This chapter will cover using remote procedure calls (RPCs) in Rust. You'll need a working Rust compiler, because we will create two examples with the jsonrpc-http-server and grpc crates.
If you want to test TLS connections, you'll need OpenSSL version 0.9, because the grpc crate doesn't support version 1.0 or higher yet. Most modern operating systems have switched to 1.0 already, but you can build the examples to a Docker image that supports version 0.9, or wait till the grpc crate is updated to the latest OpenSSL version. We will build test examples without TLS.
You can find the sources of the examples from this chapter in the GitHub repository at, https://github.com/PacktPublishing/Hands-On-Microservices-with-Rust/tree/master/Chapter06.