RustFest2024 - Logging improvements suggestions

[DominikStefancik]

Why? What?

This draft PR contains suggestions on logging improvements discussed with the HULK team during RustFest 2024 in Zurich. It is supposed to serve as an inspiration for using logging in the hulk codebase.

We discussed two possible approaches:

1. Improve general logging
2. Use logging for tracing asynchronous communication between different parts of the robot system and debug tools.

Improve general logging

Current logging using fern crate could be enhanced by:

• using different "types" of logs for different purposes
• specifying logs with the target attribute and name of the crate (see changes in the path_planner.rs)
• define a separate config for these logs as well as their output (stdout, file, ...), (see change in the setup_logger function)

Use logging for tracing asynchronous communication

The idea is to use crate tracing for emitting log spans on one side and creating subscribers to these log on the other side.

For this you need to:

• add crates tracing and tracing-subscriber
• create a default or custom subscriber + define its configuration (see the changes in the tools/fanta/src/main.rs)
• emit log spans wherever you want to log details worth logging (see changes in the path_planner.rs)

Sources

Fern setup: example
Tracing used in Tokio: page

Possible next steps:

Create custom subscribers for a particular purpose: documentation
Use tokio-console for more logging, integrate with telemetry: documentation