---
title: Sarus
description: Run Nextflow pipeline tasks in Sarus containers converted from Docker images.
---

# Sarus

[Sarus](https://sarus.readthedocs.io) is a container runtime that converts Docker images to a common format for distribution and launch on high-performance computing (HPC) systems. With Sarus, you select an image from [Docker Hub](https://hub.docker.com/) and submit jobs that run entirely within the container.

## Prerequisites

Sarus must be installed in your execution environment.

## Images

Sarus converts a Docker image to Squashfs layers that are distributed and launched in the cluster. To build Sarus images, see the [Sarus documentation](https://sarus.readthedocs.io/en/stable/user/user_guide.html#develop-the-docker-image).

## How it works

Enable Sarus in the Nextflow configuration file:

```groovy
sarus.enabled = true
process.container = 'dockerhub_user/image_name:image_tag'
```

Sarus always searches the Docker Hub registry for images. If you do not specify an image tag, Sarus fetches the `latest` tag.

## Advanced settings

See the [`sarus`][config-sarus] configuration scope for advanced Sarus settings.

[config-sarus]: ../reference/config/sarus
