Kubernetes Notes

Find all images inside containers

kubectl get pods --all-namespaces -o jsonpath="{.items[*].spec.containers[*].image}" |\
tr -s '[[:space:]]' '\n' |\
sort |\
uniq -c

Get Limit Requests for all containers

kubectl get pod --all-namespaces --sort-by='.metadata.name' -o json | \
jq -r '[.items[] | {pod_name: .metadata.name, containers: .spec.containers[] | \
[ {container_name: .name, memory_requested: .resources.requests.memory, cpu_requested: .resources.requests.cpu} ] }]' | \
jq  'sort_by(.containers[0].cpu_requested)'

K8S list all container's image from a cluster

Kube (K8S) list all container’s image from a cluster

kubectl get pods --all-namespaces -o jsonpath="{.items[*].spec.containers[*].image}" |\
tr -s '[[:space:]]' '\n' |\
sort |\
uniq -c

kubectl check secrets certificates

kubectl get secret CERTNAME -o "jsonpath={.data['tls\.crt']}" | base64 -D | openssl x509 -enddate -noout

kubectl basic commands

# connect on Pods
kubectl exec -it --namespace=develop my-pod-id -- /bin/ash
# Show pod network on cluster
kubectl get nodes -o jsonpath='{.items[*].spec.podCIDR}'
# Show Pods by <node>
kubectl get pods --all-namespaces -o wide --field-selector spec.nodeName=<node>
# sorting pods
kubectl get pods -o wide --sort-by="{.spec.nodeName}"

kubernetes volume protected

This happens when persistent volume is protected. You should be able to cross verify this:

Command:

kubectl describe pvc PVC_NAME | grep Finalizers

Output:
Finalizers:    [kubernetes.io/pvc-protection]

You can fix this by setting finalizers to null using kubectl patch:

kubectl patch pvc PVC_NAME -p '{"metadata":{"finalizers": []}}' --type=merge

EKS CPUthrotting

docker run --cpus CPUS -it python python -m timeit -s 'import hashlib' -n 10000 -v 'haslib.sha512().update(b"foo")'