route0/util/experiment.py

110 lines
3.9 KiB
Python

"""The experiment module is responsible for collecting topology and scenario
settings.
"""
import importlib
import os
import sys
class Experiment:
"""Class that describes a network experiment. An experiment is a
particular combination of topology and scenario.
A topology determines the nodes and their links in the network.
A scenario determines which daemons need to be started on which nodes and
the location of the relevant config files.
"""
def __init__(self, topology, scenario):
root_dir = os.path.dirname(sys.modules['__main__'].__file__)
# Check if the topology directory exists.
topo_dir = os.path.join(root_dir, "topology/{}".format(topology))
if not os.path.exists(topo_dir):
raise KeyError("Topology \"{}\" not supported".format(topology))
# Extract the topology class.
self._topo = (importlib
.import_module('topology.{}.topo'.format(topology))
.NetTopo)
# Initialise list of daemons.
self.daemons = []
# Default scenario script is none which applies to both plain and basic.
# The difference between the two is that basic will continue and launch
# zebra and staticd before returning.
self._scenario_script = None
# Return now if the scenario is "plain".
if scenario == "plain":
return
# Check if the scenario directory exists. If it does work out which
# daemons are to be used and on which nodes. If the scenario is
# "basic" skip this step.
if scenario != "basic":
scenario_dir = os.path.join(topo_dir,
"scenario/{}".format(scenario))
if not os.path.exists(scenario_dir):
raise KeyError("Scenario \"{}\" not supported"
.format(scenario))
# Work out which daemons to start and their config directories.
for daemon in os.listdir(scenario_dir):
self._get_daemon_nodes(scenario_dir, daemon)
# If there is a scenario.py in the directory import the script
# function from it.
if os.path.exists(os.path.join(scenario_dir, "scenario.py")):
self._scenario_script = (
importlib
.import_module("topology.{}.scenario.{}.scenario"
.format(topology, scenario))
.script
)
# Zebra and staticd daemons are special. If they don't have an
# override in the scenario directory, take the defaults from the
# topology directory.
for daemon in ["zebra", "staticd"]:
if not hasattr(self, daemon):
self._get_daemon_nodes(topo_dir, daemon)
def _get_daemon_nodes(self, parent_dir, daemon):
# Each daemon entry should be a directory.
daemon_dir = os.path.join(parent_dir, daemon)
if os.path.exists(daemon_dir) and os.path.isdir(daemon_dir):
# Make sure zebra is always first on the list of daemons.
if daemon == "zebra":
self.daemons.insert(0, daemon)
else:
self.daemons.append(daemon)
setattr(self, daemon, set())
setattr(self, "{}_conf".format(daemon), daemon_dir)
# Each node running this daemons must have a conf file in the
# daemon directory called <node_name>.conf.
for conf in os.listdir(daemon_dir):
# Make sure we're only dealing with conf files.
if conf.endswith(".conf"):
getattr(self, daemon).add(conf.split('.')[0])
@property
def topo(self):
"""The topology of this scenario.
"""
return self._topo
@property
def script(self):
"""The script to run after the daemons have been started.
"""
return self._scenario_script