README.md

pg-notify

Dashboard + SSE feed for visualizing latency and rate metrics from PostgreSQL channels you LISTEN on.

Run Against Your Own Database

1. Make sure your database emits NOTIFY events.

   The app listens on PostgreSQL channels and expects JSON payloads with a created_at field formatted as RFC3339 or RFC3339Nano.

   Example trigger function:

   CREATE OR REPLACE FUNCTION notify_row_change()
   RETURNS trigger
   LANGUAGE plpgsql
   AS $$
   DECLARE
     ts timestamptz;
   BEGIN
     ts := COALESCE(NEW.created_at, OLD.created_at, NOW());
   
     PERFORM pg_notify(
       'channel_name',
       json_build_object(
         'created_at',
         to_char(ts, 'YYYY-MM-DD"T"HH24:MI:SS.USOF')
       )::text
     );
   
     RETURN COALESCE(NEW, OLD);
   END;
   $$;

   Attach it to a table:

   CREATE TRIGGER my_table_notify_trigger
   AFTER INSERT OR UPDATE OR DELETE ON my_table
   FOR EACH ROW
   EXECUTE FUNCTION notify_row_change();

2. Create a pg-notify.cfg.

   {
     "database_url": "postgres://user:pass@your-host:5432/your_db?sslmode=require",
     "port": 8080,
     "event_names": ["channel_name", "channel_name2"]
   }

3. Run the service.

   go run .

   Or build it first:

   go build
   ./pg-notify

4. Open the dashboard.

   Visit:

   http://localhost:<port>
   

Demo

For demoing the repository includes a small Postgres image and helper scripts in db/.

Follow db/README.md to build and run the container, then run:

make demo

This starts the app and pushes synthetic activity into the demo database.