buildroot4kubernetes
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
176M output/disk.img.gz
Flashable image:
aarch64
174M output/sdcard.img.zip
Kubernetes bin:
43M /usr/bin/kubeadm
44M /usr/bin/kubectl
111M /usr/bin/kubelet
Required images:
$ kubeadm config images list
k8s.gcr.io/kube-apiserver:v1.24.0
k8s.gcr.io/kube-controller-manager:v1.24.0
k8s.gcr.io/kube-scheduler:v1.24.0
k8s.gcr.io/kube-proxy:v1.24.0
k8s.gcr.io/pause:3.7
k8s.gcr.io/etcd:3.5.3-0
k8s.gcr.io/coredns/coredns:v1.8.6docker images:
linux/amd64
REPOSITORY TAG IMAGE ID CREATED SIZE
k8s.gcr.io/kube-apiserver v1.24.0 529072250ccc 29 hours ago 130MB
k8s.gcr.io/kube-proxy v1.24.0 77b49675beae 29 hours ago 110MB
k8s.gcr.io/kube-scheduler v1.24.0 e3ed7dee73e9 29 hours ago 51MB
k8s.gcr.io/kube-controller-manager v1.24.0 88784fb4ac2f 29 hours ago 119MB
k8s.gcr.io/pause 3.7 221177c6082a 7 weeks ago 711kB
k8s.gcr.io/etcd 3.5.3-0 aebe758cef4c 2 weeks ago 299MB
k8s.gcr.io/coredns/coredns v1.8.6 a4ca41631cc7 6 months ago 46.8MB
k8s.gcr.io/pause 3.6 6270bb605e12 9 months ago 683kB
flannelcni/flannel v0.17.0 9247abf08677 2 months ago 59.8MB
linux/arm64
REPOSITORY TAG IMAGE ID CREATED SIZE
k8s.gcr.io/kube-apiserver v1.24.0 b62a103951f4 2 weeks ago 126MB
k8s.gcr.io/kube-proxy v1.24.0 66e1443684b0 2 weeks ago 106MB
k8s.gcr.io/kube-scheduler v1.24.0 b81513b3bfb4 2 weeks ago 50MB
k8s.gcr.io/kube-controller-manager v1.24.0 59fad34d4fe0 2 weeks ago 116MB
k8s.gcr.io/pause 3.7 e5a475a03805 2 months ago 514kB
k8s.gcr.io/etcd 3.5.3-0 a9a710bb96df 5 weeks ago 178MB
k8s.gcr.io/coredns/coredns v1.8.6 edaa71f2aee8 7 months ago 46.8MB
k8s.gcr.io/pause 3.6 7d46a07936af 9 months ago 484kB
flannelcni/flannel v0.17.0 a8fbfb17608d 2 months ago 61.8MB
docker pull (gzip):
32M images/k8s.gcr.io/kube-apiserver_v1.24.0
37M images/k8s.gcr.io/kube-proxy_v1.24.0
15M images/k8s.gcr.io/kube-scheduler_v1.24.0
29M images/k8s.gcr.io/kube-controller-manager_v1.24.0
292K images/k8s.gcr.io/pause_3.7
97M images/k8s.gcr.io/etcd_3.5.3-0
13M images/k8s.gcr.io/coredns/coredns_v1.8.6
19M images/docker.io/flannelcni/flannel_v0.17.0
240M total
docker save | xz:
166M images.txz
Strms Blocks Compressed Uncompressed Ratio Check Filename
1 50 165.4 MiB 776.0 MiB 0.213 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
