Using Locust as a library¶
It’s possible to use Locust as a library, instead of running Locust using the locust
command.
To run Locust as a library you need to create an Environment
instance:
from locust.env import Environment
env = Environment(user_classes=[MyTestUser])
The Environment
instance’s
create_local_runner
,
create_master_runner
or
create_worker_runner
can then be used to start a
Runner
instance, which can be used to start a load test:
env.create_local_runner()
env.runner.start(5000, spawn_rate=20)
env.runner.greenlet.join()
We could also use the Environment
instance’s
create_web_ui
method to start a Web UI that can be used
to view the stats, and to control the runner (e.g. start and stop load tests):
env.create_local_runner()
env.create_web_ui()
env.web_ui.greenlet.join()
Full example¶
import gevent
from locust import HttpUser, task, between
from locust.env import Environment
from locust.stats import stats_printer, stats_history
from locust.log import setup_logging
setup_logging("INFO", None)
class User(HttpUser):
wait_time = between(1, 3)
host = "https://docs.locust.io"
@task
def my_task(self):
self.client.get("/")
@task
def task_404(self):
self.client.get("/non-existing-path")
# setup Environment and Runner
env = Environment(user_classes=[User])
env.create_local_runner()
# start a WebUI instance
env.create_web_ui("127.0.0.1", 8089)
# start a greenlet that periodically outputs the current stats
gevent.spawn(stats_printer(env.stats))
# start a greenlet that save current stats to history
gevent.spawn(stats_history, env.runner)
# start the test
env.runner.start(1, spawn_rate=10)
# in 60 seconds stop the runner
gevent.spawn_later(60, lambda: env.runner.quit())
# wait for the greenlets
env.runner.greenlet.join()
# stop the web server for good measures
env.web_ui.stop()