Stuck on an issue?

Lightrun Answers was designed to reduce the constant googling that comes with debugging 3rd party libraries. It collects links to all the places you might be looking at while hunting down a tough bug.

And, if you’re still stuck at the end, we’re happy to hop on a call to see how we can help out.

Docker run Could not find any locustfile! Ensure file ends in '.py'

See original GitHub issue

Describe the bug

I followed the instructions on https://docs.locust.io/en/stable/running-locust-docker.html to try to run the docker image

docker run -p 8089:8089 -v $PWD:/mnt/locust locustio/locust -f /mnt/locust/locustfile.py

but received this error " Could not find any locustfile! Ensure file ends in ‘.py’".

Here is my locustfile.py in $PWD:

import time
from locust import HttpUser, task, between

class QuickstartUser(HttpUser):
    wait_time = between(1, 2)
    @task
    def index_page(self):
        self.client.get("/")

This file works fine with locust running on my local machine (Ubuntu WSL of Windows 10), i.e. not using the container. I confirm the environment variable $PWD is present and pointing to my present working directory where my locustfile.py resides.

Expected behavior

The Docker run above should start Locust server and make its UI accessible on http://localhost:8089.

Actual behavior

$ docker run -p 8089:8089 -v $PWD:/mnt/locust locustio/locust -f /mnt/locust/locusttest1.py Could not find any locustfile! Ensure file ends in '.py' and see --help for available options. Surprisingly the above (default to latest tag) shows version 1.1. So I also tried v 1.3.1 but got the same error. $ docker run -p 8089:8089 -v $PWD:/mnt/locust locustio/locust:1.3.1 -f /mnt/locust/locusttest1.py Could not find any locustfile! Ensure file ends in '.py' and see --help for available options.

Steps to reproduce

copy my locustfile.py contents into a new file named locustfile.py in your working directory
run $ docker run -p 8089:8089 -v $PWD:/mnt/locust locustio/locust -f /mnt/locust/locusttest1.py

Environment

OS: Ubuntu 16.04 WSL of Windows 10
Python version: irrelevant because I am running the docker image
Locust version: 1.1 as shown by docker run -p 8089:8089 -v $PWD:/mnt/locust locustio/locust --version
Locust command line that you ran: see above docker run ...
Locust file contents (anonymized if necessary): see above