README.md

Discovery Example README

This is the simplest DDS Enabler example and a good starting point. It launches a DDS Enabler that listens to the DDS network and prints the name of every topic, service and action it discovers - nothing else (no types, no QoS, no data).

The application keeps running until it is stopped with Ctrl+C.

It registers only the three discovery notification callbacks of the CallbackSet:

• dds.topic_notification → prints discovered topic names.
• service.service_notification → prints discovered service names.
• action.action_notification → prints discovered action names.

Compilation

The example is compiled together with the DDS Enabler when the project is built with the -DCOMPILE_EXAMPLES=ON CMake option. It can also be compiled standalone against an already installed DDS Enabler.

First, source the environment where the DDS Enabler is installed.

source <ddsenabler-installation-path>/install/setup.bash

Then configure and build the example from its own directory.

mkdir build
cd build
cmake ..
cmake --build .

The ddsenabler_example_discovery executable is generated inside the build directory.

Example Command

./ddsenabler_example_discovery config.yml

Run it and then start any DDS / ROS 2 application (for instance the ROS 2 talker, or another DDS Enabler example such as publish, service or action). When a topic, service, or action is discovered, the application prints a line like:

[Discovery] Topic discovered: rt/chatter
[Discovery] Service discovered: /add_two_ints
[Discovery] Action discovered: /fibonacci

Press Ctrl+C to stop the application cleanly.

An optional YAML configuration file may be passed as the first argument to customize the DDS behavior (domain, allow/deny topic lists, etc.). Without it, the Enabler uses its default configuration (DDS domain 0).