runner-metrics runs on a Ubicloud host inside a GitHub runner VM's network
namespace. It accepts resource metrics the guest posts to
http://[fd00:0b1c:100d:57a7::]:9000/metrics, keeps allowlisted metrics,
stamps them with the VM's labels from METRICS_DIR/labels.json, and writes
them to METRICS_DIR/done for the host to forward to VictoriaMetrics.
$ go build -ldflags "-s -w -X main.version=`cat version.txt`"
$ runner-metrics METRICS_DIR
AGPL