Adjust wait_time in locust using custom arguments via CLI - locust

Question

I want to adjust wait_time parameter by passing it via CLI.
I have tried the following way:
custom_wait_time = None
# Add custom argument to locust
#events.init_command_line_parser.add_listener
def init_parser(parser):
parser.add_argument("--locust-wait-time",
type=int,
include_in_web_ui=True,
default=None,
help="Wait time per each request of a user.")
#events.init.add_listener
def _(environment, **kwargs):
global custom_wait_time
custom_wait_time = int(environment.parsed_options.locust_wait_time)
print(custom_wait_time) # First print
class MyUser(HttpUser):
global custom_wait_time
print(custom_wait_time) # Second print
wait_time = constant(custom_wait_time)
Assume that custom_wait_time=10 when I pass it via CLI, the First print gives me custom_wait_time=10 while the Second print gives me custom_wait_time=None instead of 10, so the wait_time = constant(custom_wait_time) will break and give me the error below:
Traceback (most recent call last):
File "src/gevent/greenlet.py", line 908, in gevent._gevent_cgreenlet.Greenlet.run
File "/Users/opt/anaconda3/envs/ai/lib/python3.7/site-packages/locust/user/users.py", line 176, in run_user
user.run()
File "/Users/opt/anaconda3/envs/ai/lib/python3.7/site-packages/locust/user/users.py", line 144, in run
self._taskset_instance.run()
File "/Users/opt/anaconda3/envs/ai/lib/python3.7/site-packages/locust/user/task.py", line 367, in run
self.wait()
File "/Users/opt/anaconda3/envs/ai/lib/python3.7/site-packages/locust/user/task.py", line 445, in wait
self._sleep(self.wait_time())
File "/Users/opt/anaconda3/envs/ai/lib/python3.7/site-packages/locust/user/task.py", line 451, in _sleep
gevent.sleep(seconds)
File "/Users/opt/anaconda3/envs/ai/lib/python3.7/site-packages/gevent/hub.py", line 157, in sleep
if seconds <= 0:
TypeError: '<=' not supported between instances of 'NoneType' and 'int'
Any help would be appreciated.

Answer 1

The problem is that the code will run in the wrong order - MyUser is defined before any of the init-methods are called.
If you instead do MyUser.wait_time = constant(custom_wait_time) inside your init handler (and dont set it at all in the class) it should work.
That way you dont need any globals either :)

Answer 2

I've just do the same work.
#events.init_command_line_parser.add_listener
def _(parser):
parser.add_argument("--waitTime", type=float, env_var="LOCUST_WAIT_TIME", default=1.0, help="wait time between each task of an user")
# Set `include_in_web_ui` to False if you want to hide from the web UI
#parser.add_argument("--my-ui-invisible-argument", include_in_web_ui=False, default="I am invisible")
and in the test class, just use it value like this
class GetInfoUser(HttpUser):
def wait_time(self):
return self.environment.parsed_options.waitTime