avocado.utils.vmimage

This utility provides an API to download/cache VM images (QCOW) from the official distributions repositories.

Basic Usage

Import vmimage module:

>>> from avocado.utils import vmimage

Get an image, which consists in an object with the path of the downloaded/cached base image and the path of the external snapshot created out of that base image:

>>> image = vmimage.Image.from_parameters()
>>> image
<Image name=Fedora version=35 arch=x86_64>
>>> image.name
'Fedora'
>>> image.path
'/tmp/by_location/951337e4bd3f30b584623d46f1745147cb32aca5/Fedora-Cloud-Base-35-1.2.x86_64-54d81da8.qcow2'
>>> image.version
35
>>> image.base_image
'/tmp/by_location/951337e4bd3f30b584623d46f1745147cb32aca5/Fedora-Cloud-Base-35-1.2.x86_64.qcow2'

If you provide more details about the image, the object is expected to reflect those details:

>>> image = vmimage.Image.from_parameters(arch='aarch64)
>>> image
<Image name=Fedora version=35 arch=aarch64>
>>> image.name
'Fedora'
>>> image.path
'/tmp/by_location/3f1d3b1b568ad908eb003d1012ba79e1f3bb0d57/Fedora-Cloud-Base-35-1.2.aarch64-dab7007f.qcow2'

>>> image = vmimage.Image.from_parameters(version=34,name='fedora')
>>> image
<Image name=Fedora version=34 arch=x86_64>
>>> image.path
'/tmp/by_location/def0ea887952961473cfbfda268e77d66f9bcd14/Fedora-Cloud-Base-34-1.2.x86_64-0ed30cd9.qcow2'

Notice that, unlike the base_image attribute, the path attribute will be always different in each instance, as it actually points to an external snapshot created out of the base image:

>>> i1 = vmimage.Image.from_parameters()
>>> i2 = vmimage.Image.from_parameters()
>>> i1.path == i2.path
False

Custom Image Provider

If you need your own Image Provider, you can extend the vmimage.IMAGE_PROVIDERS list, including your provider class. For instance, using the vmimage utility in an Avocado test, we could add our own provider with:

from avocado import Test

from avocado.utils import vmimage

class MyProvider(vmimage.ImageProviderBase):

    name = 'MyDistro'

    def __init__(self, version='[0-9]+', build='[0-9]+.[0-9]+',
                 arch=os.uname()[4]):
        """
        :params version: The regular expression that represents
                         your distro version numbering.
        :params build: The regular expression that represents
                       your build version numbering.
        :params arch: The default architecture to look images for.
        """
        super(MyProvider, self).__init__(version, build, arch)

        # The URL which contains a list of the distro versions
        self.url_versions = 'https://dl.fedoraproject.org/pub/fedora/linux/releases/'

        # The URL which contains a list of distro images
        self.url_images = self.url_versions + '{version}/CloudImages/{arch}/images/'

        # The images naming pattern
        self.image_pattern = 'Fedora-Cloud-Base-{version}-{build}.{arch}.qcow2$'

class MyTest(Test):

    def setUp(self):
        vmimage.IMAGE_PROVIDERS.add(MyProvider)
        image = vmimage.get('MyDistro')
        ...

    def test(self):
        ...

Supported images

The vmimage library has no hardcoded limitations of versions or architectures that can be supported. You can use it as you wish. This is the list of images that we tested and they work with vmimage:

Provider	Version	Architecture
centos	8	aarch64
centos	8	ppc64le
centos	8	x86_64
centos	7	x86_64
cirros	0.5.2	arm
cirros	0.5.2	aarch64
cirros	0.5.2	i386
cirros	0.5.2	ppc64
cirros	0.5.2	ppc64le
cirros	0.5.2	powerpc
cirros	0.5.2	x86_64
cirros	0.4.0	arm
cirros	0.4.0	aarch64
cirros	0.4.0	i386
cirros	0.4.0	ppc64
cirros	0.4.0	ppc64le
cirros	0.4.0	powerpc
cirros	0.4.0	x86_64
debian	buster	arm64
debian	buster	amd64
debian	bullseye	arm64
debian	bullseye	amd64
fedora	34	aarch64
fedora	34	ppc64le
fedora	34	s390x
fedora	34	x86_64
fedora	35	aarch64
fedora	35	ppc64le
fedora	35	s390x
fedora	35	x86_64
fedora	36	aarch64
fedora	36	ppc64le
fedora	36	s390x
fedora	36	x86_64
ubuntu	18.04	aarch64
ubuntu	18.04	ppc64el
ubuntu	18.04	s390x
ubuntu	18.04	x86_64
ubuntu	20.10	aarch64
ubuntu	20.10	ppc64el
ubuntu	20.10	s390x
ubuntu	20.10	x86_64
ubuntu	21.04	aarch64
ubuntu	21.04	ppc64el
ubuntu	21.04	s390x
ubuntu	21.04	x86_64
ubuntu	21.10	aarch64
ubuntu	21.10	ppc64el
ubuntu	21.10	s390x
ubuntu	21.10	x86_64
opensuse	15.2	x86_64
opensuse	15.3	x86_64
freebsd	13.0	aarch64
freebsd	13.0	i386
freebsd	13.0	x86_64
freebsd	12.2	aarch64
freebsd	12.2	i386
freebsd	12.2	x86_64