contrib/google.golang.org/grpc.v12: replace missing {From,New}Context…

… with equivalent functions (#2624)

.github/workflows/unit-integration-tests.yml

@@ -245,18 +245,26 @@ jobs:
       - name: Testing outlier gRPC v1.2
         run: |
               # This hacky approach is necessary because running the tests regularly
-              # do not allow using [email protected] alongside [email protected]
+              # do not allow using [email protected] alongside [email protected].
+              # [email protected] is no longer possible to test because internal/datastreams/propagator.go
+              # expects sketches-go to have the package `github.com/DataDog/sketches-go/ddsketch/encoding` which
+              # is only present from v1.1.0 onwards.
               go mod vendor
 
               # Checkout [email protected]
               cd vendor/google.golang.org && rm -rf grpc
               git clone https://github.com/grpc/grpc-go grpc && cd grpc
-              git fetch origin && git checkout v1.2.0 && cd ../..
+              git fetch origin && git checkout v1.2.0 && cd ../../..
 
-              # Checkout sketches-go@v1.0.0
+              # Checkout sketches-go@v1.1.0
               cd vendor/github.com/DataDog && rm -rf sketches-go
               git clone https://github.com/DataDog/sketches-go && cd sketches-go
-              git fetch origin && git checkout v1.0.0 && cd ../..
+              git fetch origin && git checkout v1.1.0 && cd ../../../..
+
+              # Revert to old metadata functions as FromIncomingContext and NewOutgoingContext are not present in v1.2.0.
+              # These functions were updated to current versions to avoid compilation errors in the development environments.
+              sed  -i 's/metadata\.FromIncomingContext/metadata.FromContext/g' ./contrib/google.golang.org/grpc.v12/*
+              sed  -i 's/metadata\.NewOutgoingContext/metadata.NewContext/g' ./contrib/google.golang.org/grpc.v12/*
 
               go test -mod=vendor -v ./contrib/google.golang.org/grpc.v12/...
 

contrib/google.golang.org/grpc.v12/grpc.go

@@ -75,7 +75,7 @@ func startServerSpanFromContext(ctx context.Context, method string, cfg *interce
 	// we will add the items in extraOpts
 	optsLocal := options.Copy(cfg.spanOpts...)
 	optsLocal = append(optsLocal, extraOpts...)
-	md, _ := metadata.FromContext(ctx) // nil is ok
+	md, _ := metadata.FromIncomingContext(ctx) // nil is ok
 	if sctx, err := tracer.Extract(grpcutil.MDCarrier(md)); err == nil {
 		optsLocal = append(optsLocal, tracer.ChildOf(sctx))
 	}
@@ -108,12 +108,12 @@ func UnaryClientInterceptor(opts ...InterceptorOption) grpc.UnaryClientIntercept
 			tracer.Tag(ext.GRPCFullMethod, method),
 		)
 		span, ctx = tracer.StartSpanFromContext(ctx, cfg.spanName, spanopts...)
-		md, ok := metadata.FromContext(ctx)
+		md, ok := metadata.FromIncomingContext(ctx)
 		if !ok {
 			md = metadata.MD{}
 		}
 		_ = tracer.Inject(span.Context(), grpcutil.MDCarrier(md))
-		ctx = metadata.NewContext(ctx, md)
+		ctx = metadata.NewOutgoingContext(ctx, md)
 		opts = append(opts, grpc.Peer(&p))
 		err := invoker(ctx, method, req, reply, cc, opts...)
 		if p.Addr != nil {