container-disk-images.md

KubeVirt container-disk images

The following images stored at dockerhub.com/kubevirt and can be used in Kubevirt tests:

• alpine-container-disk-demo Lightweight image for test suite.

• cirros-container-disk-demo Lightweight image for test suite.

• cirros-custom-container-disk-demo Used for e2e testing of custom base paths.

• fedora-cloud-container-disk-demo Fedora cloud edition image.

• fedora-sriov-lane-container-disk Fedora cloud edition image with contains all necessary configuration and drivers for sriov lane tests.

  • This image contained the packages:
    • kernel-modules (includes sriov drivers)
    • qemu-guest-agent
  • Configurations:
    • Enable and start qemu-guest-agent
    • Load kernel modules needed for sriov
      mlx4, mlx5, i40e, igb

How to create new customized container-disk for tests

Work-in-progress PR to automate this process kubevirt/kubevirtci#428

Customize an image can be done by:

• Editing the image with virt-customize
  Adding new package to an image for example:
  virt-customize -a "fedora32.qcow2" --install dpdk

• Spin-up live VM with the image you want using virt-install
  Once the VM is up apply the changes you want and when done shut down the VM gracefully with sudo shutdown -h now

Next, it is necessary to prepare the image so there will be no unique files or configurations
so each VM that will be created with the new image will have unique machine-id, mac-address etc.. We can do that with virt-sysprep:

virt-sysprep -a fedora32.qcow --operations machine-id,bash-history,logfiles,tmp-files,net-hostname,net-hwaddr  



Once the image is ready it is necessary to convert it to
container image with kubevirt/container-disk-v1alpha layer, so KubeVirt VM's can consume it according to
https://github.com/kubevirt/kubevirt/blob/main/docs/container-register-disks.md

cat > Dockerfile <<EOF
FROM kubevirt/container-disk-v1alpha
ADD fedora32.qcow2 /disk/
EOF

docker build -t kubevirt/fedora-sriov-testing:latest .

Use image in Kubevirt tests

First we need pull the image from the remote registry (or local registry) by adding container_pull rule to WORKSPACE file:

container_pull(
    name = "fedora_sriov_lane",
    # digest = ""
    registry = "localhost:5000",
    repository = "kubevirt/fedora-sriov-testing",
    tag = "latest",
)

Once you verified the image works reach out to kubevirt CI maintainers and ask to upload the new image then update the container_pull rule accordingly.

container_pull(
    name = "fedora_sriov_lane",
    digest = ""
    registry = "index.docker.io",
    repository = "kubevirt/fedora-sriov-testing",
    # tag = "32",
)

Next we need to add contaier_image rule for the new image to containerdisks/BUILD.bazel file;

container_image(
    name = "fedora-sriov-lane-container-disk-image",
    architecture = select({
        "@io_bazel_rules_go//go/platform:linux_arm64": "arm64",
        "//conditions:default": "amd64",
    }),
    base = select({
        "@io_bazel_rules_go//go/platform:linux_arm64": "@fedora_sriov_lane_aarch64//image",
        "//conditions:default": "@fedora_sriov_lane//image",
    }),
    visibility = ["//visibility:public"],
)

Then add new line for the container_bundle rule at the pojectsBUILD.bazel file

container_bundle(
    name = "build-other-images",
    images = {
        ...
        "$(container_prefix)/$(image_prefix)fedora-sriov-lane-container-disk:$(container_tag)": "//containerimages:fedora-extended-container-disk-image",
        ...
    }
)

Finally, in order to use the image in tests suite it is necessary to add it to tests/containerdisks/containerdisks.go file.