2.4 KiB
Cluster Operations
Delete evicted pods across all namespaces
kubectl get pods --all-namespaces -o json | jq '.items[] | select(.status.reason!=null) | select(.status.reason | contains("Evicted")) | "kubectl delete pods \(.metadata.name) -n \(.metadata.namespace)"' | xargs -n 1 bash -c
cleanup stuck namespace
for ns in $(kubectl get ns --field-selector status.phase=Terminating -o jsonpath='{.items[*].metadata.name}'); do kubectl get ns $ns -ojson | jq '.spec.finalizers = []' | kubectl replace --raw "/api/v1/namespaces/$ns/finalize" -f -; done
Cleanup old replicasets
kubectl get rs --all-namespaces | awk {' if ($3 == 0 && $4 == 0) system("kubectl delete rs "$2" --namespace="$1)'}
Replace worker nodes
In order to change the instance type or in genernal replace worker nodes do:
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(optional) Update the launch configuration of the worker group
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Make sure there is enough capacity in the cluster to handle all pods being evicted for the node
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kubectl drain --ignore-daemonsets node_name
will evict all pods except DaemonSets. In case there are pods with local storage review each affected pod.
After being sure no important data will be lost add--delete-local-datato the original command above and try again. -
Terminate instance matching node_name
The new instance should take over the previous node_name assuming only node is being replaced at a time and automatically join and replace the previous node.
kubectl
kubectl is the basic cmdline tool to interact with any kubernetes cluster via the kube-api server
Plugins
As there are various very useful plugins for kubectl the first thing should be to install krew the plugin manager.
See: https://github.com/kubernetes-sigs/krew for details
List of awesome plugins: https://github.com/ishantanu/awesome-kubectl-plugins
kubelogin
To login / authenticate against an openID provider like Google install the kubelogin plugin.
See: https://github.com/int128/kubelogin
Make sure to adjust your kubeconfig files accordingly !
kauthproxy
Easiest way to access the Kubernetes dashboard, if installed in the targeted cluster, is to use the kauthproxy plugin.
See: https://github.com/int128/kauthproxy
Once installed simply execute:
kubectl auth-proxy -n kubernetes-dashboard https://kubernetes-dashboard.svc
and access the dashboard via the automatically opened browser window.