fix(#18): implement shutdown for tracer and meter

.mockery.yaml

@@ -0,0 +1,12 @@
+with-expecter: true
+disable-version-string: true
+inpackage: false
+mockname: "{{.InterfaceName}}"
+filename: "{{.InterfaceNameSnake}}.go"
+outpkg: "mocks"
+dir: "{{.InterfaceDirRelative}}/mocks"
+
+packages:
+  "flamingo.me/opentelemetry":
+    interfaces:
+      Shutdowner:

Readme.md

@@ -47,18 +47,18 @@ Flamingo's `URLPrefixSampler` and config from `flamingo.opencensus.tracing.sampl
 Before you can create your own spans, you have to initialize a tracer:
 
 ```go
-tracer := otel.Tracer("my-app")
+var tracer = otel.Tracer("my-app", trace.WithInstrumentationVersion("1.2.3"))
 ```
 
 Now you can create a span based on a `context.Context`. This will automatically attach all tracing-relevant
 information (e.g. trace-ID) to the span.
 
 ```go
 func doSomething(ctx context.Context) {
-ctx, span := tracer.Start(ctx, "my-span")
-defer span.End()
-
-// do some work to track with my-span	
+	ctx, span := tracer.Start(ctx, "my-span")
+	defer span.End() 
+	
+	// do some work to track with my-span
 }
 ```
 
@@ -70,14 +70,15 @@ official [OpenTelemetry documentation](https://opentelemetry.io/docs/instrumenta
 To collect your own metrics, you have to initialize a meter:
 
 ```go
-meter := otel.Meter("my-app")
+var meter = otel.Meter("my-app", metric.WithInstrumentationVersion("1.2.3"))
 ```
 
