)
else:
try:
provider.send_sms(
to=notification.normalised_to,
content=str(template),
reference=str(notification.id),
sender=notification.reply_to_text,
international=notification.international
)
except Exception as e:
notification.billable_units = template.fragment_count
dao_update_notification(notification)
dao_reduce_sms_provider_priority(provider.get_name(), time_threshold=timedelta(minutes=1))
raise e
else:
notification.billable_units = template.fragment_count
update_notification_to_sending(notification, provider)
delta_seconds = (datetime.utcnow() - created_at).total_seconds()
statsd_client.timing("sms.total-time", delta_seconds)
if key_type == KEY_TYPE_TEST:
statsd_client.timing("sms.test-key.total-time", delta_seconds)
else:
statsd_client.timing("sms.live-key.total-time", delta_seconds)
if service.high_volume:
statsd_client.timing("sms.live-key.high-volume.total-time", delta_seconds)
else:
statsd_client.timing("sms.live-key.not-high-volume.total-time", delta_seconds)
def send_email_to_provider(notification):
service = SerialisedService.from_id(notification.service_id)
if not service.active:
technical_failure(notification=notification)
return
if notification.status == 'created':
provider = provider_to_use(EMAIL_TYPE)
template_dict = SerialisedTemplate.from_id_and_service_id(
template_id=notification.template_id, service_id=service.id, version=notification.template_version
).__dict__
html_email = HTMLEmailTemplate(
template_dict,
values=notification.personalisation,
**get_html_email_options(service)
)
plain_text_email = PlainTextEmailTemplate(
template_dict,
values=notification.personalisation
)
created_at = notification.created_at
key_type = notification.key_type
if service.research_mode or notification.key_type == KEY_TYPE_TEST:
notification.reference = str(create_uuid())
update_notification_to_sending(notification, provider)
send_email_response(notification.reference, notification.to)
else:
from_address = '"{}" <{}@{}>'.format(service.name, service.email_from,
current_app.config['NOTIFY_EMAIL_DOMAIN'])
reference = provider.send_email(
from_address,
notification.normalised_to,
plain_text_email.subject,
body=str(plain_text_email),
html_body=str(html_email),
reply_to_address=notification.reply_to_text
)
notification.reference = reference
update_notification_to_sending(notification, provider)
delta_seconds = (datetime.utcnow() - created_at).total_seconds()
if key_type == KEY_TYPE_TEST:
statsd_client.timing("email.test-key.total-time", delta_seconds)
else:
statsd_client.timing("email.live-key.total-time", delta_seconds)
if service.high_volume:
statsd_client.timing("email.live-key.high-volume.total-time", delta_seconds)
else:
statsd_client.timing("email.live-key.not-high-volume.total-time", delta_seconds)
def update_notification_to_sending(notification, provider):
notification.sent_at = datetime.utcnow()
notification.sent_by = provider.get_name()
if notification.status not in NOTIFICATION_STATUS_TYPES_COMPLETED:
notification.status = NOTIFICATION_SENT if notification.international else NOTIFICATION_SENDING
dao_update_notification(notification)
provider_cache = TTLCache(maxsize=8, ttl=10)
@cached(cache=provider_cache)
def provider_to_use(notification_type, international=False):
active_providers = [
p for p in get_provider_details_by_notification_type(notification_type, international) if p.active
]
if not active_providers:
current_app.logger.error(
"{} failed as no active providers".format(notification_type)
)
raise Exception("No active {} providers".format(notification_type))
if len(active_providers) == 1:
weights = [100]
else:
weights = [p.priority for p in active_providers]
chosen_provider = random.choices(active_providers, weights=weights)[0]
return notification_provider_clients.get_client_by_name_and_type(chosen_provider.identifier, notification_type)
def get_logo_url(base_url, logo_file):
base_url = parse.urlparse(base_url)
netloc = base_url.netloc
if base_url.netloc.startswith('localhost'):
netloc = 'notify.tools'
elif base_url.netloc.startswith('www'):
# strip "www."
netloc = base_url.netloc[4:]
logo_url = parse.ParseResult(
scheme=base_url.scheme,
netloc='static-logos.' + netloc,
path=logo_file,
params=base_url.params,
query=base_url.query,
fragment=base_url.fragment
)
return parse.urlunparse(logo_url)
def get_html_email_options(service):
if service.email_branding is None:
return {
'govuk_banner': True,
'brand_banner': False,
}
if isinstance(service, SerialisedService):
branding = dao_get_email_branding_by_id(service.email_branding)
else:
branding = service.email_branding
logo_url = get_logo_url(
current_app.config['ADMIN_BASE_URL'],
branding.logo
) if branding.logo else None
return {
'govuk_banner': branding.brand_type == BRANDING_BOTH,
'brand_banner': branding.brand_type == BRANDING_ORG_BANNER,
'brand_colour': branding.colour,
'brand_logo': logo_url,
'brand_text': branding.text,
'brand_name': branding.name,
}
def technical_failure(notification):
notification.status = NOTIFICATION_TECHNICAL_FAILURE
dao_update_notification(notification)
raise NotificationTechnicalFailureException(
"Send {} for notification id {} to provider is not allowed: service {} is inactive".format(
notification.notification_type,
notification.id,
notification.service_id))