fix(benchmarks): ensure all required families are present before extraction

The `getMetrics` already uses a guard before move on to
extractFromMetricFamilies checking for a single family cluster
`controller_runtime_reconcile_total`. However this can't vouch for the existence
of the other metric families in `mfs`. To make sure that the
`extractFromMetricFamilies` does not panic due to the empty maps, extend the
guard with checks to all the metricFamilies. Expect only to fail with timeout
in case that the map is not ready eventually.

This likely does not have any other significant overhead for the benchmark
results.

Signed-off-by: Ioannis Bonatakis <ybonatakis@suse.com>

Author: d3flex

benchmarks/record/record.go

@@ -233,6 +233,24 @@ func Metrics(experiment *gm.Experiment, suffix string) {
 	}
 }
 
+// requiredMetricFamilies lists every metric family that
+// extractFromMetricFamilies dereferences unconditionally. Some of these are
+// lazily created, e.g. rest_client_requests_total only appears after the
+// controller's first API request, so a scrape taken too early may miss them.
+var requiredMetricFamilies = []string{
+	"controller_runtime_reconcile_total",
+	"rest_client_requests_total",
+	"controller_runtime_reconcile_time_seconds",
+	"workqueue_adds_total",
+	"workqueue_queue_duration_seconds",
+	"workqueue_retries_total",
+	"workqueue_work_duration_seconds",
+	"go_gc_duration_seconds",
+	"process_cpu_seconds_total",
+	"process_network_receive_bytes_total",
+	"process_network_transmit_bytes_total",
+}
+
 func getMetrics(res map[string]float64, url string, controllers ...string) {
 	var (
 		mfs    map[string]*dto.MetricFamily
@@ -256,8 +274,10 @@ func getMetrics(res map[string]float64, url string, controllers ...string) {
 			return err
 		}
 
-		if _, ok := mfs["controller_runtime_reconcile_total"]; !ok {
-			return errors.New("controller_runtime_reconcile_total not found")
+		for _, name := range requiredMetricFamilies {
+			if _, ok := mfs[name]; !ok {
+				return errors.New(name + " not found")
+			}
 		}
 
 		return nil