The art of simplicity

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:

When creating your gRPC implementation you have to be aware about the difference between Unary RPC and Streams. Unary RPC This is the simplest type of RPC, where the client sends a single request and gets back a single response. This is the simplest approach and similar to what we know when using WCF. Streams With streaming we have to make a difference between server streaming, client streaming and bidirectional streaming. A server-streaming RPC is most similar to the Unary RPC, the only difference is that the server sends back a stream of responses instead of a single response after getting the client’s request message. After sending back all its responses, the server’s status details (status code and optional status message) and optional trailing metadata are sent back to complete on the server side. The client completes once it has all the server’s responses. A client-streaming RPC turns things around, the client sends a stream of requests to the server instead of a ...