Building Multi-Arch Images, Rootless Mode, and Example Kubernetes Builder Creation

of a node. A Buildx node in this case could connect multiple Kubernetes nodes of the same architecture together. With the `kube` builder created, you can now introduce another architecture into the mix using `--append`. For example, to add `arm64`: ```console $ docker buildx create \ --append \ --bootstrap \ --name=kube \ --driver=kubernetes \ --platform=linux/arm64 \ --node=builder-arm64 \ --driver-opt=namespace=buildkit,nodeselector="kubernetes.io/arch=arm64" ``` Listing your builders shows both nodes for the `kube` builder: ```console $ docker buildx ls NAME/NODE DRIVER/ENDPOINT STATUS PLATFORMS kube kubernetes builder-amd64 kubernetes:///kube?deployment=builder-amd64&kubeconfig= running linux/amd64*, linux/amd64/v2, linux/amd64/v3, linux/386 builder-arm64 kubernetes:///kube?deployment=builder-arm64&kubeconfig= running linux/arm64* ``` You can now build multi-arch `amd64` and `arm64` images, by specifying those platforms together in your build command: ```console $ docker buildx build --builder=kube --platform=linux/amd64,linux/arm64 -t <user>/<image> --push . ``` You can repeat the `buildx create --append` command for as many architectures that you want to support. ## Rootless mode The Kubernetes driver supports rootless mode. For more information on how rootless mode works, and its requirements, see [here](https://github.com/moby/buildkit/blob/master/docs/rootless.md). To turn it on in your cluster, you can use the `rootless=true` driver option: ```console $ docker buildx create \ --name=kube \ --driver=kubernetes \ --driver-opt=namespace=buildkit,rootless=true ``` This will create your pods without `securityContext.privileged`. Requires Kubernetes version 1.19 or later. Using Ubuntu as the host kernel is recommended. ## Example: Creating a Buildx builder in Kubernetes This guide shows you how to: - Create a namespace for your Buildx resources - Create a Kubernetes builder. - List the available builders - Build an image using your Kubernetes builders Prerequisites: - You have an existing Kubernetes cluster. If you don't already have one, you can follow along by installing [minikube](https://minikube.sigs.k8s.io/docs/). - The cluster you want to connect to is accessible via the `kubectl` command,

This section details how to build multi-architecture images using `docker buildx` with the Kubernetes driver, including appending architectures and specifying platforms. It also covers enabling rootless mode using the `rootless=true` driver option. Finally, it provides a guide for creating a Buildx builder within a Kubernetes cluster, outlining the prerequisites and steps for creating a namespace, builder, listing builders, and building an image.