trace: make gRPC propagation compatible with Endpoints
We need to follow up the gRPC propagation proposal to bless
a gRPC key to be used all across Google products for compatibility.
Until then, use "x-cloud-trace-context".
Fixes
@@ -23,7 +23,7 @@ import (
"google.golang.org/grpc/metadata"
)
-const grpcMetadataKey = "stackdriver-trace-context"
+const grpcMetadataKey = "x-cloud-trace-context"
// GRPCClientInterceptor returns a grpc.UnaryClientInterceptor that traces all outgoing requests from a gRPC client.
// The calling context should already have a *trace.Span; a child span will be