 Now you can create a new metric, e.g. a counter:
 
 ```go
-counter, _ := meter.Int64Counter("my.count",
-metric.WithDescription("count of something"),
+counter, _ := meter.Int64Counter("my.count", 
+	metric.WithDescription("count of something"),
+	metric.WithUnit("{something}")
 )
 
 counter.Add(ctx, 1)

go.mod

@@ -52,6 +52,7 @@ require (
 	github.com/redis/go-redis/v9 v9.6.1 // indirect
 	github.com/spf13/cobra v1.8.1 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
+	github.com/stretchr/objx v0.5.2 // indirect
 	github.com/zemirco/memorystore v0.0.0-20160308183530-ecd57e5134f6 // indirect
 	go.opencensus.io v0.24.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.30.0 // indirect

go.sum

@@ -34,8 +34,6 @@ github.com/envoyproxy/go-control-plane v0.9.0/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymF
 github.com/envoyproxy/go-control-plane v0.9.1-0.20191026205805-5f8ba28d4473/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.4/go.mod h1:6rpuAdCZL397s3pYoYcLgu1mIlRU8Am5FuJP05cCM98=
 github.com/envoyproxy/protoc-gen-validate v0.1.0/go.mod h1:iSmxcyjqTsJpI2R4NaDN7+kN2VEUnK/pcBlmesArF7c=
-github.com/felixge/httpsnoop v1.0.3 h1:s/nj+GCswXYzN5v2DpNMuMQYe+0DDwt5WVCU6CWBdXk=
-github.com/felixge/httpsnoop v1.0.3/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
 github.com/felixge/httpsnoop v1.0.4 h1:NFTV2Zj1bL4mc9sqWACXbQFVBBg2W3GPvqp8/ESS2Wg=
 github.com/felixge/httpsnoop v1.0.4/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
 github.com/ghodss/yaml v1.0.0 h1:wQHKEahhL6wmXdzwWG11gIVCkOv05bNOh+Rxn0yngAk=
@@ -133,6 +131,8 @@ github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
 github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
+github.com/stretchr/objx v0.5.2 h1:xuMeJ0Sdp5ZMRXx/aWO6RZxdr3beISkG5/G/aIRr3pY=
+github.com/stretchr/objx v0.5.2/go.mod h1:FRsXN1f5AsAjCGJKqEizvkpNtU+EGNCLh3NxZ/8L+MA=
 github.com/stretchr/testify v1.2.0/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
@@ -143,18 +143,12 @@ github.com/zemirco/memorystore v0.0.0-20160308183530-ecd57e5134f6 h1:j+ZgVPhfLkC
 github.com/zemirco/memorystore v0.0.0-20160308183530-ecd57e5134f6/go.mod h1:PLhuixMlky6sB4/LEnpp1//u2BcRF2pKUYXLMVyOrIc=
 go.opencensus.io v0.24.0 h1:y73uSU6J157QMP2kn2r30vwW1A2W2WFwSCGnAVxeaD0=
 go.opencensus.io v0.24.0/go.mod h1:vNK8G9p7aAivkbmorf4v+7Hgx+Zs0yY+0fOtgBfjQKo=
-go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.45.0 h1:x8Z78aZx8cOF0+Kkazoc7lwUNMGy0LrzEMxTm4BbTxg=
-go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.45.0/go.mod h1:62CPTSry9QZtOaSsE3tOzhx6LzDhHnXJ6xHeMNNiM6Q=
 go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.54.0 h1:TT4fX+nBOA/+LUkobKGW1ydGcn+G3vRw9+g5HwCphpk=
 go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.54.0/go.mod h1:L7UH0GbB0p47T4Rri3uHjbpCFYrVrwc1I25QhNPiGK8=
-go.opentelemetry.io/contrib/instrumentation/runtime v0.45.0 h1:2JydY5UiDpqvj2p7sO9bgHuhTy4hgTZ0ymehdq/Ob0Q=
-go.opentelemetry.io/contrib/instrumentation/runtime v0.45.0/go.mod h1:ch3a5QxOqVWxas4CzjCFFOOQe+7HgAXC/N1oVxS9DK4=
 go.opentelemetry.io/contrib/instrumentation/runtime v0.54.0 h1:KD+8SJvRaW9n0vE0UgkytT207J3CmV1hGf9GYYU73ns=
 go.opentelemetry.io/contrib/instrumentation/runtime v0.54.0/go.mod h1:/CsTuLR28IN3Vn13YEc72HljfHiGOMXiCbl4xiCSDhA=
 go.opentelemetry.io/otel v1.30.0 h1:F2t8sK4qf1fAmY9ua4ohFS/K+FUuOPemHUIXHtktrts=
 go.opentelemetry.io/otel v1.30.0/go.mod h1:tFw4Br9b7fOS+uEao81PJjVMjW/5fvNCbpsDIXqP0pc=
-go.opentelemetry.io/otel/bridge/opencensus v0.45.0 h1:kEOlv9Exuv3J8GCf1nLMHfrTPGnZOuIkN8YlRM14TtQ=
-go.opentelemetry.io/otel/bridge/opencensus v0.45.0/go.mod h1:tkVMJeFOr43+zzwbxtIWsNcCCDT7rI5/c9rhMfMIENg=
 go.opentelemetry.io/otel/bridge/opencensus v1.30.0 h1:F6WsF4aSV6g6IBiK4NZ8gWNHqFjtwxrEsUnrYEGyBSw=
 go.opentelemetry.io/otel/bridge/opencensus v1.30.0/go.mod h1:3FOD7DbLQhWLxwnzbYoT1oHucvoQIqLXHez1u2KIxMc=
 go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.30.0 h1:lsInsfvhVIfOI6qHVyysXMNDnjO9Npvl7tlDPJFBVd4=

module.go

@@ -1,5 +1,7 @@
 package opentelemetry
 
