from __future__ import annotations
import csv
import logging
import os.path
from functools import wraps
from html import escape
from io import StringIO
from json import dumps
from itertools import chain
from time import time
from typing import TYPE_CHECKING, Optional, Any, Dict, List
import gevent
from flask import Flask, make_response, jsonify, render_template, request, send_file, Response
from flask_basicauth import BasicAuth
from gevent import pywsgi
from .exception import AuthCredentialsError
from .runners import MasterRunner, STATE_RUNNING, STATE_MISSING
from .log import greenlet_exception_logger
from .stats import StatsCSVFileWriter, StatsErrorDict, sort_stats
from . import stats as stats_module, __version__ as version, argument_parser
from .stats import StatsCSV
from .user.inspectuser import get_ratio
from .util.cache import memoize
from .util.rounding import proper_round
from .util.timespan import parse_timespan
from .html import get_html_report
from flask_cors import CORS
if TYPE_CHECKING:
from .env import Environment
logger = logging.getLogger(__name__)
greenlet_exception_handler = greenlet_exception_logger(logger)
DEFAULT_CACHE_TIME = 2.0
[docs]class WebUI:
"""
Sets up and runs a Flask web app that can start and stop load tests using the
:attr:`environment.runner <locust.env.Environment.runner>` as well as show the load test statistics
in :attr:`environment.stats <locust.env.Environment.stats>`
"""
app: Optional[Flask] = None
"""
Reference to the :class:`flask.Flask` app. Can be used to add additional web routes and customize
the Flask app in other various ways. Example::
from flask import request
@web_ui.app.route("/my_custom_route")
def my_custom_route():
return "your IP is: %s" % request.remote_addr
"""
greenlet: Optional[gevent.Greenlet] = None
"""
Greenlet of the running web server
"""
server: Optional[pywsgi.WSGIServer] = None
"""Reference to the :class:`pyqsgi.WSGIServer` instance"""
template_args: Dict[str, Any]
"""Arguments used to render index.html for the web UI. Must be used with custom templates
extending index.html."""
def __init__(
self,
environment: "Environment",
host: str,
port: int,
auth_credentials: Optional[str] = None,
tls_cert: Optional[str] = None,
tls_key: Optional[str] = None,
stats_csv_writer: Optional[StatsCSV] = None,
delayed_start=False,
userclass_picker_is_active=False,
):
"""
Create WebUI instance and start running the web server in a separate greenlet (self.greenlet)
Arguments:
environment: Reference to the current Locust Environment
host: Host/interface that the web server should accept connections to
port: Port that the web server should listen to
auth_credentials: If provided, it will enable basic auth with all the routes protected by default.
Should be supplied in the format: "user:pass".
tls_cert: A path to a TLS certificate
tls_key: A path to a TLS private key
delayed_start: Whether or not to delay starting web UI until `start()` is called. Delaying web UI start
allows for adding Flask routes or Blueprints before accepting requests, avoiding errors.
"""
environment.web_ui = self
self.stats_csv_writer = stats_csv_writer or StatsCSV(environment, stats_module.PERCENTILES_TO_REPORT)
self.environment = environment
self.host = host
self.port = port
self.tls_cert = tls_cert
self.tls_key = tls_key
self.userclass_picker_is_active = userclass_picker_is_active
app = Flask(__name__)
CORS(app)
self.app = app
app.jinja_env.add_extension("jinja2.ext.do")
app.debug = True
app.root_path = os.path.dirname(os.path.abspath(__file__))
self.app.config["BASIC_AUTH_ENABLED"] = False
self.auth: Optional[BasicAuth] = None
self.greenlet: Optional[gevent.Greenlet] = None
self._swarm_greenlet: Optional[gevent.Greenlet] = None
self.template_args = {}
if auth_credentials is not None:
credentials = auth_credentials.split(":")
if len(credentials) == 2:
self.app.config["BASIC_AUTH_USERNAME"] = credentials[0]
self.app.config["BASIC_AUTH_PASSWORD"] = credentials[1]
self.app.config["BASIC_AUTH_ENABLED"] = True
self.auth = BasicAuth()
self.auth.init_app(self.app)
else:
raise AuthCredentialsError(
"Invalid auth_credentials. It should be a string in the following format: 'user:pass'"
)
if environment.runner:
self.update_template_args()
if not delayed_start:
self.start()
@app.route("/")
@self.auth_required_if_enabled
def index() -> str | Response:
if not environment.runner:
return make_response("Error: Locust Environment does not have any runner", 500)
self.update_template_args()
return render_template("index.html", **self.template_args)
@app.route("/swarm", methods=["POST"])
@self.auth_required_if_enabled
def swarm() -> Response:
assert request.method == "POST"
# Loading UserClasses & ShapeClasses if Locust is running with UserClass Picker
if self.userclass_picker_is_active:
