chore: respond to PR feedback

flipt-io · Apr 24, 2024 · 043fc7c · 043fc7c
1 parent aa2d99a
commit 043fc7c
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Showing 3 changed files with 17 additions and 26 deletions.
diff --git a/internal/cmd/grpc.go b/internal/cmd/grpc.go
@@ -42,8 +42,6 @@ import (
 	"go.flipt.io/flipt/internal/tracing"
 	"go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
 	"go.opentelemetry.io/otel"
-	metric "go.opentelemetry.io/otel/metric"
-	metricnoop "go.opentelemetry.io/otel/metric/noop"
 	metricsdk "go.opentelemetry.io/otel/sdk/metric"
 	tracesdk "go.opentelemetry.io/otel/sdk/trace"
 	"go.uber.org/zap"
@@ -154,9 +152,6 @@ func NewGRPCServer(
 
 	logger.Debug("store enabled", zap.Stringer("store", store))
 
-	// Default to a no-op OTEL meter provider
-	var meterProvider metric.MeterProvider = metricnoop.NewMeterProvider()
-
 	// Initialize metrics exporter if enabled
 	if cfg.Metrics.Enabled {
 		metricExp, metricExpShutdown, err := metrics.GetExporter(ctx, &cfg.Metrics)
@@ -166,14 +161,12 @@ func NewGRPCServer(
 
 		server.onShutdown(metricExpShutdown)
 
-		meterProvider = metricsdk.NewMeterProvider(metricsdk.WithReader(metricExp))
+		meterProvider := metricsdk.NewMeterProvider(metricsdk.WithReader(metricExp))
+		otel.SetMeterProvider(meterProvider)
+
 		logger.Debug("otel metrics enabled", zap.String("exporter", string(cfg.Metrics.Exporter)))
 	}
 
-	otel.SetMeterProvider(meterProvider)
-
-	metrics.Meter = meterProvider.Meter("github.com/flipt-io/flipt")
-
 	// Initialize tracingProvider regardless of configuration. No extraordinary resources
 	// are consumed, or goroutines initialized until a SpanProcessor is registered.
 	tracingProvider, err := tracing.NewProvider(ctx, info.Version, cfg.Tracing)

diff --git a/internal/config/metrics.go b/internal/config/metrics.go
@@ -18,7 +18,7 @@ const (
 type MetricsConfig struct {
 	Enabled  bool               `json:"enabled" mapstructure:"enabled" yaml:"enabled"`
 	Exporter MetricsExporter    `json:"exporter,omitempty" mapstructure:"exporter" yaml:"exporter,omitempty"`
-	OTLP     *OTLPMetricsConfig `json:"otlp,omitempty" mapstructure:"otlp" yaml:"otlp,omitempty"`
+	OTLP     *OTLPMetricsConfig `json:"otlp,omitempty" mapstructure:"otlp,omitempty" yaml:"otlp,omitempty"`
 }
 
 type OTLPMetricsConfig struct {

diff --git a/internal/metrics/metrics.go b/internal/metrics/metrics.go
@@ -7,6 +7,7 @@ import (
 	"sync"
 
 	"go.flipt.io/flipt/internal/config"
+	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc"
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp"
 	"go.opentelemetry.io/otel/exporters/prometheus"
@@ -15,16 +16,13 @@ import (
 	sdkmetric "go.opentelemetry.io/otel/sdk/metric"
 )
 
-// Meter is the default Flipt-wide otel metric Meter.
-var Meter metric.Meter
-
 func init() {
-	// If the global Meter is nil, create a new noop Meter.
-	// Useful for testing.
-	if Meter == nil {
-		meterProvider := metricnoop.NewMeterProvider()
-		Meter = meterProvider.Meter("github.com/flipt-io/flipt")
-	}
+	otel.SetMeterProvider(metricnoop.NewMeterProvider())
+}
+
+// This is memoized in the OTEL library to avoid creating multiple instances of the same exporter.
+func meter() metric.Meter {
+	return otel.Meter("github.com/flipt-io/flipt")
 }
 
 // MustInt64 returns an instrument provider based on the global Meter.
@@ -55,7 +53,7 @@ type mustInt64Meter struct{}
 
 // Counter creates an instrument for recording increasing values.
 func (m mustInt64Meter) Counter(name string, opts ...metric.Int64CounterOption) metric.Int64Counter {
-	counter, err := Meter.Int64Counter(name, opts...)
+	counter, err := meter().Int64Counter(name, opts...)
 	if err != nil {
 		panic(err)
 	}
@@ -65,7 +63,7 @@ func (m mustInt64Meter) Counter(name string, opts ...metric.Int64CounterOption)
 
 // UpDownCounter creates an instrument for recording changes of a value.
 func (m mustInt64Meter) UpDownCounter(name string, opts ...metric.Int64UpDownCounterOption) metric.Int64UpDownCounter {
-	counter, err := Meter.Int64UpDownCounter(name, opts...)
+	counter, err := meter().Int64UpDownCounter(name, opts...)
 	if err != nil {
 		panic(err)
 	}
@@ -75,7 +73,7 @@ func (m mustInt64Meter) UpDownCounter(name string, opts ...metric.Int64UpDownCou
 
 // Histogram creates an instrument for recording a distribution of values.
 func (m mustInt64Meter) Histogram(name string, opts ...metric.Int64HistogramOption) metric.Int64Histogram {
-	hist, err := Meter.Int64Histogram(name, opts...)
+	hist, err := meter().Int64Histogram(name, opts...)
 	if err != nil {
 		panic(err)
 	}
@@ -111,7 +109,7 @@ type mustFloat64Meter struct{}
 
 // Counter creates an instrument for recording increasing values.
 func (m mustFloat64Meter) Counter(name string, opts ...metric.Float64CounterOption) metric.Float64Counter {
-	counter, err := Meter.Float64Counter(name, opts...)
+	counter, err := meter().Float64Counter(name, opts...)
 	if err != nil {
 		panic(err)
 	}
@@ -121,7 +119,7 @@ func (m mustFloat64Meter) Counter(name string, opts ...metric.Float64CounterOpti
 
 // UpDownCounter creates an instrument for recording changes of a value.
 func (m mustFloat64Meter) UpDownCounter(name string, opts ...metric.Float64UpDownCounterOption) metric.Float64UpDownCounter {
-	counter, err := Meter.Float64UpDownCounter(name, opts...)
+	counter, err := meter().Float64UpDownCounter(name, opts...)
 	if err != nil {
 		panic(err)
 	}
@@ -131,7 +129,7 @@ func (m mustFloat64Meter) UpDownCounter(name string, opts ...metric.Float64UpDow
 
 // Histogram creates an instrument for recording a distribution of values.
 func (m mustFloat64Meter) Histogram(name string, opts ...metric.Float64HistogramOption) metric.Float64Histogram {
-	hist, err := Meter.Float64Histogram(name, opts...)
+	hist, err := meter().Float64Histogram(name, opts...)
 	if err != nil {
 		panic(err)
 	}