ros2_medkit_topic_beacon

Gateway discovery plugin that subscribes to ROS 2 topics for real-time entity metadata. Enables push-based beacon discovery where nodes publish MedkitDiscoveryHint messages to enrich the SOVD entity tree.

How It Works

1. Nodes publish ros2_medkit_msgs::msg::MedkitDiscoveryHint messages on a beacon topic
2. The plugin subscribes, validates hints, and stores them with stamp-based TTL
3. A token bucket rate limiter prevents overload from high-frequency publishers
4. Results are exposed at the x-medkit-topic-beacon vendor extension endpoint

Hints transition through states: active (within TTL) -> stale (TTL expired, data still served with stale marker) -> expired (removed from store).

Configuration

plugins: ["topic_beacon"]
plugins.topic_beacon.path: "/path/to/libros2_medkit_topic_beacon.so"
plugins.topic_beacon.beacon_ttl_sec: 10.0
plugins.topic_beacon.beacon_expiry_sec: 300.0
plugins.topic_beacon.allow_new_entities: true
plugins.topic_beacon.max_messages_per_second: 100.0

See discovery options for full configuration reference.

When to Use

Use the topic beacon when entity metadata changes in real time - sensor health, connection quality, load metrics. For stable metadata that rarely changes, use the parameter beacon instead.

License

Apache License 2.0

Changelog for package ros2_medkit_topic_beacon

0.4.0 (2026-03-20)

• Initial release - topic-based beacon discovery plugin
• TopicBeaconPlugin with push-based topic subscription for entity enrichment
• x-medkit-topic-beacon vendor extension REST endpoint
• Stamp-based TTL for topic beacon hints
• Diagnostic logging for beacon hint processing
• Contributors: \@bburda