[Otel] SpanProcessor panic on shutdown with background context

[Duong Cong Toai]

Summary

I setup sentry with Opentelemetry, and on shutdown, the code panic with stack trace

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x10 pc=0xa700f7]

goroutine 7211 [running]:
github.com/getsentry/sentry-go.(*Hub).stackTop(0xc000126000?)
	/go/pkg/mod/github.com/getsentry/sentry-go@v0.22.0/hub.go:109 +0x37
github.com/getsentry/sentry-go.(*Hub).Client(0x4a139c?)
	/go/pkg/mod/github.com/getsentry/sentry-go@v0.22.0/hub.go:136 +0x19
github.com/getsentry/sentry-go.(*Hub).Flush(0x47ab01?, 0xc0008cad50?)
	/go/pkg/mod/github.com/getsentry/sentry-go@v0.22.0/hub.go:347 +0x1e
github.com/getsentry/sentry-go/otel.flushSpanProcessor({0x146b420?, 0xc000d04b10?})
	/go/pkg/mod/github.com/getsentry/sentry-go/otel@v0.22.0/span_processor.go:108 +0x9a
github.com/getsentry/sentry-go/otel.(*sentrySpanProcessor).ForceFlush(...)
	/go/pkg/mod/github.com/getsentry/sentry-go/otel@v0.22.0/span_processor.go:101
github.com/getsentry/sentry-go/otel.(*sentrySpanProcessor).Shutdown(0x101eee0?, {0x146b420, 0xc000d04b10})
	/go/pkg/mod/github.com/getsentry/sentry-go/otel@v0.22.0/span_processor.go:96 +0x39
go.opentelemetry.io/otel/sdk/trace.(*TracerProvider).Shutdown.func1()
	/go/pkg/mod/go.opentelemetry.io/otel/sdk@v1.13.0/trace/provider.go:259 +0x39
sync.(*Once).doSlow(0xc00058ae80?, 0x4064f1?)
	/usr/local/go/src/sync/once.go:74 +0xc2
sync.(*Once).Do(...)
	/usr/local/go/src/sync/once.go:65
go.opentelemetry.io/otel/sdk/trace.(*TracerProvider).Shutdown(0xc000192600, {0x146b420, 0xc000d04b10})
	/go/pkg/mod/go.opentelemetry.io/otel/sdk@v1.13.0/trace/provider.go:258 +0x285

How i init client

	batchProcessor := sdktrace.NewBatchSpanProcessor(exporter)
	sampler := sdktrace.ParentBased(sdktrace.TraceIDRatioBased(opts.SampleRate))
	propagator := propagation.NewCompositeTextMapPropagator(
		propagation.TraceContext{},
		b3.New(b3.WithInjectEncoding(b3.B3SingleHeader|b3.B3MultipleHeader)), // For Istio compatibility
	)
	tp := sdktrace.NewTracerProvider(
		sdktrace.WithSampler(sampler),
		sdktrace.WithSpanProcessor(batchProcessor),
		sdktrace.WithResource(resource.NewWithAttributes(
			semconv.SchemaURL,
			semconv.ServiceNameKey.String(opts.TracerName),
			semconv.ServiceVersionKey.String(opts.TracerVersion),
			attribute.String(environmentLabel, opts.Environment),
		)),
	)
	
        tp.RegisterSpanProcessor(sentryotel.NewSentrySpanProcessor())
	
	otel.SetTracerProvider(tp)
	otel.SetTextMapPropagator(propagator)

How i shutdown (ctx is background)

			if tp, ok := tp.(*sdktrace.TracerProvider); ok && tp != nil {
				return tp.Shutdown(ctx)
			}

This code panic because in the context there is no hub assigned, and the spanprocessor try to call stackTop on a nil hub, do i have to explicitly assign a hub into the main context?

Environment

SDK

• sentry-go version: 0.22.0
• Go version: 1.20
• Using Go Modules? [yes]

Additional context

[Anton Ovchinnikov]

Thanks for reporting, we'll look into it.