Hello ROS community! 
Following the REP-0001:2025 process, I’m opening this discussion thread for Draft REP 0156:2026: ROS Log Command Line Interface.
We are seeking community feedback on this REP, so please feel free to share your thoughts and opinion here.
Quick Links
- Draft REP: ROS Log Command Line Interface | Robotics Enhancement Proposals (merged)
- Initial PR: https://github.com/openrobotics/reps/pull/20
- Related Issue: `ros2log` new 1st class command group support · Issue #1148 · ros2/ros2cli · GitHub
Abstract
This REP proposes a new ros2log command-line package for ROS that provides a unified, user-friendly interface for runtime logging configuration and inspection.
Motivation
Currently, logging configuration from the command line in ROS 2 is limited or inconsistent. There is no central dedicated CLI for logging operations, which leads to:
- Scattered approaches (ad-hoc subcommands or raw service calls)
- Error-prone workflows requiring manual service calls
- Poor discoverability for logging-related features
As ROS 2 logging is crucial for debugging and production diagnostics, users need a clear and ergonomic CLI to interact with it.
Proposed Functionality
The REP proposes introducing a new ros2 log CLI command group with the following subcommands:
| Subcommand | Description |
|---|---|
ros2 log list |
List nodes that support runtime log configuration |
ros2 log levels |
Show all valid log level values (DEBUG, INFO, WARN, ERROR, FATAL) |
ros2 log get <node> |
Retrieve the current log level of a node |
ros2 log set <node> <level> |
Set the log level of a node |
ros2 log watch |
Tail/monitor logs from nodes via rosout |
ros2 log describe <node> |
Display metadata (available loggers, effective levels) |
Previous Discussions
This proposal builds on previous community discussions:
- Add verb for setting a node’s log level (ros2cli#1060)
- List loggers of a node (ros2#1762)
- External logging level configuration (ros2#1355)
- Command to monitor and pretty print the rosout logs (ros2cli#849)
Looking forward to your feedback! 
This discussion thread follows REP-0001:2025 Step 4. Substantial discussion should happen in this public topic to ensure all interested people can participate.