Function Prometheus

app/controlplane/internal/usercontext/wrappers.go:32–55

This package contains a set of wrappers that take grpc.UnaryInterceptors and translate them into Kratos middlewares. The reason for having these kind of wrappers is so we can sort them in the context of the rest of middlewares. Otherwise, plain grpc interceptors will be added after the chain of midd

()

// Otherwise, plain grpc interceptors will be added after the chain of middlewares
// https://github.com/go-kratos/kratos/blob/f8b97f675b32dfad02edae12d83053c720720b5b/transport/grpc/server.go#L166
func Prometheus() middleware.Middleware {
	var interceptor = grpc_prometheus.UnaryServerInterceptor
	return func(handler middleware.Handler) middleware.Handler {
		return func(ctx context.Context, req interface{}) (interface{}, error) {
			// Extract gRPC metadata from the context
			info, ok := transport.FromServerContext(ctx)
			if !ok {
				// If gRPC metadata is not available, fallback to default handler
				return handler(ctx, req)
			}

			// Wrap the handler into a gRPC UnaryHandler
			grpcHandler := func(ctx context.Context, req interface{}) (interface{}, error) {
				return handler(ctx, req)
			}

			// Call the interceptor
			return interceptor(ctx, req, &grpc.UnaryServerInfo{
				Server:     nil, // Kratos doesn't provide the server instance directly
				FullMethod: info.Operation(),
			}, grpcHandler)
		}
	}
}