diff options
Diffstat (limited to 'recipes-containers/kubernetes/README.md')
| -rw-r--r-- | recipes-containers/kubernetes/README.md | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/recipes-containers/kubernetes/README.md b/recipes-containers/kubernetes/README.md new file mode 100644 index 00000000..ae79d6c2 --- /dev/null +++ b/recipes-containers/kubernetes/README.md @@ -0,0 +1,117 @@ +# k8s: Kubernetes + +meta-virtualization provides the recipes and packages suitable for a k8s +cluster instance. + +For a kubernetes controller: + + - packagegroup-k8s-host + +For a kubernetes worker/node: + + - packagegroup-k8s-node + +If kernel issues or missing features are detected, consider adding the +"kernel-modules" package to your image (Since the configuration and RDEPENDS +may not be correct for your kernel + k8s version). + +## CNI + +The CNI base packages provide core support and are installed by default as +dependencies of the kubernetes packages. Minimal configuration and startup +are provided, but you will need to apply the CNI configuration of your choice +after boot (see below fo an example) + +## Configure and initialize the host + +A convenience script "k8s-init" is provided to do basic setup on the controller +node. After the contoller boots, run it for kubeadm setup and other basic +configuration. + +Once the node is ready ('kubectl get nodes' to check), follow the instructions +for copying the token to your home directory, and apply the networking configuration +of choice (flannel in the example): + +```shell + % mkdir -p $HOME/.kube + % cp -i /etc/kubernetes/admin.conf $HOME/.kube/config + % chown $(id -u):$(id -g) $HOME/.kube/config + + % kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml +``` + +## Configuration and initialize the node/worker + +Once the kubernetes node has booted, it is ready to join the cluster. Some +basica configuration is done via the packages and a systctl.d configuration +snippet. + +Join the cluster (substitute your controller ip and token information): + +```shell +kubeadm join <controller ip>:6443 --token cq8ngi.6m6mgqi9zf08ypc4 --discovery-token-ca-cert-hash sha256:6064ae531c8dad824f9eadff030f83ec84d00796fac75f1adbd343255eb34fd2 +``` + +## Notes: + +Memory: + + if running under qemu, the default of 256M of memory is not enough, k3s will + OOM and exit. + + Boot with qemuparams="-m 2048" to boot with 2G of memory (or choose the + appropriate amount for your configuration) + +CPUs: + + Kubernetes needs at least two cpus, so ensure your qemuboot is smp of at + least 2, and/or that your hardware has the required capabilties. + +Disk: + + if using qemu and core-image* you'll need to add extra space in your disks + to ensure containers can start. The following in your image recipe, or + local.conf would add 2G of extra space to the rootfs: + +```shell +IMAGE_ROOTFS_EXTRA_SPACE = "2097152" +``` + +## Example qemux86-64 boot line: + +```shell +runqemu qemux86-64 nographic kvm slirp qemuparams="-m 2048" +``` +k8s logs can be seen via: + +```shell +% journalctl -u kubelet +``` + +or + +```shell +% journalctl -xe +``` + +## Example output from qemux86-64: + +If you've lost the join token, you can create a new one, or list existing +ones: + +```shell +root@qemux86-64-7b:~# kubeadm token create --print-join-command +kubeadm join 10.10.10.117:6443 --token dr71zq.y5vi3s2n2antvcej --discovery-token-ca-cert-hash sha256:6064ae531c8dad824f9eadff030f83ec84d00796fac75f1adbd343255eb34fd2 + +root@qemux86-64-7b:~# kubeadm token list +TOKEN TTL EXPIRES USAGES DESCRIPTION EXTRA GROUPS +cq8ngi.6m6mgqi9zf08ypc4 23h 2021-12-16T16:58:02Z authentication,signing The default bootstrap token generated by 'kubeadm init'. system:bootstrappers:kubeadm:default-node-token +dr71zq.y5vi3s2n2antvcej 23h 2021-12-16T17:46:28Z authentication,signing <none> system:bootstrappers:kubeadm:default-node-token +``` + +```shell +root@qemux86-64:~# kubectl get nodes +NAME STATUS ROLES AGE VERSION +qemux86-64-7b Ready control-plane,master 51m v1.23.1-rc.0.1+dd1b0a12471310-dirty +qemux86-64-9d Ready <none> 49m v1.23.1-rc.0.1+dd1b0a12471310-dirty +``` |