runtime: tracing: End root span at end of trace

The root span should exist the duration of the trace. Defer ending span
until the end of the trace instead of end of function. Add the span to
the service struct to do so.

Fixes #4902

Signed-off-by: Chelsea Mafrica <chelsea.e.mafrica@intel.com>
(cherry picked from commit fcc1e0c617)

src/runtime/pkg/containerd-shim-v2/create.go

@@ -97,9 +97,10 @@ func create(ctx context.Context, s *service, r *taskAPI.CreateTaskRequest) (*con
 		}
 
 		// create root span
+		// rootSpan will be ended when the entire trace is ended
 		rootSpan, newCtx := katatrace.Trace(s.ctx, shimLog, "rootSpan", shimTracingTags)
 		s.rootCtx = newCtx
-		defer rootSpan.End()
+		s.rootSpan = rootSpan
 
 		// create span
 		span, newCtx := katatrace.Trace(s.rootCtx, shimLog, "create", shimTracingTags)

src/runtime/pkg/containerd-shim-v2/service.go

@@ -28,6 +28,7 @@ import (
 	"github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
+	otelTrace "go.opentelemetry.io/otel/trace"
 	"golang.org/x/sys/unix"
 
 	"github.com/kata-containers/kata-containers/src/runtime/pkg/katautils"
@@ -122,8 +123,9 @@ type exit struct {
 type service struct {
 	sandbox vc.VCSandbox
 
-	ctx     context.Context
-	rootCtx context.Context // root context for tracing
+	ctx      context.Context
+	rootCtx  context.Context // root context for tracing
+	rootSpan otelTrace.Span
 
 	containers map[string]*container
 
@@ -946,6 +948,7 @@ func (s *service) Shutdown(ctx context.Context, r *taskAPI.ShutdownRequest) (_ *
 		s.mu.Unlock()
 
 		span.End()
+		s.rootSpan.End()
 		katatrace.StopTracing(s.rootCtx)
 
 		return empty, nil