fix some tests that were broken from the TelemetryConfig change

agent/config/runtime_test.go

@@ -8,7 +8,6 @@ import (
 	"errors"
 	"flag"
 	"fmt"
-	"github.com/armon/go-metrics/prometheus"
 	"io/ioutil"
 	"net"
 	"os"
@@ -19,6 +18,8 @@ import (
 	"testing"
 	"time"
 
+	"github.com/armon/go-metrics/prometheus"
+
 	"github.com/stretchr/testify/require"
 
 	"github.com/hashicorp/consul/agent/cache"
@@ -7817,9 +7818,15 @@ func TestSanitize(t *testing.T) {
 			"DogstatsdTags": [],
 			"FilterDefault": false,
 			"MetricsPrefix": "",
-			"PrometheusRetentionTime": "0s",
 			"StatsdAddr": "",
-			"StatsiteAddr": ""
+			"StatsiteAddr": "",
+			"PrometheusOpts": {
+				"Expiration": "0s",
+				"Registerer": null,
+				"GaugeDefinitions": [],
+				"CounterDefinitions": [],
+				"SummaryDefinitions": []
+			}
 		},
 		"TranslateWANAddrs": false,
 		"TxnMaxReqLen": 5678000000000000,

lib/telemetry.go

@@ -220,6 +220,10 @@ func (c *TelemetryConfig) MergeDefaults(defaults *TelemetryConfig) {
 		// implementing this for the types we actually have for now. Test failure
 		// should catch the case where we add new types later.
 		switch f.Kind() {
+		case reflect.Struct:
+			if f.Type() == reflect.TypeOf(prometheus.PrometheusOpts{}) {
+				continue
+			}
 		case reflect.Slice:
 			if !f.IsNil() {
 				continue
@@ -281,13 +285,7 @@ func prometheusSink(cfg TelemetryConfig, hostname string) (metrics.MetricSink, e
 		return nil, nil
 	}
 
-	prometheusOpts := prometheus.PrometheusOpts{
-		Expiration:         cfg.PrometheusOpts.Expiration,
-		GaugeDefinitions:   cfg.PrometheusOpts.GaugeDefinitions,
-		CounterDefinitions: cfg.PrometheusOpts.CounterDefinitions,
-		SummaryDefinitions: cfg.PrometheusOpts.SummaryDefinitions,
-	}
-	sink, err := prometheus.NewPrometheusSinkFrom(prometheusOpts)
+	sink, err := prometheus.NewPrometheusSinkFrom(cfg.PrometheusOpts)
 	if err != nil {
 		return nil, err
 	}

lib/telemetry_test.go

@@ -5,11 +5,14 @@ import (
 	"testing"
 	"time"
 
+	"github.com/armon/go-metrics/prometheus"
+
 	"github.com/stretchr/testify/require"
 )
 
 func makeFullTelemetryConfig(t *testing.T) TelemetryConfig {
 	var (
+		promOpts    = prometheus.PrometheusOpts{}
 		strSliceVal = []string{"foo"}
 		strVal      = "foo"
 		intVal      = int64(1 * time.Second)
@@ -27,6 +30,12 @@ func makeFullTelemetryConfig(t *testing.T) TelemetryConfig {
 		// now for brevity but will fail the test if a new field type is added since
 		// this is likely not implemented in MergeDefaults either.
 		switch f.Kind() {
+		case reflect.Struct:
+			if f.Type() != reflect.TypeOf(promOpts) {
+				t.Fatalf("unknown struct type in TelemetryConfig: actual %v, expected: %v", f.Type(), reflect.TypeOf(promOpts))
+			}
+			// TODO(kit): This should delve into the fields and set them individually rather than using an empty struct
+			f.Set(reflect.ValueOf(promOpts))
 		case reflect.Slice:
 			if f.Type() != reflect.TypeOf(strSliceVal) {
 				t.Fatalf("unknown slice type in TelemetryConfig." +