Build a service, step by step

Eleven chapters grow one RustStream service, a small shop, from its first subscriber to a networked broker.

The shop takes an order, charges it, ships it and tells the customer. Each step is a subscriber, and the steps talk to each other through topics. The shop runs on the in-memory broker, so every chapter runs with nothing to install. Each chapter adds the components it needs and links to their pages in Components. Every code block has two tabs: Macros with the attributes and derives, Manual with the same code written by hand.

The finished shop lives in examples/guide in the repository, and its manual twin in examples/manual/guide. CI builds both and runs their tests on every change. Each side of the shop is a module: orders.rs, payments.rs, shipping.rs and notifications.rs. state.rs holds what the subscribers share, observability.rs a middleware of the shop's own, and service.rs assembles the app. main.rs is the command-line entry point, and http.rs runs the same shop beside an HTTP server.