Running Locust with Docker

To keep things simple we provide a single Docker image that can run standalone, as a master, or as a slave.

Environment Variables

  • LOCUST_MODE

One of ‘standalone’, ‘master’, or ‘slave’. Defaults to ‘standalone’.

  • LOCUSTFILE_PATH

The path inside the container to the locustfile. Defaults to ‘/locustfile.py`

  • LOCUST_MASTER_HOST

The hostname of the master.

  • LOCUST_MASTER_PORT

The port used to communicate with the master. Defaults to 5557.

  • LOCUST_OPTS

Additional options to pass to locust. Defaults to ‘’.

Running your tests

The easiest way to get your tests running is to build an image with your test file built in. Once you’ve written your locustfile you can bake it into a Docker image with a simple Dockerfile:

` FROM locustio/locust ADD locustfile.py locustfile.py `

You’ll need to push the built image to a Docker repository such as Dockerhub, AWS ECR, or GCR in order for distributed infrastructure to be able to pull the image. See your chosen repository’s documentation on how to authenticate with the repository to pull the image.

For debugging locally you can run a container and pass your locustfile in as a volume:

` docker run -p 8089:8089 --volume $PWD/dir/of/locustfile:/mnt/locust -e LOCUSTFILE_PATH=/mnt/locust/locustfile.py -e TARGET_URL=https://abc.com locustio/locust `

To run in standalone mode without the web UI, you can use the LOCUST_OPTS environment variable to add the required options:

` docker run --volume $PWD/dir/of/locustfile:/mnt/locust -e LOCUSTFILE_PATH=/mnt/locust/locustfile.py -e TARGET_URL=https://abc.com -e LOCUST_OPTS="--clients=10 --no-web --run-time=600" locustio/locust `

If you are Kubernetes user, you can use the [Helm chart](https://github.com/helm/charts/tree/master/stable/locust) to scale and run locust.