Use build to download and assemble existing containers, convert containers from one format to another, or build a container from a Singularity recipe.


The build command accepts a target as input and produces a container as output. The target can be a Singularity Hub or Docker Hub URI, a path to an existing container, or a path to a Singularity Recipe file. The output container can be in squashfs, ext3, or directory format.

For a complete list of build options type singularity help build. For more info on building containers see Build a Container.


Download an existing container from Singularity Hub or Docker Hub

$ singularity build lolcow.simg shub://GodloveD/lolcow
$ singularity build lolcow.simg docker://godlovedc/lolcow

Create --writable images and --sandbox directories

$ sudo singularity build --writable lolcow.img shub://GodloveD/lolcow
$ sudo singularity build --sandbox lolcow/ shub://GodloveD/lolcow

Convert containers from one format to another

You can convert the three supported container formats using any combination.

$ sudo singularity build --writable development.img production.simg
$ singularity build --sandbox development/ production.simg
$ singularity build production2 development/

Build a container from a Singularity recipe

Given a Singularity Recipe called Singularity:

$ sudo singularity build lolcow.simg Singularity