Cadvisor

As of Aug 2023 all production hosts run cadvisor; therefore it is possible to query any systemd unit resource usage (at the very least CPU and Memory usage). See also bug T108027 for more context on this work.

The https://grafana.wikimedia.org/d/lxIVOKq4k/units-resource-usage-overview allows you to inspect a given cluster resources broken down by unit name.

For in-cluster metrics of k8s-managed services (which also use cadvisor) see Kubernetes/Metrics.