grpc: Use constants for metadata keys

grpc/client.go

@@ -73,13 +73,13 @@ func dialCtx(ctx context.Context, addr string) (*grpc.ClientConn, error) {
 
 func prepareClientContext(ctx context.Context) context.Context {
 	if loc, ok := locale.FromCtx(ctx); ok {
-		ctx = metadata.AppendToOutgoingContext(ctx, "locale", loc.Serialize())
+		ctx = metadata.AppendToOutgoingContext(ctx, MetadataKeyLocale, loc.Serialize())
 	}
 	if token, ok := security.GetTokenFromContext(ctx); ok {
-		ctx = metadata.AppendToOutgoingContext(ctx, "bearer_token", token.GetValue())
+		ctx = metadata.AppendToOutgoingContext(ctx, MetadataKeyBearerToken, token.GetValue())
 	}
 	if reqID := log.RequestIDFromContext(ctx); reqID != "" {
-		ctx = metadata.AppendToOutgoingContext(ctx, "req_id", reqID)
+		ctx = metadata.AppendToOutgoingContext(ctx, MetadataKeyRequestID, reqID)
 	}
 	ctx = EncodeContextWithUTMData(ctx)
 

grpc/consts.go

@@ -1,5 +1,9 @@
 package grpc
 
 const (
+	MetadataKeyBearerToken          = "bearer_token"
+	MetadataKeyContentType          = "content-type"
 	MetadataKeyExternalDependencies = "external_dependencies"
+	MetadataKeyLocale               = "locale"
+	MetadataKeyRequestID            = "req_id"
 )

grpc/server.go

@@ -152,7 +152,7 @@ func prepareContext(ctx context.Context) (context.Context, metadata.MD) {
 
 	// add request context if req_id is given
 	var reqID xid.ID
-	if ri := md.Get("req_id"); len(ri) > 0 {
+	if ri := md.Get(MetadataKeyRequestID); len(ri) > 0 {
 		var err error
 		reqID, err = xid.FromString(ri[0])
 		if err != nil {
@@ -175,7 +175,7 @@ func prepareContext(ctx context.Context) (context.Context, metadata.MD) {
 	})
 
 	// handle locale
-	if l := md.Get("locale"); len(l) > 0 {
+	if l := md.Get(MetadataKeyLocale); len(l) > 0 {
 		loc, err := locale.ParseLocale(l[0])
 		if err != nil {
 			log.Ctx(ctx).Debug().Err(err).Msgf("unable to parse locale: %v", err)
@@ -187,7 +187,7 @@ func prepareContext(ctx context.Context) (context.Context, metadata.MD) {
 	ctx = ContextWithUTMFromMetadata(ctx, md)
 
 	// add security context if bearer token is given
-	if bt := md.Get("bearer_token"); len(bt) > 0 {
+	if bt := md.Get(MetadataKeyBearerToken); len(bt) > 0 {
 		ctx = security.ContextWithToken(ctx, security.TokenString(bt[0]))
 	}
 
@@ -198,10 +198,10 @@ func prepareContext(ctx context.Context) (context.Context, metadata.MD) {
 		ctx = middleware.ContextWithExternalDependency(ctx, &externalDependencyContext)
 	}
 
-	delete(md, "content-type")
-	delete(md, "locale")
-	delete(md, "bearer_token")
-	delete(md, "req_id")
+	delete(md, MetadataKeyContentType)
+	delete(md, MetadataKeyLocale)
+	delete(md, MetadataKeyBearerToken)
+	delete(md, MetadataKeyRequestID)
 	delete(md, MetadataKeyExternalDependencies)
 
 	return ctx, md