flows: add caching of plan, add planner unittests

This commit is contained in:
Jens Langhammer 2020-05-11 11:39:58 +02:00
parent 10cb412532
commit 6fd19c0a37
3 changed files with 103 additions and 4 deletions

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@ -1,11 +1,13 @@
"""Flows Planner""" """Flows Planner"""
from dataclasses import dataclass, field from dataclasses import dataclass, field
from time import time from time import time
from typing import Any, Dict, List, Tuple from typing import Any, Dict, List, Optional, Tuple
from django.core.cache import cache
from django.http import HttpRequest from django.http import HttpRequest
from structlog import get_logger from structlog import get_logger
from passbook.core.models import User
from passbook.flows.exceptions import EmptyFlowException, FlowNonApplicableException from passbook.flows.exceptions import EmptyFlowException, FlowNonApplicableException
from passbook.flows.models import Flow, Stage from passbook.flows.models import Flow, Stage
from passbook.policies.engine import PolicyEngine from passbook.policies.engine import PolicyEngine
@ -16,6 +18,14 @@ PLAN_CONTEXT_PENDING_USER = "pending_user"
PLAN_CONTEXT_SSO = "is_sso" PLAN_CONTEXT_SSO = "is_sso"
def cache_key(flow: Flow, user: Optional[User] = None) -> str:
"""Generate Cache key for flow"""
prefix = f"flow_{flow.pk}"
if user:
prefix += f"#{user.pk}"
return prefix
@dataclass @dataclass
class FlowPlan: class FlowPlan:
"""This data-class is the output of a FlowPlanner. It holds a flat list """This data-class is the output of a FlowPlanner. It holds a flat list
@ -34,9 +44,11 @@ class FlowPlanner:
"""Execute all policies to plan out a flat list of all Stages """Execute all policies to plan out a flat list of all Stages
that should be applied.""" that should be applied."""
use_cache: bool
flow: Flow flow: Flow
def __init__(self, flow: Flow): def __init__(self, flow: Flow):
self.use_cache = True
self.flow = flow self.flow = flow
def _check_flow_root_policies(self, request: HttpRequest) -> Tuple[bool, List[str]]: def _check_flow_root_policies(self, request: HttpRequest) -> Tuple[bool, List[str]]:
@ -48,13 +60,17 @@ class FlowPlanner:
"""Check each of the flows' policies, check policies for each stage with PolicyBinding """Check each of the flows' policies, check policies for each stage with PolicyBinding
and return ordered list""" and return ordered list"""
LOGGER.debug("f(plan): Starting planning process", flow=self.flow) LOGGER.debug("f(plan): Starting planning process", flow=self.flow)
start_time = time()
plan = FlowPlan(flow_pk=self.flow.pk.hex)
# First off, check the flow's direct policy bindings # First off, check the flow's direct policy bindings
# to make sure the user even has access to the flow # to make sure the user even has access to the flow
root_passing, root_passing_messages = self._check_flow_root_policies(request) root_passing, root_passing_messages = self._check_flow_root_policies(request)
if not root_passing: if not root_passing:
raise FlowNonApplicableException(root_passing_messages) raise FlowNonApplicableException(root_passing_messages)
cached_plan = cache.get(cache_key(self.flow, request.user), None)
if cached_plan and self.use_cache:
LOGGER.debug("f(plan): Taking plan from cache", flow=self.flow)
return cached_plan
start_time = time()
plan = FlowPlan(flow_pk=self.flow.pk.hex)
# Check Flow policies # Check Flow policies
for stage in ( for stage in (
self.flow.stages.order_by("flowstagebinding__order") self.flow.stages.order_by("flowstagebinding__order")
@ -66,7 +82,7 @@ class FlowPlanner:
engine.build() engine.build()
passing, _ = engine.result passing, _ = engine.result
if passing: if passing:
LOGGER.debug("f(plan): Stage passing", stage=stage) LOGGER.debug("f(plan): Stage passing", stage=stage, flow=self.flow)
plan.stages.append(stage) plan.stages.append(stage)
end_time = time() end_time = time()
LOGGER.debug( LOGGER.debug(
@ -74,6 +90,7 @@ class FlowPlanner:
flow=self.flow, flow=self.flow,
duration_s=end_time - start_time, duration_s=end_time - start_time,
) )
cache.set(cache_key(self.flow, request.user), plan)
if not plan.stages: if not plan.stages:
raise EmptyFlowException() raise EmptyFlowException()
return plan return plan

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@ -0,0 +1,82 @@
"""flow planner tests"""
from unittest.mock import MagicMock, patch
from django.shortcuts import reverse
from django.test import RequestFactory, TestCase
from guardian.shortcuts import get_anonymous_user
from passbook.flows.exceptions import EmptyFlowException, FlowNonApplicableException
from passbook.flows.models import Flow, FlowDesignation, FlowStageBinding
from passbook.flows.planner import FlowPlanner
from passbook.stages.dummy.models import DummyStage
POLICY_RESULT_MOCK = MagicMock(return_value=(False, [""],))
TIME_NOW_MOCK = MagicMock(return_value=3)
class TestFlowPlanner(TestCase):
"""Test planner logic"""
def setUp(self):
self.request_factory = RequestFactory()
def test_empty_plan(self):
"""Test that empty plan raises exception"""
flow = Flow.objects.create(
name="test-empty",
slug="test-empty",
designation=FlowDesignation.AUTHENTICATION,
)
request = self.request_factory.get(
reverse("passbook_flows:flow-executor", kwargs={"flow_slug": flow.slug}),
)
request.user = get_anonymous_user()
with self.assertRaises(EmptyFlowException):
planner = FlowPlanner(flow)
planner.plan(request)
@patch(
"passbook.flows.planner.FlowPlanner._check_flow_root_policies",
POLICY_RESULT_MOCK,
)
def test_non_applicable_plan(self):
"""Test that empty plan raises exception"""
flow = Flow.objects.create(
name="test-empty",
slug="test-empty",
designation=FlowDesignation.AUTHENTICATION,
)
request = self.request_factory.get(
reverse("passbook_flows:flow-executor", kwargs={"flow_slug": flow.slug}),
)
request.user = get_anonymous_user()
with self.assertRaises(FlowNonApplicableException):
planner = FlowPlanner(flow)
planner.plan(request)
@patch("passbook.flows.planner.time", TIME_NOW_MOCK)
def test_planner_cache(self):
"""Test planner cache"""
flow = Flow.objects.create(
name="test-cache",
slug="test-cache",
designation=FlowDesignation.AUTHENTICATION,
)
FlowStageBinding.objects.create(
flow=flow, stage=DummyStage.objects.create(name="dummy"), order=0
)
request = self.request_factory.get(
reverse("passbook_flows:flow-executor", kwargs={"flow_slug": flow.slug}),
)
request.user = get_anonymous_user()
planner = FlowPlanner(flow)
planner.plan(request)
self.assertEqual(TIME_NOW_MOCK.call_count, 2) # Start and end
planner = FlowPlanner(flow)
planner.plan(request)
self.assertEqual(
TIME_NOW_MOCK.call_count, 2
) # When taking from cache, time is not measured