Building Images for vSphere


The images may be built using one of the following hypervisors:

OSBuilderBuild target
LinuxVMware Workstation (vmware-iso)build-node-ova-local-
macOSVMware Fusion (vmware-iso)build-node-ova-local-
vSpherevSphere >= 6.5build-node-ova-vsphere-
vSpherevSphere >= 6.5build-node-ova-vsphere-base-
vSphere ClonevSphere >= 6.5build-node-ova-vsphere-clone-
LinuxVMware Workstation (vmware-vmx)build-node-ova-local-vmx-
macOSVMware Fusion (vmware-vmx)build-node-ova-local-vmx-

NOTE If you want to build all available OS’s, uses the -all target. If you want to build them in parallel, use make -j. For example, make -j build-node-ova-local-all.

The vsphere builder supports building against a remote VMware vSphere using standard API.

vmware-vmx builder

During the dev process it’s uncommon for the base OS image to change, but the image building process builds the base image from the ISO every time and thus adding a significant amount of time to the build process.

To reduce the image building times during development, one can use the build-node-ova-local-base-<OS> target to build the base image from the ISO. By setting source_path variable in vmx.json to the *.vmx file from the output, it can then be re-used with the build-node-ova-local-vmx-<OS> build target to speed up the process.

vsphere-clone builder

vsphere-base builder allows you to build one time base OVAs from iso images using the kickstart process. It leaves the user builder intact in base OVA to be used by clone builder later. vSphere-clone builder builds on top of base OVA by cloning it and ansiblizing it. This saves time by allowing repeated iteration on base OVA without installing OS from scratch again and again. Also, it uses link cloning and create_snapshot feature to clone faster.

Prerequisites for vSphere builder

Complete the vsphere.json configuration file with credentials and informations specific to the remote vSphere hypervisor used to build the ova file. This file must have the following format (cluster can be replace by host):

    "vcenter_server":"FQDN of vcenter",
    "folder": "template_folder_on_vcenter",
    "cluster": "esxi_cluster_used_for_template_creation",
    "network": "network_attached_to_template",
    "insecure_connection": "false",
    "template": "base_template_used_by_clone_builder",
    "create_snbapshot": "creates a snaphot on base OVA after building",
    "linked_clone": "Uses link cloning in vsphere-clone builder: true, by default"

If you prefer to use a different configuration file, you can create it with the same format and export PACKER_VAR_FILES environment variable containing the full path to it.

Building Images

The build prerequisites for using image-builder for building OVAs are managed by running:

make deps-ova

From the images/capi directory, run make build-node-ova-<hypervisor>-<OS>, where <hypervisor> is your target hypervisor (local or vsphere) and <OS> is the desired operating system. The available choices are listed via make help.

OVA Creation

When the final OVA is created, there are two methods that can be used for creation. By default, an OVF file is created, the manifest is created using SHA256 sums of the OVF and VMDK, and then tar is used to create an OVA containing the OVF, VMDK, and the manifest.

Optionally, ovftool can be used to create the OVA. This has the advantage of validating the created OVF, and has greater chances of producing OVAs that are compliant with more versions of VMware targets of Fusion, Workstation, and vSphere. To use ovftool for OVA creation, set the env variable IB_OVFTOOL to any non-empty value. Optionally, args to ovftool can be passed by setting the env var IB_OVFTOOL_ARGS like the following:

IB_OVFTOOL=1 IB_OVFTOOL_ARGS="--allowExtraConfig" make build-node-ova-<hypervisor>-<OS>


In addition to the configuration found in images/capi/packer/config, the ova directory includes several JSON files that define the configuration for the images:

centos-7.jsonThe settings for the CentOS 7 image
flatcar.jsonThe settings for the Flatcar image
photon-3.jsonThe settings for the Photon 3 image
photon-4.jsonThe settings for the Photon 4 image
rhel-7.jsonThe settings for the RHEL 7 image
ubuntu-1804.jsonThe settings for the Ubuntu 18.04 image
ubuntu-2004.jsonThe settings for the Ubuntu 20.04 image
ubuntu-2204.jsonThe settings for the Ubuntu 22.04 image
vsphere.jsonAdditional settings needed when building on a remote vSphere

Photon specific options

Enabling .local lookups via DNS

Photon uses systemd-resolved defaults, which means that .local will be resolved using Multicast DNS. If you are deploying to an environment where you require DNS resolution .local, then add leak_local_mdns_to_dns=yes in ansible_user_vars.