if not self.environment.available_user_classes:
err_msg = "UserClass picker is active but there are no available UserClasses"
return jsonify({"success": False, "message": err_msg, "host": environment.host})
# Getting Specified User Classes
form_data_user_class_names = request.form.getlist("user_classes")
# Updating UserClasses
if form_data_user_class_names:
user_classes = {}
for user_class_name, user_class_object in self.environment.available_user_classes.items():
if user_class_name in form_data_user_class_names:
user_classes[user_class_name] = user_class_object
else:
if self.environment.runner and self.environment.runner.state == STATE_RUNNING:
# Test is already running
# Using the user classes that have already been selected
user_classes = {
key: value
for (key, value) in self.environment.available_user_classes.items()
if value in self.environment.user_classes
}
else:
# Starting test with no user class selection
# Defaulting to using all available user classes
user_classes = self.environment.available_user_classes
self._update_user_classes(user_classes)
# Updating ShapeClass if specified in WebUI Form
form_data_shape_class_name = request.form.get("shape_class", "Default")
if form_data_shape_class_name == "Default":
self._update_shape_class(None)
else:
self._update_shape_class(form_data_shape_class_name)
parsed_options_dict = vars(environment.parsed_options) if environment.parsed_options else {}
run_time = None
for key, value in request.form.items():
if key == "user_count": # if we just renamed this field to "users" we wouldn't need this
user_count = int(value)
elif key == "spawn_rate":
spawn_rate = float(value)
elif key == "host":
# Replace < > to guard against XSS
environment.host = str(request.form["host"]).replace("<", "").replace(">", "")
elif key == "user_classes":
# Set environment.parsed_options.user_classes to the selected user_classes
parsed_options_dict[key] = request.form.getlist("user_classes")
elif key == "run_time":
if not value:
continue
try:
run_time = parse_timespan(value)
except ValueError:
err_msg = "Valid run_time formats are : 20, 20s, 3m, 2h, 1h20m, 3h30m10s, etc."
logger.error(err_msg)
return jsonify({"success": False, "message": err_msg, "host": environment.host})
elif key in parsed_options_dict:
# update the value in environment.parsed_options, but dont change the type.
# This won't work for parameters that are None
parsed_options_dict[key] = type(parsed_options_dict[key])(value)
if environment.shape_class and environment.runner is not None:
environment.runner.start_shape()
return jsonify(
{"success": True, "message": "Swarming started using shape class", "host": environment.host}
)
if self._swarm_greenlet is not None:
self._swarm_greenlet.kill(block=True)
self._swarm_greenlet = None
if environment.runner is not None:
self._swarm_greenlet = gevent.spawn(environment.runner.start, user_count, spawn_rate)
self._swarm_greenlet.link_exception(greenlet_exception_handler)
response_data = {
"success": True,
"message": "Swarming started",
"host": environment.host,
}
if run_time:
gevent.spawn_later(run_time, self._stop_runners).link_exception(greenlet_exception_handler)
response_data["run_time"] = run_time
if self.userclass_picker_is_active:
response_data["user_classes"] = sorted(user_classes.keys())
return jsonify(response_data)
else:
return jsonify({"success": False, "message": "No runner", "host": environment.host})
@app.route("/stop")
@self.auth_required_if_enabled
def stop() -> Response:
if self._swarm_greenlet is not None:
self._swarm_greenlet.kill(block=True)
self._swarm_greenlet = None
if environment.runner is not None:
environment.runner.stop()
return jsonify({"success": True, "message": "Test stopped"})
@app.route("/stats/reset")
@self.auth_required_if_enabled
def reset_stats() -> str:
environment.events.reset_stats.fire()
if environment.runner is not None:
environment.runner.stats.reset_all()
environment.runner.exceptions = {}
return "ok"
@app.route("/stats/report")
@self.auth_required_if_enabled
def stats_report() -> Response:
res = get_html_report(self.environment, show_download_link=not request.args.get("download"))
if request.args.get("download"):
res = app.make_response(res)
res.headers["Content-Disposition"] = f"attachment;filename=report_{time()}.html"
return res
def _download_csv_suggest_file_name(suggest_filename_prefix: str) -> str:
"""Generate csv file download attachment filename suggestion.
Arguments:
suggest_filename_prefix: Prefix of the filename to suggest for saving the download. Will be appended with timestamp.
"""
return f"{suggest_filename_prefix}_{time()}.csv"
def _download_csv_response(csv_data: str, filename_prefix: str) -> Response:
"""Generate csv file download response with 'csv_data'.
