Updates #2784 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This lets us publish sets of vars that are breakdowns along one dimension in a format that Prometheus and Grafana natively know how to do useful things with. Signed-off-by: David Anderson <dave@natulte.net>
And add some opinions. Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>