authentik/passbook/flows/planner.py

77 lines
2.6 KiB
Python

"""Flows Planner"""
from dataclasses import dataclass, field
from time import time
from typing import Any, Dict, List, Tuple
from django.http import HttpRequest
from structlog import get_logger
from passbook.flows.exceptions import EmptyFlowException, FlowNonApplicableException
from passbook.flows.models import Flow, Stage
from passbook.policies.engine import PolicyEngine
LOGGER = get_logger()
PLAN_CONTEXT_PENDING_USER = "pending_user"
PLAN_CONTEXT_SSO = "is_sso"
@dataclass
class FlowPlan:
"""This data-class is the output of a FlowPlanner. It holds a flat list
of all Stages that should be run."""
stages: List[Stage] = field(default_factory=list)
context: Dict[str, Any] = field(default_factory=dict)
def next(self) -> Stage:
"""Return next pending stage from the bottom of the list"""
return self.stages[0]
class FlowPlanner:
"""Execute all policies to plan out a flat list of all Stages
that should be applied."""
flow: Flow
def __init__(self, flow: Flow):
self.flow = flow
def _check_flow_root_policies(self, request: HttpRequest) -> Tuple[bool, List[str]]:
engine = PolicyEngine(self.flow.policies.all(), request.user, request)
engine.build()
return engine.result
def plan(self, request: HttpRequest) -> FlowPlan:
"""Check each of the flows' policies, check policies for each stage with PolicyBinding
and return ordered list"""
LOGGER.debug("Starting planning process", flow=self.flow)
start_time = time()
plan = FlowPlan()
# First off, check the flow's direct policy bindings
# to make sure the user even has access to the flow
root_passing, root_passing_messages = self._check_flow_root_policies(request)
if not root_passing:
raise FlowNonApplicableException(root_passing_messages)
# Check Flow policies
for stage in (
self.flow.stages.order_by("flowstagebinding__order")
.select_subclasses()
.select_related()
):
binding = stage.flowstagebinding_set.get(flow__pk=self.flow.pk)
engine = PolicyEngine(binding.policies.all(), request.user, request)
engine.build()
passing, _ = engine.result
if passing:
LOGGER.debug("Stage passing", stage=stage)
plan.stages.append(stage)
end_time = time()
LOGGER.debug(
"Finished planning", flow=self.flow, duration_s=end_time - start_time
)
if not plan.stages:
raise EmptyFlowException()
return plan