+//go:generate go run github.com/vektra/mockery/v2@v2.45.1
+
 import (
 	"context"
 	"fmt"
@@ -69,6 +71,8 @@ func (m *Module) Inject(
 func (m *Module) Configure(injector *dingo.Injector) {
 	http.DefaultTransport = &correlationIDInjector{next: otelhttp.NewTransport(http.DefaultTransport)}
 
+	flamingo.BindEventSubscriber(injector).To(new(Listener))
+
 	m.initTraces()
 	m.initMetrics(injector)
 }

module_test.go

@@ -0,0 +1,28 @@
+package opentelemetry_test
+
+import (
+	"testing"
+
+	"flamingo.me/dingo"
+	"flamingo.me/flamingo/v3/framework/config"
+	"flamingo.me/flamingo/v3/framework/flamingo"
+
+	"flamingo.me/opentelemetry"
+)
+
+type (
+	loggerModule struct{}
+)
+
+// Configure DI
+func (m *loggerModule) Configure(injector *dingo.Injector) {
+	injector.Bind(new(flamingo.Logger)).To(new(flamingo.NullLogger))
+}
+
+func TestModule_Configure(t *testing.T) {
+	t.Parallel()
+
+	if err := config.TryModules(nil, new(loggerModule), new(opentelemetry.Module)); err != nil {
+		t.Error(err)
+	}
+}

shutdown.go

@@ -0,0 +1,56 @@
+package opentelemetry
+
+import (
+	"context"
+
+	"flamingo.me/flamingo/v3/framework/flamingo"
+	"go.opentelemetry.io/otel"
+)
+
+type (
+	Shutdowner interface {
+		Shutdown(ctx context.Context) error
+	}
+
+	Listener struct {
+		logger flamingo.Logger
+	}
+)
+
+// Inject dependencies
+func (l *Listener) Inject(
+	logger flamingo.Logger,
+) *Listener {
+	l.logger = logger
+
+	return l
+}
+
+func (l *Listener) Notify(ctx context.Context, event flamingo.Event) {
+	if _, ok := event.(*flamingo.ShutdownEvent); ok {
+		tp := otel.GetTracerProvider()
+		if s, ok := tp.(Shutdowner); ok {
+			l.shutdown(ctx, s)
+		}
+
+		mp := otel.GetMeterProvider()
+		if s, ok := mp.(Shutdowner); ok {
+			l.shutdown(ctx, s)
+		}
+	}
+}
+
+func (l *Listener) shutdown(ctx context.Context, s Shutdowner) {
+	l.log().Debugf("Shutdown OpenTelemetry: %T", s)
+
+	err := s.Shutdown(ctx)
+	if err != nil {
+		l.log().Error("", err)
+	}
+}
+
+func (l *Listener) log() flamingo.Logger {
+	return l.logger.
+		WithField(flamingo.LogKeyModule, "opentelemetry").
+		WithField(flamingo.LogKeyCategory, "Shutdown")
+}

shutdown_test.go

@@ -0,0 +1,77 @@
+package opentelemetry_test
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"flamingo.me/flamingo/v3/framework/flamingo"
+	"go.opentelemetry.io/otel"
+	noopMetric "go.opentelemetry.io/otel/metric/noop"
+	noopTrace "go.opentelemetry.io/otel/trace/noop"
+
+	"flamingo.me/opentelemetry"
+	"flamingo.me/opentelemetry/mocks"
+)
+
+type (
+	tracerProvider struct {
+		noopTrace.TracerProvider
+		mocks.Shutdowner
+	}
+
+	meterProvider struct {
+		noopMetric.MeterProvider
+		mocks.Shutdowner
+	}
+)
+
+var errShutdown = errors.New("shutdown error")
+
+func TestListener_Notify(t *testing.T) { //nolint:tparallel // no parallel subtests possible because of global state manipulation
+	t.Parallel()
+
+	type args struct {
+		event flamingo.Event
+	}
+
+	tests := []struct {
+		name               string
+		args               args
+		traceShutdownError error
+		meterShutdownError error
+	}{
+		{
+			name: "shutdown meter and tracer successfully",
+			args: args{
+				event: new(flamingo.ShutdownEvent),
+			},
+			traceShutdownError: nil,
+			meterShutdownError: nil,
+		},
+		{
+			name: "error on shutdown meter and tracer",
+			args: args{
+				event: new(flamingo.ShutdownEvent),
+			},
+			traceShutdownError: errShutdown,
+			meterShutdownError: errShutdown,
+		},
+	}
+
+	for _, tt := range tests { //nolint:paralleltest // no parallel test possible because of global state manipulation
+		t.Run(tt.name, func(t *testing.T) {
+			tp := new(tracerProvider)
+			tp.Shutdowner.EXPECT().Shutdown(context.Background()).Once().Return(tt.traceShutdownError)
+			otel.SetTracerProvider(tp)
+
+			mp := new(meterProvider)
+			mp.Shutdowner.EXPECT().Shutdown(context.Background()).Once().Return(tt.meterShutdownError)
+			otel.SetMeterProvider(mp)
+
+			l := new(opentelemetry.Listener).Inject(new(flamingo.NullLogger))
+
+			l.Notify(context.Background(), tt.args.event)
+		})
+	}
+}