Various fixes for issue #8

.gitignore

@@ -105,3 +105,11 @@ $RECYCLE.BIN/
 *.lnk
 
 # End of https://www.toptal.com/developers/gitignore/api/go,visualstudiocode,osx,linux,windows
+
+### Additional IDEs/Editors. ###
+/.idea/
+/*.iml
+
+/.vimrc
+*.swp
+*.tmp

inits.go

@@ -27,12 +27,13 @@ var now = time.Now()
 
 func startAPM(ctx context.Context, cfg *configs.Configs) *apm.APM {
 	ap, err := apm.New(ctx, &apm.Options{
-		Debug:            cfg.Environment == configs.EnvLocal,
-		Environment:      cfg.Environment.String(),
-		ServiceName:      cfg.AppName,
-		ServiceVersion:   cfg.AppVersion,
-		TracesSampleRate: 50.00,
-		UseStdOut:        cfg.Environment == configs.EnvLocal,
+		Debug:                cfg.Environment == configs.EnvLocal,
+		Environment:          cfg.Environment.String(),
+		ServiceName:          cfg.AppName,
+		ServiceVersion:       cfg.AppVersion,
+		PrometheusScrapePort: 9090,
+		TracesSampleRate:     50.00,
+		UseStdOut:            cfg.Environment == configs.EnvLocal,
 	})
 	if err != nil {
 		panic(errors.Wrap(err, "failed to start APM"))

internal/pkg/apm/apm.go

@@ -70,7 +70,7 @@ func New(ctx context.Context, opts *Options) (*APM, error) {
 	s.meterProvider = mProvider
 	SetGlobal(s)
 
-	return s, nil
+	return Global(), nil
 }
 
 // Shutdown gracefully switch off apm, flushing any data it have
@@ -140,9 +140,9 @@ func SetGlobal(apm *APM) {
 // Global gets global apm instance
 func Global() *APM {
 	if global == nil {
-		apm, _ := New(context.Background(), &Options{UseStdOut: false})
-		global = apm
-		return apm
+		message := "Attempt to use APM before it's been initialised."
+		fmt.Printf(message)
+		panic(message)
 	}
 	return global
 }
@@ -187,6 +187,10 @@ func newTracer(ctx context.Context, opts *Options) (trace.TracerProvider, *Trace
 
 	if opts.UseStdOut {
 		exporter, err = stdouttrace.New()
+	} else if opts.CollectorURL == "" {
+		fmt.Printf("Using no-op tracer as CollectorURL is not set.")
+		s.tracerProvider = nil
+		s.appTracer = nil
 	} else if httpCollector {
 		exporter, err = otlptracehttp.New(
 			ctx,

internal/pkg/apm/prometheus.go

@@ -28,20 +28,10 @@ func prometheusScraper(opts *Options) {
 		ReadHeaderTimeout: 5 * time.Second,
 	}
 
-	// logger.Info(
-	// 	"[otel/http] starting prometheus scrape endpoint",
-	// 	zap.String(
-	// 		"addr",
-	// 		fmt.Sprintf("localhost:%d/-/metrics", opts.PrometheusScrapePort),
-	// 	),
-	// )
+	fmt.Printf("[otel/http] starting prometheus metrics on :%d/-/metrics", opts.PrometheusScrapePort)
 	err := server.ListenAndServe()
 	if err != nil {
-		// logger.Error(
-		// 	"[otel/http] failed to serve metrics at:",
-		// 	zap.Error(err),
-		// 	zap.Uint16("port", opts.PrometheusScrapePort),
-		// )
-		return
+		fmt.Printf("[otel/http] failed to start prometheus metrics on :%d/-/metrics ; %+v", opts.PrometheusScrapePort, err)
+		panic(err)
 	}
 }

internal/pkg/sysignals/sysignals.go

@@ -20,7 +20,8 @@ func NotifyErrorOnQuit(errs chan<- error, otherSignals ...syscall.Signal) {
 
 	for signalType := range interrupt {
 		switch signalType {
-		case syscall.SIGINT, syscall.SIGTERM, syscall.SIGQUIT, syscall.SIGTSTP:
+		// syscall.SIGTSTP not supported on Windows.
+		case syscall.SIGINT, syscall.SIGTERM, syscall.SIGQUIT/*, syscall.SIGTSTP*/:
 			errs <- errors.Wrapf(ErrSigQuit, "%v", signalType)
 			return
 		}

main.go

@@ -74,6 +74,13 @@ func main() {
 		}),
 	)
 
+	ap := startAPM(ctx, cfgs)mesg
+	if ap == nil {
+		message := "Failed to start APM!"
+		fmt.Printf(message)
+		panic(message)
+	}
+
 	healthResponder, err := startHealthResponder(ctx, probestatus, fatalErr)
 	if err != nil {
 		panic(err)
@@ -93,7 +100,7 @@ func main() {
 		healthResponder,
 		hserver,
 		gserver,
-		startAPM(ctx, cfgs),
+		ap,
 	)
 	exitErr = <-fatalErr
 }