Fix goroutine leaks in otlptracegrpc testing (#2409)

* Fail in RunEndToEndTest if collector stop fails

* Use testing T.Cleanup to check shut downs

* Add goroutine leak detection

* Fix TestExporterShutdown go leak

The shutdown tests checking if a context error is honored did not
completely clean up the resources used by the client after the error was
evaluated. Update the connection client to handle multiple calls to
shutdown and make a second call to these clients that must succeed so
the test does not have abandoned goroutines.

* Fix leak in TestNew_WithTimeout

The mockTraceService did not delay with its lock being held. This
resulted in the mockCollector stopping and being able to acquire the
lock. It was assumed that no export was taking place because of this and
the mockTraceService was abandoned without cleaning up resources it held
and goroutines it had spawned. This reworks the export blocking logic to
block on a channel read. This will make the block more deterministic and
not depend on the scheduler timing. Additionally, this blocking is moved
inside the lock acquire. Meaning code will deadlock if the block is not
released before a shutdown (something the developer will immediately be
aware of when they submit a bad patch), and will ensure all resources
are released before shutdown.

Replace TestNew_WithTimeout with TestExportSpansTimeoutHonored which
directly tests if a span export errors when the timeout is reached. This
is the only unique thing that TestNew_WithTimeout, but it also tests the
non-error path. That non-error path is tested in many other tests.

* Guard otlptracehttp client stopCh when stopping

In normal operations the exporter is guaranteed to only ever call the
client Stop method once. However in testing we need to call this
multiple times when checking it returns an error in particular context.
Add a lightweight sync.Once to the closing of the stopCh to ensure tests
do not panic when cleaning up.

* Release export block after export

Prevent deadlock in TestExportSpansTimeoutHonored.

example/otel-collector/go.sum

@@ -49,6 +49,11 @@ github.com/google/go-cmp v0.5.6/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/
 github.com/google/uuid v1.1.2/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/grpc-ecosystem/grpc-gateway v1.16.0 h1:gmcG1KaJ57LophUzW0Hy8NmPhnMZb4M0+kPpLofRdBo=
 github.com/grpc-ecosystem/grpc-gateway v1.16.0/go.mod h1:BDjrQk3hbvj6Nolgz8mAMFbcEtjT1g+wF4CSlocrBnw=
+github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
+github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
@@ -57,41 +62,63 @@ github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/yuin/goldmark v1.3.5/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
 go.opentelemetry.io/proto/otlp v0.7.0/go.mod h1:PqfVotwruBrMGOCsRd/89rSnXhoiJIqeYNgFYFoEGnI=
 go.opentelemetry.io/proto/otlp v0.11.0 h1:cLDgIBTf4lLOlztkhzAEdQsJ4Lj+i5Wc9k6Nn0K1VyU=
 go.opentelemetry.io/proto/otlp v0.11.0/go.mod h1:QpEjXPrNQzrFDZgoTo49dgHR9RYRSrg3NAKnUGl9YpQ=
+go.uber.org/goleak v1.1.12 h1:gZAh5/EyT/HQwlpkCy6wTpqfH9H8Lz8zbm3dZh+OyzA=
+go.uber.org/goleak v1.1.12/go.mod h1:cwTWslyiVhfpKIDGSZEM2HlOvcqm+tG4zioyIeLoqMQ=
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+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
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+golang.org/x/tools v0.1.5 h1:ouewzE6p+/VEB31YYnTbEJdi8pFqKp4P4n85vwo3DHA=
+golang.org/x/tools v0.1.5/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
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@@ -123,8 +150,9 @@ google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp0
 google.golang.org/protobuf v1.26.0/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
 google.golang.org/protobuf v1.27.1 h1:SnqbnDw1V7RiZcXPx5MEeqPv2s79L9i7BJUlG/+RurQ=
 google.golang.org/protobuf v1.27.1/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.3/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=

exporters/otlp/otlptrace/internal/connection/connection.go

@@ -53,6 +53,7 @@ type Connection struct {
 	disconnectedCh             chan bool
 	backgroundConnectionDoneCh chan struct{}
 	stopCh                     chan struct{}
+	stopOnce                   sync.Once
 
