Source code for stressor.session_manager

# -*- coding: utf-8 -*-
# (c) 2020-2023 Martin Wendt and contributors; see
# Licensed under the MIT license:
import re
import time
from copy import deepcopy

import requests
from snazzy import red, yellow

from stressor.config_manager import replace_var_macros
from stressor.context_stack import ContextStack
from stressor.plugins.base import ActivityAssertionError
from stressor.util import (

[docs]class StoppedError(StressorError): """Raised when an activity stops due because the `stop_request` is set."""
[docs]class SkippedError(StressorError): """Raised when an activity is skipped due to `max_errors` or `max_time`."""
[docs]class User: def __init__(self, name, password, **kwargs): = name self.password = password for arg_name, arg_val in kwargs.items(): assert type(arg_name) in (int, float, str) setattr(self, arg_name, arg_val) return def __str__(self): return "User<{}>".format( # Provide nicer display for pprint(), etc. __repr__ = __str__ @property def auth(self): """Return (name, password) tuple or None.""" if self.password is None: return None return (, self.password)
[docs]class SessionHelper: """Passed to script activities.""" def __init__(self, session): self.__session = session @property def browser(self): return self.__session.browser_session def __repr__(self): return f"SessionHelper<{self.__session.session_id}>"
[docs]class SessionManager: """ Run a scenario in a single session. """ # #: (float) # DEFAULT_REQUEST_TIMEOUT = 10.0 def __init__(self, run_manager, context, session_id, user): # check_arg(run_manager, RunManager) check_arg(context, dict) check_arg(session_id, str) check_arg(user, User, or_none=True) #: The :class:`RunManager` object that holds global settings and definitions self.run_manager = run_manager config = run_manager.config_manager.config # (dict) Global variables for this session. Initialized from the # run configuration, but not shared between sessions. # (`self.context` is accessible by the respective property below.) context = context.copy() #: (str) Unique ID string for this session self.session_id = session_id #: The :class:`User` object that is assigned to this session self.user = user or User("anonymous", "") #: (dict) Copy of `run_config.sessions` configuration self.sessions = run_manager.config_manager.sessions.copy() #: (dict) Activities can store per-session data here. #: Note that the activity objects are instintiated only once and shared #: by all sessions. = {} #: (bool) True: only simulate activities self.dry_run = bool(context.get("dry_run")) #: (int) Verbosity 0..5 self.verbose = context.get("verbose", 3) #: (:class:`threading.Event`) self.stop_request = run_manager.stop_request # Set some default entries in context dict # context.setdefault("timeout", self.DEFAULT_REQUEST_TIMEOUT) context.setdefault("session_id", self.session_id) context.setdefault("user", self.user) #: The :class:`~stressor.context_stack.ContextStack` object that reflects the current execution path self.context_stack = ContextStack(run_manager.host_id, context) self.context_stack.push(run_manager.process_id) self.context_stack.push(session_id) #: :class:`~stressor.statistic_manager.StatisticManager` object that containscurrent execution path self.stats = run_manager.stats # Lazy initialization using a property self._browser_session = None #: (int) Stop session if global error count > X #: Passing `--max-errors` will override this. self.max_errors = int(config.get("max_errors", 0)) #: (float) Stop session if total run time > X seconds. #: Passing `--max-time` will override this. self.max_time = float(config.get("max_time", 0.0)) self._cancelled_seq = None # Used by StatisticsManager self.pending_sequence = None self.sequence_start = None self.pending_activity = None self.activity_start = None self.stats.register_session(self) def __str__(self): return "SessionManager<{}>".format(self.session_id) # Provide nicer display for pprint(), etc. __repr__ = __str__
[docs] def publish(self, channel, *args, **kwargs): kwargs["session_id"] = self.session_id return self.run_manager.publish(channel, *args, **kwargs)
[docs] def _evaluate_macros(self, kwargs, context): replace_var_macros(kwargs, context) return kwargs
[docs] def make_session_helper(self): """Return a :class:`SessionHelper` instance for this session.""" res = SessionHelper(self) return res
@property def browser_session(self): """Return a ``requests.Session`` instance for this session.""" if self._browser_session is None: self._browser_session = requests.Session() return self._browser_session @property def context(self): return self.context_stack.context @property def sess_stats(self): sess_stats = self.stats["sessions"][self.session_id] return sess_stats
