httpserver: simplify WithMetrics usage.

httpserver/doc_test.go

@@ -3,6 +3,7 @@ package httpserver_test
 import (
 	"errors"
 	"github.com/clambin/go-common/httpserver"
+	"github.com/clambin/go-common/httpserver/middleware"
 	"github.com/prometheus/client_golang/prometheus"
 	"net/http"
 )
@@ -11,7 +12,7 @@ func Example() {
 	s, err := httpserver.New(
 		httpserver.WithAddr(":8080"),
 		httpserver.WithPrometheus(""),
-		httpserver.WithMetrics("", "", "example", httpserver.Summary, nil),
+		httpserver.WithMetrics(middleware.PrometheusMetricsOptions{Application: "example", MetricsType: middleware.Summary}),
 		httpserver.WithHandlers([]httpserver.Handler{{
 			Path:    "/",
 			Methods: []string{http.MethodGet},

httpserver/options.go

@@ -39,33 +39,8 @@ func WithHandlers(handlers []Handler) Option {
 }
 
 // WithMetrics will collect the specified metrics to instrument the Server's Handlers.
-func WithMetrics(namespace, subsystem, application string, metricsType MetricsType, buckets []float64) Option {
+func WithMetrics(metrics middleware.PrometheusMetricsOptions) Option {
 	return func(s *Server) {
-		// TODO: this is ugly is f*ck
-		mwOptions := middleware.PrometheusMetricsOptions{
-			Namespace:   namespace,
-			Subsystem:   subsystem,
-			Application: application,
-			Buckets:     buckets,
-		}
-		switch metricsType {
-		case Summary:
-			mwOptions.MetricsType = middleware.Summary
-		case Histogram:
-			mwOptions.MetricsType = middleware.Histogram
-		}
-		s.instrumentedHandler = middleware.NewPrometheusMetrics(mwOptions)
+		s.instrumentedHandler = middleware.NewPrometheusMetrics(metrics)
 	}
 }
-
-// MetricsType specifies the type of metrics to record for request duration. Use Summary if you are only interested in the average latency.
-// Use Histogram if you want to use a histogram to measure a service level indicator (eg  latency of 95% of all requests).
-type MetricsType int
-
-const (
-	// Summary measures the average duration.
-	Summary MetricsType = iota
-	// Histogram measures the latency in buckets and can be used to calculate a service level indicator. WithMetrics.Buckets
-	// specify the buckets to be used. If none are provided, prometheus.DefBuckets will be used.
-	Histogram
-)

httpserver/server_test.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"github.com/clambin/go-common/httpserver"
+	"github.com/clambin/go-common/httpserver/middleware"
 	"github.com/prometheus/client_golang/prometheus"
 	io_prometheus_client "github.com/prometheus/client_model/go"
 	"github.com/stretchr/testify/assert"
@@ -120,13 +121,13 @@ func TestServer_ServerHTTP_WithMetrics(t *testing.T) {
 	}{
 		{
 			name:         "histogram",
-			metrics:      httpserver.WithMetrics("", "", "foobar", httpserver.Histogram, nil),
+			metrics:      httpserver.WithMetrics(middleware.PrometheusMetricsOptions{Application: "foobar", MetricsType: middleware.Histogram}),
 			evalCount:    evalRequestsCounter,
 			evalDuration: evalDurationHistogram,
 		},
 		{
 			name:         "summary",
-			metrics:      httpserver.WithMetrics("", "", "foobar", httpserver.Summary, nil),
+			metrics:      httpserver.WithMetrics(middleware.PrometheusMetricsOptions{Application: "foobar", MetricsType: middleware.Summary}),
 			evalCount:    evalRequestsCounter,
 			evalDuration: evalDurationSummary,
 		},