Don't trace gRPC "Canceled" errors

We were getting a *lot* of log chaff at TRACE level during normal
operation because gRPC returns a "context canceled" error periodically
but it's not really an error for us because we immediately loop around
again.

This commit uses the gRPC status.Code() method to identify these
non-errors. It also uses errors.Is() instead of == to compare error
objects. This handles wrapped errors.

https://pkg.go.dev/google.golang.org/grpc/status#Code

https://github.com/golang/go/wiki/ErrorValueFAQ#how-should-i-change-my-error-handling-code-to-work-with-the-new-features

Signed-off-by: Toby Cabot <[email protected]>

pkg/registry/core/trace/ns_registry.go

@@ -19,13 +19,16 @@ package trace
 
 import (
 	"context"
+	"errors"
 	"io"
 
 	"github.com/networkservicemesh/sdk/pkg/registry/core/streamcontext"
 	"github.com/networkservicemesh/sdk/pkg/tools/typeutils"
 
 	"github.com/golang/protobuf/ptypes/empty"
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
 
 	"github.com/networkservicemesh/api/pkg/api/registry"
 )
@@ -47,10 +50,10 @@ func (t *traceNetworkServiceRegistryFindClient) Recv() (*registry.NetworkService
 	rv, err := s.Recv()
 
 	if err != nil {
-		if err == io.EOF {
+		if errors.Is(err, io.EOF) {
 			return nil, err
 		}
-		if err == context.Canceled {
+		if status.Code(err) == codes.Canceled {
 			return nil, err
 		}
 		return nil, logError(ctx, err, operation)

pkg/registry/core/trace/nse_registry.go

@@ -18,13 +18,16 @@ package trace
 
 import (
 	"context"
+	"errors"
 	"io"
 
 	"github.com/networkservicemesh/sdk/pkg/registry/core/streamcontext"
 	"github.com/networkservicemesh/sdk/pkg/tools/typeutils"
 
 	"github.com/golang/protobuf/ptypes/empty"
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
 
 	"github.com/networkservicemesh/api/pkg/api/registry"
 )
@@ -47,10 +50,10 @@ func (t *traceNetworkServiceEndpointRegistryFindClient) Recv() (*registry.Networ
 	rv, err := s.Recv()
 
 	if err != nil {
-		if err == io.EOF {
+		if errors.Is(err, io.EOF) {
 			return nil, err
 		}
-		if err == context.Canceled {
+		if status.Code(err) == codes.Canceled {
 			return nil, err
 		}
 		return nil, logError(ctx, err, operation)