[docs] def get_context(self, dotted_key=None, default=NO_DEFAULT): res = self.context_stack.get_attr(dotted_key) return res
[docs] def get_config(self, dotted_key=None, default=NO_DEFAULT): res = self.run_manager.config_manager.get(dotted_key, default) return res
[docs] def log_info(self, *args):, *args)
# self.publish("log", self.session_id, *args, level="info")
[docs] def has_errors(self, or_warnings=False): return self.sess_stats["errors"] > 0
[docs] def check_run_limits(self, seq_name): """Check if current time or number of errors exceeds the configured limits. Args: seq_name (str): current sequence name. Used to determine if a stopping session should still execute the 'end' sequence if the limit was reached during a main sequence. Returns: (bool) false if the current operation should be skipped. """ cs = self._cancelled_seq err_limit_reached = ( # Compare max_errors against global error count self.max_errors and self.stats.error_count() >= self.max_errors ) run_time = self.run_manager.get_run_time() time_limit_reached = self.max_time and run_time > self.max_time if not cs and (err_limit_reached or time_limit_reached): # We just hit a limit: issue a warning and take a note of the sequence self._cancelled_seq = seq_name # self.stats.stats["run_limit_reached"] = True if err_limit_reached: msg = "Reached max. error limit of {}: stopping...".format( self.max_errors ) elif time_limit_reached: msg = "Reached max. run time limit of {}: stopping...".format( self.max_time ) self.stats.report_limit_violation(msg) logger.warning(yellow(msg)) return False elif cs in ("init", "end"): # The limit was reached inside the init or end sequence: always skip return False elif cs: # The limit was reached inside a main sequence: allow to run the end # sequence but skip all others return seq_name == "end" return True
[docs] def report_activity_start(self, sequence, activity): """Called by session runner before activities is executed.""" path = self.context_stack.path() self.stats.report_start(self, sequence, activity, path=path)"{} {}".format("DRY-RUN" if self.dry_run else "Execute", path))
[docs] def report_activity_error(self, sequence, activity, activity_args, exc): """Called session runner when activity `execute()` or assertions raise an error.""" #"errors") if isinstance(exc, SkippedError): logger.warning(yellow("Skipped {}".format(activity))) self.pending_activity = None return # Create a copy of the current context, so we can shorten values context = self.context_stack.context.copy() context["last_result"] = shorten_string(context.get("last_result"), 500, 100) msg = [] # msg.append("{} {}: {!r}:".format(self.context_stack, activity, exc)) # msg.append("{!r}:".format(exc)) msg.append("{!r}:".format(exc)) if isinstance(exc, ActivityAssertionError): msg.append("Failed assertions:") for err in exc.assertion_list: msg.append(" - {}".format(err)) msg.append("Execution path: {}".format(self.context_stack)) msg.append("Activity: {}".format(activity)) msg.append("Activity args: {}".format(activity_args)) msg.append("Context: {}".format(context)) msg = "\n ".join(msg) logger.error(red(msg)) self.stats.report_error(self, sequence, activity, error=msg) return
[docs] def report_activity_result(self, sequence, activity, activity_args, result, elap): """Called session runner when activity `execute()` completes.""" self.stats.report_end(self, sequence, activity)
[docs] def _process_activity_result(self, activity, activity_args, result, elap): """Perform common checks. Raises: ActivityAssertionError """ context = self.context_stack.context errors = [] # warnings = [] arg = float(activity_args.get("assert_max_time", 0)) if arg and elap > arg: errors.append( "Execution time limit of {} seconds exceeded: {:.3} sec.".format( arg, elap ) ) arg = activity_args.get("assert_match") if arg: text = str(result) # Note: use (not .match)! if not, text, re.MULTILINE): errors.append( "Result does not match `{}`: {!r}".format( arg, shorten_string(text, 500, 100) ) ) arg = activity_args.get("store_json") if arg: for var_name, key_path in arg.items(): try: val = get_dict_attr(result, key_path) context[var_name] = val except Exception: errors.append( "store_json could not find `{}` in activity result {!r}".format( key_path, result ) ) if errors: raise ActivityAssertionError(errors) return
