资料来源: https://github.com/walidshaari/Kubernetes-Certified-Administrator
先执行
source (kubectl completion bash)
提示
练习、练习、再练习
熟悉文档，主要包括 concepts 和 tasks
https://kubernetes.io/docs/concepts/
https://kubernetes.io/docs/tasks/-
尽量熟悉 kubectl 命令，例如
kubectl explain --recursive source <(kubectl completion bash) alias k=kubectl complete -F __start_kubectl k kubectl get pod -A -owide --show-labels --sort-by='{.metadata.name}' kubectl describe pod {podname} kubectl logs {podname} kubectl run testpod --image=nginx --dry-run=client -oyaml
Cluster Architecture, Installation, and Configuration 25%
etcd backup and restore brief
export ETCDCTL_API=3 # needed to specify etcd api versions, not sure if it is needed anylonger with k8s 1.19+
etcdctl snapshot save -h #find save options
etcdctl snapshot restore -h #find restore options
# possible example of save, options will change depending on cluster context, as TLS is used need to give ca,crt, and key paths
etcdctl snapshot save /backup/snapshot.db \
--cert=/etc/kubernetes/pki/etcd/server.crt \
--key=/etc/kubernetes/pki/etcd/server.key \
--cacert=/etc/kubernetes/pki/etcd/ca.crt
evicting pods/nodes and bringing back node back to cluster
kubectl drain <node> # to drain a node
kubectl uncordon <node> # to return a node after updates back to the cluster from unscheduled state to Ready
kubectl cordon <node> # to not schedule new pods on a node
upgrade kubernetes worker node
kubectl drain <node>
apt-get upgrade -y kubeadm=<k8s-version-to-upgrade>
apt-get upgrade -y kubelet=<k8s-version-to-upgrade>
kubeadm upgrade node config --kubelet-version <k8s-version-to-upgrade>
systemctl restart kubelet
kubectl uncordon <node>
kubeadm upgrade steps
kubeadm upgrade plan
kubeadm upgrade apply
Troubleshooting – 30%
如何监控应用？
https://kubernetes.io/docs/tasks/debug-application-cluster/resource-usage-monitoring/
应用为什么失败？
https://kubernetes.io/docs/tasks/debug-application-cluster/debug-application/
集群为什么出问题了？
https://kubernetes.io/docs/tasks/debug-application-cluster/debug-cluster/
DNS为什么不能解析了？
https://kubernetes.io/docs/tasks/administer-cluster/dns-debugging-resolution/
