Some handy kubectl commands to make your life easier.Collected from some great resources I found out and some tweaks from their implementations. All credits goes to the original authors.

certificate-renewal.sh

$ cd /etc/kubernetes/pki/
$ mv {apiserver.crt,apiserver-etcd-client.key,apiserver-kubelet-client.crt,front-proxy-ca.crt,front-proxy-client.crt,front-proxy-client.key,front-proxy-ca.key,apiserver-kubelet-client.key,apiserver.key,apiserver-etcd-client.crt} ~/certs-bak
$ kubeadm init phase certs all
$ cd /etc/kubernetes/
$ mv {admin.conf,controller-manager.conf,kubelet.conf,scheduler.conf} ~/certs-bak
$ kubeadm init phase kubeconfig all
$ reboot

check-certificate-expire.sh

find /etc/kubernetes/pki/ -type f -name "*.crt" -print|egrep -v 'ca.crt$'|xargs -L 1 -t  -i bash -c 'openssl x509  -noout -text -in {}|grep After'

clear-evicted-pod.sh

kubectl get pod --all-namespaces --field-selector="status.phase==Failed"
kubectl delete pod --all-namespaces --field-selector 'status.phase==Failed'

kubectl get pod -n $NAMESPACE --field-selector="status.phase==Failed"
kubectl delete pod -n $NAMESPACE --field-selector 'status.phase==Failed'

cron-jobs.sh

# suspend cronjob via patch
kubectl patch cronjobs <job-name> -p '{"spec" : {"suspend" : true }}'

# delete completed cronjob pods
kubectl delete jobs --field-selector status.successful=1 

scale-all-deploy.sh

# scale all deployments under all namespaces.
for ns in $(kubectl get ns --no-headers | awk '{print $1}'); 
do for deploy in $(kubectl -n $ns get deploy --no-headers --ignore-not-found | awk '{print $1}'); 
do kubectl -n $ns scale deploy $deploy --replicas=1; done; 
done;

# scale all deployments under a namespace.
for i in $(kubectl get deploy -n $NAMESPACE | awk '{print $1}'); do kubectl scale deploy --replicas=1 -n $NAMESPACE $i; done

scale-all-sts.sh

# scale all statefulsets under all namespaces.
for ns in $(kubectl get ns --no-headers | awk '{print $1}'); 
do for sts in $(kubectl -n $ns get sts --no-headers --ignore-not-found | awk '{print $1}'); 
do kubectl -n $ns scale sts $sts --replicas=1; done; 
done;

# scale all statefulsets under a namespace.
for i in $(kubectl get sts -n $NAMESPACE | awk '{print $1}'); do kubectl scale sts --replicas=1 -n $NAMESPACE $i; done

Other useful commands can be found here Kubectl Kubernetes CheatSheet and kubectl Cheat Sheet

GG!

Thanks for this useful cmds!

• Deleting stuck ns

(
NAMESPACE=STUCK_NS
kubectl proxy &
kubectl get namespace $NAMESPACE -o json |jq '.spec = {"finalizers":[]}' > temp.json
curl -k -H "Content-Type: application/json" -X PUT --data-binary @temp.json 127.0.0.1:8001/api/v1/namespaces/$NAMESPACE/finalize
)

• Deleting stuck crd

kubectl patch crd/STUCK_CRD -p '{"metadata":{"finalizers":[]}}' --type=merge

Source
Source

Thanks bro