Something which has been lost is RTFM. Anything tool, library or language you want to use you better get comfortable with the idea you'll have to read documenta

Something which has been lost is RTFM. Anything tool, library or language you want to use you better get comfortable with the idea you'll have to read documentation (or RFC). Pasting code you don't really understand from anywhere is not how you'll master something, that's how you'll brick a VM trying to extend some partition. Multiple times. But telling people to RTFM instead of giving the answer is rude now. Also tutorials should take more time to show to watchers / readers how to get the information they distill. Simple example with our friend k8s: most tutorials will just give you some generic Deployment yaml. Never explaining (or only at surface level) those labels and selector. Especially why you want your spec.selector to match spec.template.labels. Tutorials should link first to the Deployment documentation https://kubernetes.io/docs/reference/kubernetes-api/workload-resources/deployment-v1/ https://kubernetes.io/docs/reference/kubernetes-api/workload... where you'll find a link to the selector specification https://kubernetes.io/docs/reference/kubernetes-api/common-definitions/label-selector/#LabelSelector https://kubernetes.io/docs/reference/kubernetes-api/common-d... explaining how it matches labels and on the Deployment page you also see that your spec.template is in fact a PodTemplate which is why you want the deployment selectors to match those Pods label. 90% of examples you'll find tend to use the same names for everything because they do simple things but when you try to do something a little more complex suddenly they don't help learning which names can be changed and what it entails. Traefik gets a gold star for having part of their annotations names being meaningful.