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ros2 node info Colorization

When you run ros2 node info /node_name, DendROS automatically colorizes the output using the same group colors configured for ros2 launch. No extra setup is required — colors are read from the same cache file the pipe writes during launch.

What it looks like

ros2 node info /costmap_builder

ros2 node info colorized output

What gets colored

Node name

The first line (the node name) is colored with the group color and badge — the same way it appears in ros2 launch output.

Section headers

All section headers (Subscribers:, Publishers:, Service Servers:, …) are rendered bold, regardless of whether a config is loaded.

Type annotations

The message or service type on each entry (: sensor_msgs/msg/LaserScan or [sensor_msgs/msg/LaserScan]) is dimmed on every line. (None) entries are also dimmed and receive no color.

Output sections

Entries in Publishers, Service Servers, and Action Servers are colored with the node's own group color — these are things the node provides to others.

Input sections

Entries in Subscribers, Service Clients, and Action Clients are colored with the provider's color — the color of whichever node publishes, serves, or handles that item:

Section Colored with
Subscribers Primary publisher's group color
Service Clients Service server node's group color
Action Clients Action server node's group color

Group indicators on topics

For Publishers and Subscribers, DendROS queries the live ROS 2 graph and shows small inverted-color count indicators at the end of each entry — one per distinct group with connected endpoints:

  • Publishers: indicators show how many subscribers are connected per group.
  • Subscribers: indicators show how many publishers are connected per group.
  Publishers:
    /costmap: std_msgs/msg/OccupancyGrid  [PLN]2 [MON]1
    /rosout: rcl_interfaces/msg/Log

The number inside each colored block is the count of nodes from that group connected to the topic. This gives you an immediate visual overview of who is listening to or publishing each topic.

For Service Clients and Action Clients with more than one matching server, extra server nodes are shown as trailing colored ■ squares after the type annotation.

Color and tag sources

DendROS uses the same two-stage lookup as ros2 node list:

  1. Primary — ~/.config/dendROS/node_colors.yaml (written automatically during any ros2 launch or ros2 run).
  2. Fallback — scans AMENT_PREFIX_PATH for installed dendROS.yaml configs.

If no config is found, section headers are still bolded and types dimmed, but no group colors are applied.

Notes

  • Both name: type (older ROS 2) and name [type] (newer ROS 2) entry formats are handled automatically.
  • Graph queries use a single rclpy session for all input sections (topics, services, and actions) to minimize overhead and avoid DDS discovery races.
  • When rclpy is unavailable, services and actions fall back to a name heuristic (/server_name/service → server_name); topics fall back to ros2 topic info --verbose subprocesses.