Set up a compute node with Singularity

Note:

This page describes the requirements for a compute node in a Slurm or LSF cluster that will run containers dispatched by crunch-dispatch-slurm or arvados-dispatch-lsf. If you are installing a cloud cluster, refer to Build a cloud compute node image.

Note:

These instructions apply when Containers.RuntimeEngine is set to singularity, refer to Set up a compute node with Docker when running docker.

Introduction
Install python-arvados-fuse and crunch-run and squashfs-tools
Set up Singularity
Singularity mksquashfs configuration

Introduction

Please refer to the Singularity documentation in the Architecture section.

This page describes how to configure a compute node so that it can be used to run containers dispatched by Arvados on a static cluster. These steps must be performed on every compute node.

Install python-arvados-fuse and crunch-run and squashfs-tools

Red Hat and Centos

# yum install python-arvados-fuse crunch-run squashfs-tools

Debian and Ubuntu

# apt-get install python-arvados-fuse crunch-run squashfs-tools

Set up Singularity

Follow the Singularity installation instructions. Make sure singularity and mksquashfs are working:

$ singularity version
3.7.4
$ mksquashfs -version
mksquashfs version 4.3-git (2014/06/09)
[...]

Then update Containers.RuntimeEngine in your cluster configuration:

      # Container runtime: "docker" (default) or "singularity"
      RuntimeEngine: singularity

Singularity mksquashfs configuration

Docker images are converted on the fly by mksquashfs, which can consume a considerable amount of RAM. The RAM usage of mksquashfs can be restricted in /etc/singularity/singularity.conf with a line like mksquashfs mem = 256M. The amount of memory made available for mksquashfs should be configured lower than the smallest amount of memory requested by a container on the cluster to avoid the conversion being killed for using too much memory. The default memory allocation in CWL is 256M, so that is also a good choice for the mksquashfs mem setting.

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