enhance test metrics (#13262)

helper/testhelpers/testhelpers.go

@@ -690,15 +690,46 @@ func SysMetricsReq(client *api.Client, cluster *vault.TestCluster, unauth bool)
 }
 
 type SysMetricsJSON struct {
-	Gauges []GaugeJSON `json:"Gauges"`
+	Gauges   []gaugeJSON   `json:"Gauges"`
+	Counters []counterJSON `json:"Counters"`
+
+	// note: this is referred to as a "Summary" type in our telemetry docs, but
+	// the field name in the JSON is "Samples"
+	Summaries []summaryJSON `json:"Samples"`
 }
 
-type GaugeJSON struct {
+type baseInfoJSON struct {
 	Name   string                 `json:"Name"`
-	Value  int                    `json:"Value"`
 	Labels map[string]interface{} `json:"Labels"`
 }
 
+type gaugeJSON struct {
+	baseInfoJSON
+	Value int `json:"Value"`
+}
+
+type counterJSON struct {
+	baseInfoJSON
+	Count  int     `json:"Count"`
+	Rate   float64 `json:"Rate"`
+	Sum    int     `json:"Sum"`
+	Min    int     `json:"Min"`
+	Max    int     `json:"Max"`
+	Mean   float64 `json:"Mean"`
+	Stddev float64 `json:"Stddev"`
+}
+
+type summaryJSON struct {
+	baseInfoJSON
+	Count  int     `json:"Count"`
+	Rate   float64 `json:"Rate"`
+	Sum    float64 `json:"Sum"`
+	Min    float64 `json:"Min"`
+	Max    float64 `json:"Max"`
+	Mean   float64 `json:"Mean"`
+	Stddev float64 `json:"Stddev"`
+}
+
 // SetNonRootToken sets a token on :client: with a fairly generic policy.
 // This is useful if a test needs to examine differing behavior based on if a
 // root token is passed with the request.