When building the RHEL image, the OS must register itself with the Red Hat Subscription Manager (RHSM). To do this, the current supported method is to supply a username and password via environment variables. The two environment variables are RHSM_USER and RHSM_PASS. Although building RHEL images has been tested via this method, if an error is encountered during the build, the VM is deleted without the machine being unregistered with RHSM. To prevent this, it is recommended to build with the following command:

PACKER_FLAGS=-on-error=ask RHSM_USER=user RHSM_PASS=pass make build-node-ova-<hypervisor>-rhel-7

The addition of PACKER_FLAGS=-on-error=ask means that if an error is encountered, the build will pause, allowing you to SSH into the machine and unregister manually.


The images are built and located in images/capi/output/BUILD_NAME+kube-KUBERNETES_VERSION

Uploading Images

The images are uploaded to the GCS bucket capv-images. The path to the image depends on the version of Kubernetes:

Build typeUpload location

Uploading the images requires the gcloud and gsutil programs, an active Google Cloud account, or a service account with an associated key file. The latter may be specified via the environment variable KEY_FILE.

hack/ --key-file KEY_FILE BUILD_DIR

First the images are checksummed (SHA256). If a matching checksum already exists remotely then the image is not re-uploaded. Otherwise the images are uploaded to the GCS bucket.

Listing Available Images

Once uploaded the available images may be listed using the gsutil program, for example:

gsutil ls gs://capv-images/release

Downloading Images

Images may be downloaded via HTTP:

Build typeDownload location

Testing Images

Accessing the Images

Accessing Local VMs

After the images are built, the VMs from they are built are prepped for local testing. Simply boot the VM locally with Fusion or Workstation and the machine will be initialized with cloud-init data from the cloudinit directory. The VMs may be accessed via SSH by using the command hack/ BUILD_DIR capv.

Accessing Remote VMs

After deploying an image to vSphere, use hack/ VM to snapshot the image and update it with cloud-init data from the cloudinit directory. Start the VM and now it may be accessed with ssh -i cloudinit/id_rsa.capi capv@VM_IP. This hack necessitate the govc utility from VMmare

Initialize a CNI

As root:

(copied from containernetworking/cni)

mkdir -p /etc/cni/net.d
curl -LO
tar -xzf cni-plugins-amd64-v0.7.0.tgz --directory /etc/cni/net.d
cat >/etc/cni/net.d/10-mynet.conf <<EOF
    "cniVersion": "0.2.0",
    "name": "mynet",
    "type": "bridge",
    "bridge": "cni0",
    "isGateway": true,
    "ipMasq": true,
    "ipam": {
        "type": "host-local",
        "subnet": "",
        "routes": [
            { "dst": "" }
cat >/etc/cni/net.d/99-loopback.conf <<EOF
    "cniVersion": "0.2.0",
    "name": "lo",
    "type": "loopback"

Run the e2e node conformance tests

As a non-root user:

curl -LO$(</etc/kubernetes-version)/kubernetes-test-linux-amd64.tar.gz
tar -zxvf kubernetes-test-linux-amd64.tar.gz
cd kubernetes/test/bin
sudo ./ginkgo --nodes=8 --flakeAttempts=2 --focus="\[Conformance\]" --skip="\[Flaky\]|\[Serial\]|\[sig-network\]|Container Lifecycle Hook" ./e2e_node.test -- --k8s-bin-dir=/usr/bin --container-runtime=remote --container-runtime-endpoint unix:///var/run/containerd/containerd.sock --container-runtime-process-name /usr/local/bin/containerd --container-runtime-pid-file= --kubelet-flags="--cgroups-per-qos=true --cgroup-root=/ --runtime-cgroups=/system.slice/containerd.service" --extra-log="{\"name\": \"containerd.log\", \"journalctl\": [\"-u\", \"containerd\"]}"

The cloudinit Directory

The cloudinit contains files that:

  • Are example data used for testing
  • Are not included in any of the images
  • Should not be used in production systems

For more information about how the files in the cloudinit directory are used, please refer to the section on accessing the images.