I was trying to install Prometheus and Grafana in one of my Kube clusters. So I download Prometheus and Grafana helm repos, to my surprise most of the predefined dashboards that I found were not working, so I spent hours figuring out why; there were some missing metrics and components not installed by default. At the end, I was able to make some of those work.
For days, I thought that there was not a prebuilt Grafana/Prometheus dashboard solution until I took a look into Rancher, in their documentation they make a reference to Kube-Prometheus-Stack. Not sure why I did not find this helm chart before, it already contains a full set of Grafana dashboards that will help you monitoring Kubernetes (pods, workloads, namespaces, etc).
Here is the link to the Helm Chart.