repository·main·Indexed 20 days ago
https://github.com/kubernetes-sigs/image-builderA tool for building Kubernetes virtual machine images across multiple infrastructure providers, optimized for Cluster API and compatible with Kubeadm-based setups. It supports various targets including MaaS, Proxmox, QEMU, and Flatcar, with capabilities for installing GPU drivers (NVIDIA, AMD), configuring security tools like Trivy and Falco, and managing Ignition files for Flatcar builds.
Kubernetes Image Builder is a SIG Cluster Lifecycle sponsored project designed to build Kubernetes virtual machine (VM) images across multiple infrastructure providers.
Primary Use Case:
The resulting VM images are specifically intended for use with Cluster API, though they are also suitable for any setup that relies on kubeadm.
Image Builder is a tool designed to build Kubernetes virtual machine (VM) images across multiple infrastructure providers.
Key characteristics:
Kubeadm.This glossary defines key terms, acronyms, and external technologies used within the Image Builder ecosystem. Key categories include:
packer-provisioner-goss to test if images contain the necessary components for Cluster API.To load extra container images or executables, you must set load_additional_components to "true". You can then specify the types of components to load:
additional_url_images: Load images from a tar URL (requires additional_url_images_list).additional_registry_images: Load images from a registry (requires additional_registry_images_list).additional_executables: Load executables from a URL (requires additional_executables_list and additional_executables_destination_path).additional_s3: Load components from an S3-compatible endpoint.{
"additional_executables": "true",
"additional_executables_destination_path": "/path/to/dest",
"additional_executables_list": "http://path/to/exec1,http://path/to/exec2",
"additional_s3": "true",
"additional_s3_endpoint": "https://path-to-s3-endpoint",
"additional_s3_access": "S3_ACCESS_KEY",
"additional_s3_secret": "S3_SECRET_KEY",
"additional_s3_bucket": "some-bucket",
"additional_s3_object": "path/to/object",
"additional_s3_destination_path": "/path/to/dest",
"additional_s3_ceph": "true",
"additional_registry_images": "true",
"additional_registry_images_list": "plndr/kube-vip:0.3.4,plndr/kube-vip:0.3.3",
"additional_url_images": "true",
"additional_url_images_list": "http://path/to/image1.tar,http://path/to/image2.tar",
"load_additional_components": "true"
}/curtin directory within the role.By default, the resulting image follows the naming format: <OS>-kube-<KUBERNETES_SEMVER> (for example, ubuntu-2204-kube-v1.23.15).
You can override this default name by setting the image_name key in your OpenStack variables JSON file.
The vmware-vmx builder is optimized for local development. To avoid the time-consuming process of building the base image from an ISO every time, you can use the build-node-ova-local-base-<OS> target to create a base image.
By setting the source_path variable in vmx.json to the *.vmx file produced by the base build, you can then use the build-node-ova-local-vmx-<OS> target to build subsequent images much faster.
For a successful build, the following networking conditions must be met:
make commands.Image Builder creates Cluster API (CAPI) images using Make targets defined in images/capi/Makefile.
Each target name determines two things:
packer/qemu/packer.json).packer/qemu/qemu-ubuntu-2404.json).Targets also include common Linux node variables from packer/config/*.json.
Key distinction:
PACKER_VAR_FILES environment variable to override variables for an existing target without creating a new target.Example: make build-qemu-ubuntu-2404 builds the image, while make validate-qemu-ubuntu-2404 validates the configuration without performing a build.
Goss is a YAML-based tool used to validate a server's configuration. In the context of Image Builder, it is used alongside packer-provisioner-goss to ensure that images contain all the necessary components required to work with Cluster API (CAPI).
Goss runs automatically as part of the image building process via a Packer provisioner. Configuration for this process is managed through packer/config/goss-args.json.
Image-builder supports two methods for configuring Windows services (specifically for kubelet):
{{ kubernetes_install_path }}\StartKubelet.ps1. This allows for easy editing of command arguments within the startup file. Nssm also handles service restarts automatically.sc.exe utility. This requires using the kubelet argument --windows-service to install kubelet as a native service.Important Considerations:
sc.exe, you must manually configure service restart options on kubelet, as it lacks the automatic restart handling provided by nssm.sc.exe does not support kubeadm KUBELET_KUBEADM_ARGS, which is required by Cluster API to pass extra user arguments.manual startup by default. You may want to change this to automatic once the node has successfully joined a cluster.The vsphere-clone builder is designed for rapid iteration. It works in conjunction with the vsphere-base builder:
vsphere-base builder: Builds a one-time base OVA from an ISO using the kickstart process. It leaves the builder intact within the base OVA.vsphere-clone builder: Builds on top of the base OVA by cloning it and applying configurations via Ansible.This approach saves time by using link cloning and the create_snapshot feature, avoiding the need to reinstall the OS from scratch for every build iteration.