Arguments:
csv_data: CSV header and data rows.
filename_prefix: Prefix of the filename to suggest for saving the download. Will be appended with timestamp.
"""
response = make_response(csv_data)
response.headers["Content-type"] = "text/csv"
response.headers[
"Content-disposition"
] = f"attachment;filename={_download_csv_suggest_file_name(filename_prefix)}"
return response
@app.route("/stats/requests/csv")
@self.auth_required_if_enabled
def request_stats_csv() -> Response:
data = StringIO()
writer = csv.writer(data)
self.stats_csv_writer.requests_csv(writer)
return _download_csv_response(data.getvalue(), "requests")
@app.route("/stats/requests_full_history/csv")
@self.auth_required_if_enabled
def request_stats_full_history_csv() -> Response:
options = self.environment.parsed_options
if options and options.stats_history_enabled and isinstance(self.stats_csv_writer, StatsCSVFileWriter):
return send_file(
os.path.abspath(self.stats_csv_writer.stats_history_file_name()),
mimetype="text/csv",
as_attachment=True,
download_name=_download_csv_suggest_file_name("requests_full_history"),
etag=True,
max_age=0,
conditional=True,
last_modified=None,
)
return make_response("Error: Server was not started with option to generate full history.", 404)
@app.route("/stats/failures/csv")
@self.auth_required_if_enabled
def failures_stats_csv() -> Response:
data = StringIO()
writer = csv.writer(data)
self.stats_csv_writer.failures_csv(writer)
return _download_csv_response(data.getvalue(), "failures")
@app.route("/stats/requests")
@self.auth_required_if_enabled
@memoize(timeout=DEFAULT_CACHE_TIME, dynamic_timeout=True)
def request_stats() -> Response:
stats: List[Dict[str, Any]] = []
errors: List[StatsErrorDict] = []
if environment.runner is None:
report = {
"stats": stats,
"errors": errors,
"total_rps": 0.0,
"fail_ratio": 0.0,
"current_response_time_percentile_1": None,
"current_response_time_percentile_2": None,
"state": STATE_MISSING,
"user_count": 0,
}
if isinstance(environment.runner, MasterRunner):
report.update({"workers": []})
return jsonify(report)
for s in chain(sort_stats(environment.runner.stats.entries), [environment.runner.stats.total]):
stats.append(
{
"method": s.method,
"name": s.name,
"safe_name": escape(s.name, quote=False),
"num_requests": s.num_requests,
"num_failures": s.num_failures,
"avg_response_time": s.avg_response_time,
"min_response_time": 0 if s.min_response_time is None else proper_round(s.min_response_time),
"max_response_time": proper_round(s.max_response_time),
"current_rps": s.current_rps,
"current_fail_per_sec": s.current_fail_per_sec,
"median_response_time": s.median_response_time,
"ninetieth_response_time": s.get_response_time_percentile(0.9),
"ninety_ninth_response_time": s.get_response_time_percentile(0.99),
"avg_content_length": s.avg_content_length,
}
)
for e in environment.runner.errors.values():
err_dict = e.serialize()
err_dict["name"] = escape(err_dict["name"])
err_dict["error"] = escape(err_dict["error"])
errors.append(err_dict)
