gRPC is a really great fit as a communication protocol between your (internal) microservices. It runs on top of HTTP/2 and gives you great performance.
One caveat is that the HTTP/2 prerequisite requires by default that all communication is happening securely. So you have to setup TLS and create certificates for all your services.
But what should you do when you are using Kubernetes and use TLS termination at the ingress controller level?
A new feature announced in .NET Core 3.0 brings rescue. You can turn on unencrypted connections for HTTP/2 by setting the DOTNET_SYSTEM_NET_HTTP_SOCKETSHTTPHANDLER_HTTP2UNENCRYPTEDSUPPORT environment variable to 1 or by enabling it in the app context: