Build a minimal environment with Buildroot, enough for running kubeadm for Kubernetes.
So basically the "bigger brother" of boot2docker... Or a smaller version of minikube.iso.
| Interface | Implementation | Notes |
|---|---|---|
| Container Runtime | docker | cri-dockerd* |
| Container Networking | flannel | VXLAN backend |
| Container Storage | nfs | ReadWriteMany |
* Needed for Kubernetes 1.24 and later only
Written by Anders Björklund (@afbjorklund)
Kernel
- namespaces
- cgroups
- overlayfs
- nat
- bridge
- conntrack
- vxlan
User
- systemd
- glibc (required by systemd)
- docker
- containerd (required by dockerd)
- bash
- iptables
- conntrack (required since 1.18)
Bootable image:
x86_64
192M output/disk.img.gz
Flashable image:
aarch64
174M output/sdcard.img.zip
Kubernetes bin:
45M /usr/bin/kubeadm
46M /usr/bin/kubectl
116M /usr/bin/kubelet
Required images:
$ kubeadm config images list
registry.k8s.io/kube-apiserver:v1.28.8
registry.k8s.io/kube-controller-manager:v1.28.8
registry.k8s.io/kube-scheduler:v1.28.8
registry.k8s.io/kube-proxy:v1.28.8
registry.k8s.io/pause:3.9
registry.k8s.io/etcd:3.5.12-0
registry.k8s.io/coredns/coredns:v1.10.1Additional images:
docker.io/flannel/flannel:v0.23.0
docker pull (gzip):
33M images/registry.k8s.io/kube-apiserver_v1.28.8
32M images/registry.k8s.io/kube-controller-manager_v1.28.8
18M images/registry.k8s.io/kube-scheduler_v1.28.8
27M images/registry.k8s.io/kube-proxy_v1.28.8
304K images/registry.k8s.io/pause_3.9
54M images/registry.k8s.io/etcd_3.5.12-0
16M images/registry.k8s.io/coredns/coredns_v1.10.1
27M images/docker.io/flannel/flannel_v0.23.0
203M total
docker save | xz:
139M images.txz
Strms Blocks Compressed Uncompressed Ratio Check Filename
1 41 138,8 MiB 630,0 MiB 0,220 CRC32 images.txz
Device layout:
| QEMU | File | Media | Device | Used for | Size |
|---|---|---|---|---|---|
| -hda | disk.img | disk | /dev/sda | Persistent /var |
20g |
| -hdb | data.img | disk | /dev/sdb | Persistent /data |
5g |
| -hdc | buildroot.iso | cdrom | Buildroot booting | 137m | |
| -hdd | images.iso | cdrom | /dev/sdc | Kubernetes images | 160m |
Reference board:
pc (bios)
4.9M output/images/bzImage
84M output/images/rootfs.ext2
raspberrypi3-64
18M output/images/boot.vfat
75M output/images/rootfs.ext4