https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/
https://vsupalov.com/yaml-kubernetes-examples-docs-spec/
kubectl explain service --recursive
https://kubernetes.io/docs/concepts/cluster-administration/manage-deployment/#organizing-resource-configurations https://stackoverflow.com/questions/50409392/why-should-i-specify-service-before-deployment-in-a-single-kubernetes-configurat