Introduction

zbus is a Rust crate for D-Bus. If you are not familiar with D-Bus, you should read what is D-Bus? first¹. In short, zbus allows you to communicate from one program to another, using the D-Bus protocol. In other words, it’s an inter-process communication (IPC) solution. It is a very popular IPC solution on Linux and many Linux services (e.g systemd, NetworkManager) and desktop environments (e.g GNOME and KDE), rely on D-Bus for their IPC needs. There are many tools and implementations available, making it easy to interact with D-Bus programs from different languages and environments.

zbus is a 100% Rust-native implementation of the D-Bus protocol. It provides both an API to send and receive messages over a connection, as well as API to interact with peers through high-level concepts like method calls, signals and properties². Thanks to the power of Rust macros, zbus is able to make interacting with D-Bus very easy.

The crate has two halves.

The wire format

D-Bus defines a marshalling format for its messages. The zbus::wire module provides a serde-based API to serialize and deserialize Rust data types to and from that format. It does not need the rest of zbus, so if the format is all you are after — no connection, no proxies — depend on zbus with its default features disabled:

[dependencies]
zbus = { version = "6", default-features = false }

Outside of a D-Bus context, a modified form of this format, GVariant, is commonly used for efficient storage of arbitrary data; the separate zgvariant crate implements it.

The D-Bus API

Everything else — connections, messages, proxies, the object server — is the API you will use to interact with D-Bus from Rust. It takes care of the establishment of a connection, the creation, sending and receiving of different kind of D-Bus messages (method calls, signals etc) for you.

The API is async. A program with no async runtime of its own drives it with zbus::block_on, which runs a future to completion on the calling thread; the FAQ shows how.

1. D-Bus is ~15y old, unfortunately many documents out there are sometime aging or misleading. ↩

2. These concepts are explained in the following chapter. ↩