apptainer build
Build an Apptainer image
Synopsis
IMAGE PATH:
When Apptainer builds the container, output can be one of a few formats:
default: The compressed Apptainer read only image format (default) sandbox: This is a read-write container within a directory structure
note: It is a common workflow to use the “sandbox” mode for development of the container, and then build it as a default Apptainer image for production use. The default format is immutable.
BUILD SPEC:
The build spec target is a definition (def) file, local image, or URI that can be used to create an Apptainer container. Several different local target formats exist:
def file : This is a recipe for building a container (examples below) directory: A directory structure containing a (ch)root file system image: A local image on your machine (will convert to sif if
it is legacy format)
Targets can also be remote and defined by a URI of the following formats:
library:// an image library (no default) docker:// a Docker/OCI registry (default Docker Hub) shub:// an Apptainer registry (default Singularity Hub) oras:// an OCI registry that holds SIF files using ORAS
Temporary files:
The location used for temporary directories defaults to ‘/tmp’ but can be overridden by the TMPDIR environment variable, and that can be overridden by the APPTAINER_TMPDIR environment variable. The temporary directory used during a build must be on a filesystem that has enough space to hold the entire container image, uncompressed, including any temporary files that are created and later removed during the build. You may need to set APPTAINER_TMPDIR or TMPDIR when building a large container on a system that has a small /tmp filesystem.
apptainer build [local options...] <IMAGE PATH> <BUILD SPEC>
Examples
DEF FILE BASE OS:
Library:
Bootstrap: library
From: debian:9
Docker:
Bootstrap: docker
From: tensorflow/tensorflow:latest
IncludeCmd: yes # Use the CMD as runscript instead of ENTRYPOINT
Singularity Hub:
Bootstrap: shub
From: singularityhub/centos
YUM/RHEL:
Bootstrap: yum
OSVersion: 7
MirrorURL: http://mirror.centos.org/centos-%{OSVERSION}/%{OSVERSION}/os/x86_64/
Include: yum
SUSE:
Bootstrap: zypper # on SLE system registration of build host is used
Include: zypper
openSUSE:
Bootstrap: zypper
MirrorURL: http://download.opensuse.org/distribution/openSUSE-stable/repo/oss
Include: zypper
Debian/Ubuntu:
Bootstrap: debootstrap
OSVersion: trusty
MirrorURL: http://us.archive.ubuntu.com/ubuntu/
Local Image:
Bootstrap: localimage
From: /home/dave/starter.img
Scratch:
Bootstrap: scratch # Populate the container with a minimal rootfs in %setup
DEFFILE SECTIONS:
The following sections are presented in the order of processing, with the exception
that labels and environment can also be manipulated in %post.
%pre
echo "This is a scriptlet that will be executed on the host, as root before"
echo "the container has been bootstrapped. This section is not commonly used."
%setup
echo "This is a scriptlet that will be executed on the host, as root, after"
echo "the container has been bootstrapped. To install things into the container"
echo "reference the file system location with $APPTAINER_ROOTFS."
%files
/path/on/host/file.txt /path/on/container/file.txt
relative_file.txt /path/on/container/relative_file.txt
%post
echo "This scriptlet section will be executed from within the container after"
echo "the bootstrap/base has been created and setup."
%environment
LUKE=goodguy
VADER=badguy
HAN=someguy
export HAN VADER LUKE
%test
echo "Define any test commands that should be executed after container has been"
echo "built. This scriptlet will be executed from within the running container"
echo "as the root user. Pay attention to the exit/return value of this scriptlet"
echo "as any non-zero exit code will be assumed as failure."
exit 0
%runscript
echo "Define actions for the container to be executed with the run command or"
echo "when container is executed."
%startscript
echo "Define actions for container to perform when started as an instance."
%labels
HELLO MOTO
KEY VALUE
%help
This is a text file to be displayed with the run-help command.
COMMANDS:
Build a sif file from an Apptainer recipe file:
$ apptainer build /tmp/debian0.sif /path/to/debian.def
Build a sif image from the Library:
$ apptainer build /tmp/debian1.sif library://debian:latest
Build a base sandbox from DockerHub, make changes to it, then build sif
$ apptainer build --sandbox /tmp/debian docker://debian:latest
$ apptainer exec --writable /tmp/debian apt-get install python
$ apptainer build /tmp/debian2.sif /tmp/debian
Options
-B, --bind stringArray a user-bind path specification. spec has the format src[:dest[:opts]],where src and dest are outside and inside paths. If dest is not given,it is set equal to src. Mount options ('opts') may be specified as 'ro'(read-only) or 'rw' (read/write, which is the default).Multiple bind paths can be given by a comma separated list.
--build-arg strings defines variable=value to replace {{ variable }} entries in build definition file
--build-arg-file string specifies a file containing variable=value lines to replace '{{ variable }}' with value in build definition files
--disable-cache do not use cache or create cache
--docker-host string specify a custom Docker daemon host
--docker-login login to a Docker Repository interactively
-e, --encrypt build an image with an encrypted file system
-f, --fakeroot build with the appearance of running as root (default when building from a definition file unprivileged)
--fix-perms ensure owner has rwX permissions on all container content for oci/docker sources
-F, --force overwrite an image file if it exists
-h, --help help for build
--json interpret build definition as JSON
--library string container Library URL
--mount stringArray a mount specification e.g. 'type=bind,source=/opt,destination=/hostopt'.
--no-cleanup do NOT clean up bundle after failed build, can be helpful for debugging
--no-https use http instead of https for docker:// oras:// and library://<hostname>/... URIs
-T, --notest build without running tests in %test section
--nv inject host Nvidia libraries during build for post and test sections
--nvccli use nvidia-container-cli for GPU setup (experimental)
--passphrase prompt for an encryption passphrase
--pem-path string enter an path to a PEM formatted RSA key for an encrypted container
--rocm inject host Rocm libraries during build for post and test sections
-s, --sandbox build image as sandbox format (chroot directory structure)
--section strings only run specific section(s) of deffile (setup, post, files, environment, test, labels, none) (default [all])
-u, --update run definition over existing container (skips header)
--userns build without using setuid even if available
--warn-unused-build-args shows warning instead of fatal message when build args are not exact matched
--writable-tmpfs during the %test section, makes the file system accessible as read-write with non persistent data (with overlay support only)