 	// this is for tests, so they can replace the closing
 	// routine without a worry of modifying some global variable
@@ -253,7 +254,9 @@ func (c *Connection) ContextWithMetadata(ctx context.Context) context.Context {
 }
 
 func (c *Connection) Shutdown(ctx context.Context) error {
-	close(c.stopCh)
+	c.stopOnce.Do(func() {
+		close(c.stopCh)
+	})
 	// Ensure that the backgroundConnector returns
 	select {
 	case <-c.backgroundConnectionDoneCh:

exporters/otlp/otlptrace/internal/otlptracetest/client.go

@@ -55,44 +55,58 @@ func initializeExporter(t *testing.T, client otlptrace.Client) *otlptrace.Export
 }
 
 func testClientStopHonorsTimeout(t *testing.T, client otlptrace.Client) {
+	t.Cleanup(func() {
+		// The test is looking for a failed shut down. Make sure the client is
+		// actually closed at the end thought to clean up any used resources.
+		if err := client.Stop(context.Background()); err != nil {
+			t.Fatalf("failed to stop client: %v", err)
+		}
+	})
 	e := initializeExporter(t, client)
 
-	innerCtx, innerCancel := context.WithTimeout(context.Background(), time.Microsecond)
-	<-innerCtx.Done()
-	if err := e.Shutdown(innerCtx); err == nil {
-		t.Error("expected context DeadlineExceeded error, got nil")
-	} else if !errors.Is(err, context.DeadlineExceeded) {
+	ctx, cancel := context.WithTimeout(context.Background(), time.Nanosecond)
+	defer cancel()
+	<-ctx.Done()
+
+	if err := e.Shutdown(ctx); !errors.Is(err, context.DeadlineExceeded) {
 		t.Errorf("expected context DeadlineExceeded error, got %v", err)
 	}
-	innerCancel()
 }
 
 func testClientStopHonorsCancel(t *testing.T, client otlptrace.Client) {
+	t.Cleanup(func() {
+		// The test is looking for a failed shut down. Make sure the client is
+		// actually closed at the end thought to clean up any used resources.
+		if err := client.Stop(context.Background()); err != nil {
+			t.Fatalf("failed to stop client: %v", err)
+		}
+	})
 	e := initializeExporter(t, client)
 
-	ctx, innerCancel := context.WithCancel(context.Background())
-	innerCancel()
-	if err := e.Shutdown(ctx); err == nil {
-		t.Error("expected context canceled error, got nil")
-	} else if !errors.Is(err, context.Canceled) {
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+
+	if err := e.Shutdown(ctx); !errors.Is(err, context.Canceled) {
 		t.Errorf("expected context canceled error, got %v", err)
 	}
 }
 
 func testClientStopNoError(t *testing.T, client otlptrace.Client) {
+	e := initializeExporter(t, client)
+
 	ctx, cancel := context.WithTimeout(context.Background(), 1*time.Minute)
 	defer cancel()
 
-	e := initializeExporter(t, client)
 	if err := e.Shutdown(ctx); err != nil {
 		t.Errorf("shutdown errored: expected nil, got %v", err)
 	}
 }
 
 func testClientStopManyTimes(t *testing.T, client otlptrace.Client) {
+	e := initializeExporter(t, client)
+
 	ctx, cancel := context.WithTimeout(context.Background(), 1*time.Minute)
 	defer cancel()
-	e := initializeExporter(t, client)
 
 	ch := make(chan struct{})
 	wg := sync.WaitGroup{}
@@ -110,7 +124,8 @@ func testClientStopManyTimes(t *testing.T, client otlptrace.Client) {
 	wg.Wait()
 	for _, err := range errs {
 		if err != nil {
-			t.Fatalf("failed to shutdown exporter: %v", err)
+			t.Errorf("failed to shutdown exporter: %v", err)
+			return
 		}
 	}
 }

exporters/otlp/otlptrace/internal/otlptracetest/otlptest.go

@@ -87,7 +87,9 @@ func RunEndToEndTest(ctx context.Context, t *testing.T, exp *otlptrace.Exporter,
 
 	// Shutdown the collector too so that we can begin
 	// verification checks of expected data back.
-	_ = tracesCollector.Stop()
+	if err := tracesCollector.Stop(); err != nil {
+		t.Fatalf("failed to stop the mock collector: %v", err)
+	}
 
 	// Now verify that we only got two resources
 	rss := tracesCollector.GetResourceSpans()