# Truncate the total number of stats and errors displayed since a large number of rows will cause the app
# to render extremely slowly. Aggregate stats should be preserved.
truncated_stats = stats[:500]
if len(stats) > 500:
truncated_stats += [stats[-1]]
report = {"stats": truncated_stats, "errors": errors[:500]}
if stats:
report["total_rps"] = stats[len(stats) - 1]["current_rps"]
report["fail_ratio"] = environment.runner.stats.total.fail_ratio
report[
"current_response_time_percentile_1"
] = environment.runner.stats.total.get_current_response_time_percentile(
stats_module.PERCENTILES_TO_CHART[0]
)
report[
"current_response_time_percentile_2"
] = environment.runner.stats.total.get_current_response_time_percentile(
stats_module.PERCENTILES_TO_CHART[1]
)
if isinstance(environment.runner, MasterRunner):
workers = []
for worker in environment.runner.clients.values():
workers.append(
{
"id": worker.id,
"state": worker.state,
"user_count": worker.user_count,
"cpu_usage": worker.cpu_usage,
"memory_usage": worker.memory_usage,
}
)
report["workers"] = workers
report["state"] = environment.runner.state
report["user_count"] = environment.runner.user_count
return jsonify(report)
@app.route("/exceptions")
@self.auth_required_if_enabled
def exceptions() -> Response:
return jsonify(
{
"exceptions": [
{
"count": row["count"],
"msg": escape(row["msg"]),
"traceback": escape(row["traceback"]),
"nodes": ", ".join(row["nodes"]),
}
for row in (environment.runner.exceptions.values() if environment.runner is not None else [])
]
}
)
@app.route("/exceptions/csv")
@self.auth_required_if_enabled
def exceptions_csv() -> Response:
data = StringIO()
writer = csv.writer(data)
self.stats_csv_writer.exceptions_csv(writer)
return _download_csv_response(data.getvalue(), "exceptions")
@app.route("/tasks")
@self.auth_required_if_enabled
def tasks() -> Dict[str, Dict[str, Dict[str, float]]]:
runner = self.environment.runner
user_spawned: Dict[str, int]
if runner is None:
user_spawned = {}
else:
user_spawned = (
runner.reported_user_classes_count
if isinstance(runner, MasterRunner)
else runner.user_classes_count
)
task_data = {
"per_class": get_ratio(self.environment.user_classes, user_spawned, False),
"total": get_ratio(self.environment.user_classes, user_spawned, True),
}
return task_data
def start(self):
self.greenlet = gevent.spawn(self.start_server)
self.greenlet.link_exception(greenlet_exception_handler)
def start_server(self):
if self.tls_cert and self.tls_key:
self.server = pywsgi.WSGIServer(
(self.host, self.port), self.app, log=None, keyfile=self.tls_key, certfile=self.tls_cert
)
else:
self.server = pywsgi.WSGIServer((self.host, self.port), self.app, log=None)
self.server.serve_forever()
[docs] def stop(self):
"""
Stop the running web server
"""
self.server.stop()
[docs] def auth_required_if_enabled(self, view_func):
"""
Decorator that can be used on custom route methods that will turn on Basic Auth
authentication if the ``--web-auth`` flag is used. Example::
@web_ui.app.route("/my_custom_route")
@web_ui.auth_required_if_enabled
def my_custom_route():
return "custom response"
"""
@wraps(view_func)
def wrapper(*args, **kwargs):
if self.app.config["BASIC_AUTH_ENABLED"]:
if self.auth.authenticate():
return view_func(*args, **kwargs)
else:
return self.auth.challenge()
else:
return view_func(*args, **kwargs)
return wrapper
def update_template_args(self):
override_host_warning = False
if self.environment.host:
host = self.environment.host
elif self.environment.runner.user_classes:
all_hosts = {l.host for l in self.environment.runner.user_classes}
if len(all_hosts) == 1:
host = list(all_hosts)[0]
else:
# since we have multiple User classes with different host attributes, we'll
# inform that specifying host will override the host for all User classes
override_host_warning = True
host = None
else:
host = None
options = self.environment.parsed_options
is_distributed = isinstance(self.environment.runner, MasterRunner)
if is_distributed:
worker_count = self.environment.runner.worker_count
else:
worker_count = 0
stats = self.environment.runner.stats
extra_options = argument_parser.ui_extra_args_dict()
available_user_classes = (
None if not self.environment.available_user_classes else sorted(self.environment.available_user_classes)
)
available_shape_classes = ["Default"]
if self.environment.available_shape_classes:
available_shape_classes += sorted(self.environment.available_shape_classes.keys())
self.template_args = {
"locustfile": self.environment.locustfile,
"state": self.environment.runner.state,
"is_distributed": is_distributed,
"user_count": self.environment.runner.user_count,
"version": version,
"host": host,
"history": stats.history if stats.num_requests > 0 else {},
"override_host_warning": override_host_warning,
"num_users": options and options.num_users,
"spawn_rate": options and options.spawn_rate,
"worker_count": worker_count,
"is_shape": self.environment.shape_class and not self.userclass_picker_is_active,
"stats_history_enabled": options and options.stats_history_enabled,
"tasks": dumps({}),
"extra_options": extra_options,
"show_userclass_picker": self.userclass_picker_is_active,
"available_user_classes": available_user_classes,
"available_shape_classes": available_shape_classes,
"percentile1": stats_module.PERCENTILES_TO_CHART[0],
"percentile2": stats_module.PERCENTILES_TO_CHART[1],
}
def _update_shape_class(self, shape_class_name):
if shape_class_name:
shape_class = self.environment.available_shape_classes[shape_class_name]
else:
shape_class = None
# Validating ShapeClass
self.environment.shape_class = shape_class
self.environment._validate_shape_class_instance()
def _update_user_classes(self, user_classes):
self.environment.user_classes = list(user_classes.values())
# populate the locustfile which used in web ui title only
if self.environment.locustfile is None:
self.environment.locustfile = ",".join(self.environment.user_classes_by_name.keys())
# Validating UserClasses
self.environment._remove_user_classes_with_weight_zero()
self.environment._validate_user_class_name_uniqueness()
def _stop_runners(self):
self.environment.runner.stop()