General Commands Manual (prm)

NAME¶

image-garden — construct and operate test virtual machines

SYNOPSIS¶

image-garden make [-n] [GOAL]

image-garden allocate [--premade] [--nice] SYSTEM.ARCH

image-garden discard ADDRESS

image-garden version

DESCRIPTION¶

image-garden downloads, initializes and optionally operates virtual machine images for popular operating systems. All the systems are designed for testing and come configured with well-known username and password, usually matching the name of the system.

Options recognized by image-garden make

-n: Display commands instead of executing them. This option is useful for learning how to make individual disk images.

Options recognized by image-garden allocate

--premade: Assume presence of pre-made disk images and do not re-generate them even if they are out-of-date. This option is useful for ensuring that CI/CD jobs do not re-build disk images even if timestamps would suggest they should.
--nice: Wrap execution of virtual machines with nice, so that it does not compete for CPU with other applications.

Make Goals¶

The image-garden make sub-command allows building one or more goals corresponding to virtual machine images and their support files.

The following goals are documented. Note that ARCH and SYSTEM are placeholders for CPU architecture as named by the Linux kernel and standardized distribution name, respectively. Please see the table for a complete list of valid SYSTEM-ARCH combinations.

help: Display help message specific to the set of make rules contained within image-garden
all: Build all of the images for the native CPU architecture.
fetch: Fetch all the base cloud images or installers, so that further work can be done mostly offline. The only exception is installation if packages described by per-project cloud-init profiles.
clean: Remove all the generated disk images from the current directory.
distclean: Remove all the base cloud images and installer images from the per-user cache directory.
$SYSTEM.$ARCH.qcow2: qemu disk image of operating system $SYSTEM for CPU architecture $ARCH. Cloud disks contain internal reference to base image stored in per-user cache directory. Both files are required at runtime.
$SYSTEM.$ARCH.qcow2.log: Serial console output collected during first boot of the machine.
$SYSTEM.$ARCH.run: Shell script for running the virtual machine. This script supports extensive customization through environment variables and command line arguments. Command line arguments are passed directly to image-garden qemu-system-$ARCH . Recognized environment variables are described in a dedicated section below.
$SYSTEM.$ARCH.efi-code.img: Symbolic link to efi-code.$ARCH.img.
$SYSTEM.$ARCH.efi-vars.img: Disk image with current state of the boot firmware corresponding to $SYSTEM.$ARCH.qcow2.
$SYSTEM.seed.iso: ISO 9660 disk image with cloud-init files used during first boot.
$SYSTEM.user-data: Text of the cloud-init user data. This file exists briefly as a prerequisite for $SYSTEM.seed.iso.
$SYSTEM.meta-data: Text of the cloud-init meta data. This file exists briefly as a prerequisite for $SYSTEM.seed.iso.
efi-code.aarch64.img: Disk image of EFI firmware for aarch64 CPU architecture.
efi-vars.aarch64.img: Disk image of with the unmodified state of EFI firmware for the aarch64 CPU architecture.
efi-code.x86_64.img: Disk image of EFI firmware for the x86_64 CPU architecture.
efi-vars.x86_64.img: Disk image of with the unmodified state of EFI firmware for the x86_64 CPU architecture.

System Names¶

Systems are identifiers for a particular operating system, variant, release and CPU architecture. The following list contains all the systems recognized by image-garden.

almalinux-cloud-{8,9}: Alma Linux cloud images.
alpine-cloud-3: Alpine Linux cloud image.
amazonliux-cloud-2023: Amazon Linux cloud image.
archlinux-cloud: Arch Linux cloud image. This system is only supported on the x86_64 CPU architecture.
centos-cloud-{9,10}: CentOS cloud images (usually CentOS stream).
debian-cloud-{10,11,12,13,sid}: Debian cloud images.
fedora-cloud-{38,39,40,41}: Fedora cloud images.
opensuse-cloud-{15.4,15.5,15.16,tumbleweed}: openSUSE cloud images.
oracle-cloud-{8,9}: Oracle Linux cloud images.
rocky-cloud-{8,9}: Rocky Linux cloud images.
ubuntu-cloud-14.04: This system fails to boot correctly.
ubuntu-cloud-{16,18,20,22,24}.04: Ubuntu Long Term Support (LTS) cloud images.
ubuntu-cloud-{24.10,25.04}: Ubuntu development releases cloud images.
ubuntu-core-{16,18,20,22,24}: Ubuntu Core images. Core 16 and 18 are only supported on the x86_64 CPU architecture.

FILES¶

.image-garden: Sub-directory containing all image, log and lock files. If this directory does not exist then all such files are placed in the directory where image-garden is invoked from.
.image-garden.mk: Makefile implicitly included by image-garden make. This file is designed for defining cloud-init user-data templates with project-specific build and test dependencies.
$HOME/.cache/image-garden/dl: Directory with downloaded, unmodified virtual machine images. The files are organized into sub-directories specific to each distribution. Inside symbolic links provide an unified naming scheme regardless of the naming scheme used by a particular distributor.

ENVIRONMENT¶

Environment variables are split into sections to indicate which of the sub-commands uses them.