[docs] def run_sequence(self, seq_name, sequence): stack = self.context_stack context = stack.context self.publish( "start_sequence", session=self, sequence=sequence, path=stack, ) self.stats.report_start(self, seq_name, None) start_sequence = time.monotonic() for act_idx, activity_args in enumerate(sequence, 1): # activity_args["activity"] is an instance of ActivityBase that # we want to re-use it for every session. # The rest of activity_args is copied, so session data is separated activity = activity_args["activity"] activity_args = deepcopy(activity_args) activity_args.pop("activity") # Add activity info to path # Note: `get_info()` is not as detailed as it could, since we don't # pass the expanded args here. We set it anyway, so we have a valid # stack in case `_evaluate_macros()` blows. with stack.enter( "#{:02}-{}".format(act_idx, activity.get_info(session=self)) ): expanded_args = self._evaluate_macros(activity_args, context) # Let activity do internal calculations, that might be used by # the follwing call to `get_info()` activity.prepare_execute(self, expanded_args) # Enhance the path info with expanded args stack.set_last_part( activity.get_info(expanded_args=expanded_args, session=self) ) error = None result = None self.publish( "start_activity", session=self, sequence=sequence, activity=activity, expanded_args=expanded_args, context=context, path=stack, ) start_activity = time.monotonic() self.report_activity_start(seq_name, activity) try: if self.stop_request.is_set(): raise StoppedError if not self.check_run_limits(seq_name): raise SkippedError result = activity.execute(self, **expanded_args) context["last_result"] = result # Evaluate standard `assert_...` and `store_...` clauses: elap = time.monotonic() - start_activity self._process_activity_result( activity, activity_args, result, elap, ) self.report_activity_result( seq_name, activity, activity_args, result, elap, ) except (Exception, KeyboardInterrupt) as e: if isinstance(e, KeyboardInterrupt): self.stop_request.set() error = e self.report_activity_error(seq_name, activity, activity_args, e) if not isinstance(e, (KeyboardInterrupt, StressorError)): logger.exception("") # return False finally: elap = time.monotonic() - start_activity self.publish( "end_activity", session=self, sequence=sequence, path=stack, activity=activity, result=result, error=error, elap=elap, context=context, ) elap = time.monotonic() - start_sequence self.stats.report_end(self, seq_name, None) self.publish( "end_sequence", session=self, sequence=sequence, path=stack, elap=elap, ) context["last_result"] = None return not self.has_errors()
[docs] def run(self): stack = self.context_stack rm = self.run_manager config_manager = rm.config_manager config = config_manager.config sequences = config_manager.sequences scenario = config_manager.scenario sessions = config_manager.sessions session_duration = float(sessions.get("duration", 0.0)) self.publish("start_session", session=self) self.stats.report_start(self, None, None) start_session = time.monotonic() skip_all = False skip_all_but_end = False for seq_idx, seq_def in enumerate(scenario, 1): seq_name = seq_def["sequence"] if skip_all or (skip_all_but_end and seq_name != "end"): logger.warning("Skipping sequence '{}'.".format(seq_name)) continue sequence = sequences.get(seq_name) loop_repeat = int(seq_def.get("repeat", 0)) loop_duration = float(seq_def.get("duration", 0.0)) start_seq_loop = time.monotonic() loop_idx = 0 while True: loop_idx += 1 if not self.check_run_limits(seq_name=seq_name): skip_all_but_end = True break # One single pass by default if not loop_repeat and not loop_duration and loop_idx > 1: break # `Sequence repeat: COUNT`: if loop_repeat and loop_idx > loop_repeat: break # `--single`: if loop_idx > 1 and config.get("force_single"): logger.warning( "force_single: sequence '{}' skipping remaining {} loops.".format( seq_name, loop_repeat - 1 if loop_repeat else "" ) ) break now = time.monotonic() # `Sequence duration: SECS`: if loop_duration > 0 and now > (start_seq_loop + loop_duration): "Stopping sequence '{}' loop after {} sec.".format( seq_name, loop_duration ) ) break # `Session duration: SECS` (but run 'end' sequence): elif ( seq_name != "end" and session_duration > 0 and now > (start_session + session_duration) ): "Stopping scenario '{}' loop after {} sec.".format( seq_name, session_duration ) ) skip_all_but_end = True break with stack.enter("#{:02}-{}@{}".format(seq_idx, seq_name, loop_idx)): is_ok = self.run_sequence(seq_name, sequence) if seq_name == "init" and not is_ok: logger.error( "Stopping scenario due to an error in the 'init' sequence." ) skip_all = True break elif self.stop_request.is_set(): logger.error("Stopping scenario due to a stop request.") # TODO: a second 'ctrl-c' should not be so graceful skip_all_but_end = True break # self.stats.report_end(self, seq_name, None) elap = time.monotonic() - start_session self.stats.report_end(self, None, None) self.publish("end_session", session=self, elap=elap) # if self._cancelled_seq: # return False return not self.has_errors()