cheatsheet.MD

Cheat Sheet for K8S

Short resource names

Full Resource Name	Short Resource Name
certificates	cert, certs
certificatesigningrequests	csr
certificiaterequests	cr, crs
componentstatuses	cs
configmaps	cm
cronjobs	cj
customresourcedefinitions	crd, crds
daemonsets	ds
deployments	deploy
endpoints	ep
events	ev
horizontalpodautoscalers	hpa
ingresses	ing
limitranges	limits
namespaces	ns
networkpolicies	netpol
nodes	no
persistentvolumeclaims	pvc
persistentvolumes	pv
pods	po
podsecuritypolicies	psp
priorityclasses	pc
replicasets	rs
replicasets	rs
replicationcontrollers	rc
resourcequotas	quota
scheduledscalers	ss
serviceaccounts	sa
services	svc
statefulsets	sts
storageclasses	sc

Labels

• Add label to resources

# Add label to the desired resources
kubectl label <resource> <key>=<value>

# Example adding label to node
kubectl label node1 isProd=false

# Example adding label to node
kubectl label node1 isProd=false --overwrite

# remove a label
kubectl label node1 isProd- # The [-] sign will delete the label

Set default namespace

kubectl     config \
            set-context $(kubectl config current-context) \
            --namespace=codewizard

Get Unused ConfigMaps

volumesCM=$( kubectl get pods -o jsonpath='{.items[*].spec.volumes[*].configMap.name}' | xargs -n1)
volumesProjectedCM=$( kubectl get pods -o jsonpath='{.items[*].spec.volumes[*].projected.sources[*].configMap.name}' | xargs -n1)
envCM=$( kubectl get pods -o jsonpath='{.items[*].spec.containers[*].env[*].ValueFrom.configMapKeyRef.name}' | xargs -n1)
envFromCM=$( kubectl get pods -o jsonpath='{.items[*].spec.containers[*].envFrom[*].configMapKeyRef.name}' | xargs -n1)

diff \
<(echo "$volumesCM\n$volumesProjectedCM\n$envCM\n$envFromCM" | sort | uniq) \
<(kubectl get configmaps -o jsonpath='{.items[*].metadata.name}' | xargs -n1 | sort | uniq)