Environment for image-garden make¶

XDG_CACHE_HOME: Directory with per-user cache files that may be safely deleted. According to the specification the default value is "$HOME/.cache".
GARDEN_CACHE_DIR: Directory with non-essential files that can be reused across projects. The default value is "$XDG_CACHE_HOME/image-garden".
GARDEN_DL_DIR: Directory where downloaded operating system images are stored. Those images may be sizable so care needs to be taken to avoid using excessive amount of disk space. All the images stored here are used in read-only mode and are automatically shared by different project developed by the same user. The default value is "$GARDEN_CACHE_DIR/dl".
QEMU_ENV_QUIRKS: A list of environment variables to set before invoking qemu. This was introduced to allow expressing that a given system cannot boot with virtio disk and needs to use SCSI disks instead.
QEMU_MEM_SIZE: Amount of memory, in megabytes, to provide to each virtual machine. This value is copied into the generated $SYSTEM.run scripts. The default value is "2048", for 2GB of runtime memory. Not to be confused with similarly-named QEMU_MEM_OPTION.
QEMU_IMG_SIZE: Size of the virtual disk image created by qemu-img(1) when invoked from image-garden. The default value is "64G". Note that images use a format with internal representation of sparse areas. The required disk space is much smaller than this size.
QEMU_SMP_X86_64: The number of virtual CPU cores for virtual machines emulating the x86_64 CPU architecture. The default value is "4" when the CPU architecture of the host and the guest are the same or "1" otherwise. Not to be confused with similarly-named QEMU_SMP_OPTION.
QEMU_SMP_AARCH64: The number of virtual CPU cores for virtual machines emulating the aarch64 CPU architecture. The default value is "4" when the CPU architecture of the host and the guest are the same or "1" otherwise. Not to be confused with similarly-named QEMU_SMP_OPTION.
QEMU_SYSTEM_X86_64: Full path of the qemu-system-x86_64 program to use instead of the one found on PATH.
QEMU_SYSTEM_AARCH64: Full path of the qemu-system-aarch64 program to use instead of the one found on PATH.
QEMU_IMG: Full path of the qemu-img program to use instead of the one found on PATH.
MKPASSWD: Full path of the mkpasswd program to use instead of the one found on PATH.
GENISOIMAGE: Full path of the genisoimage program to use instead of the one found on PATH.
WGET: Full path of the wget program to use instead of the one found on PATH.

Environment for image-garden allocate¶

XDG_RUNTIME_DIR: Directory with per-user runtime files that do not persist across reboots. According to the specification the default value is "/run/user/$UID". The image-garden program, when used as a back-end for the spread(1) test system uses this directory to keep track of running virtual machines and their TCP port numbers.
QEMU_SNAPSHOT_OPTION: Overrides the in-memory snapshot option. Set this to the empty string to allocate a machine that persists all changes on disk.

Environment for .run scripts.¶

The following environment variables are used by generated .run scripts.

QEMU_MEM_OPTION: Memory configuration options to pass to qemu. Example value is "-m 1024".
QEMU_SMP_OPTION: CPU topology options to pass to qemu. When unset the default value is "-smp $QEMU_SMP_$(uname -m)". Example value is "-smp $(nproc)".
QEMU_DISPLAY_OPTION: Graphical display options to pass to qemu. When unset the default value is "-nographic". Example value is "-display gtk".
QEMU_BOOT_FIRMWARE_OPTION: Boot firmware options to pass to qemu. The default value depends on the requirement of the booted system. For systems booting with EFI a pair of "-drive pflash" arguments is used for representing EFI code and EFI variables. For systems booting with legacy BIOS no options are provided.
QEMU_RNG_OPTION: Random-number configuration options to pass to qemu. When unset the default value is "-device virtio-rng-pci"
QEMU_NET_OPTION: Network configuration options to pass to qemu. When unset the default value is "-netdev user,id=netdev0${QEMU_NETDEV_USER_EXTRA:-} -device virtio-net-pci,netdev=netdev0,id=net0 -smbios type=41,designation=Virtual-LAN,instance=1,kind=ethernet,pcidev=net0"

EXAMPLES¶

To create a bootable image of cloud variant of Debian 13 (trixie) for x86_64 architecture run:

image-garden make debian-cloud-13.x86_64.run

To use image-garden together with spread(1) put the following snippet into your spread.yaml file. Note that using exec allows image-garden to automatically perform the equivalent of calling spread shell functions ADDRESS, FATAL or ERROR.

backends:
  garden:
    type: adhoc
    allocate: exec image-garden allocate "$SPREAD_SYSTEM"."$(uname -m)"
    discard: exec image-garden discard "$SPREAD_SYSTEM_ADDRESS"
    systems:
      - debian-cloud-13:
          username: debian
          password: debian

To customize the virtual machine to a particular project create a .image-garden.mk file in the root of the project and define one or more cloud-init user-data templates which contain list of packages to install or commands to run. Make sure to include the default template that is essential for image-garden operation. You can assume that the default template ends with a section that runs one or more commands and append your commands as a YAML list. Other cloud-init features must be used explicitly.

# Cloud-init template for Debian 13 (Trixie).
define DEBIAN_13_CLOUD_INIT_USER_DATA_TEMPLATE
$(CLOUD_INIT_USER_DATA_TEMPLATE)
packages:
- build-essential
- libfoo-dev
endef
# Cloud-init user-data template for all versions of Ubuntu.
define UBUNTU_CLOUD_INIT_USER_DATA_TEMPLATE
$(CLOUD_INIT_USER_DATA_TEMPLATE)
packages:
- build-essential
- libfoo-dev
endef

HISTORY¶

Image garden was developed in stages throughout late 2023, with first commits appearing in early 2024.

BUGS¶

Known bugs can be listed by looking at GitLab issues.

AUTHORS¶

Zygmunt Krynicki <me@zygoon.pl>

March 18, 2025

image-garden 0.2

Source file:	image-garden.1.en.gz (from image-garden 0.2-2)
Source last updated:	2025-04-25T09:14:50Z
Converted to HTML:	2025-08-16T15:40:22Z