feat: replace pgcoordinator pg_notify triggers with app-level Publish() (#24717)

coderd/database/migrations/000483_drop_tailnet_notify_triggers.down.sql

@@ -0,0 +1,43 @@
+CREATE FUNCTION tailnet_notify_coordinator_heartbeat() RETURNS trigger
+    LANGUAGE plpgsql
+    AS $$
+BEGIN
+	PERFORM pg_notify('tailnet_coordinator_heartbeat', NEW.id::text);
+	RETURN NULL;
+END;
+$$;
+
+CREATE FUNCTION tailnet_notify_peer_change() RETURNS trigger
+    LANGUAGE plpgsql
+    AS $$
+BEGIN
+	IF (OLD IS NOT NULL) THEN
+		PERFORM pg_notify('tailnet_peer_update', OLD.id::text);
+		RETURN NULL;
+	END IF;
+	IF (NEW IS NOT NULL) THEN
+		PERFORM pg_notify('tailnet_peer_update', NEW.id::text);
+		RETURN NULL;
+	END IF;
+END;
+$$;
+
+CREATE FUNCTION tailnet_notify_tunnel_change() RETURNS trigger
+    LANGUAGE plpgsql
+    AS $$
+BEGIN
+	IF (NEW IS NOT NULL) THEN
+		PERFORM pg_notify('tailnet_tunnel_update', NEW.src_id || ',' || NEW.dst_id);
+		RETURN NULL;
+	ELSIF (OLD IS NOT NULL) THEN
+		PERFORM pg_notify('tailnet_tunnel_update', OLD.src_id || ',' || OLD.dst_id);
+		RETURN NULL;
+	END IF;
+END;
+$$;
+
+CREATE TRIGGER tailnet_notify_coordinator_heartbeat AFTER INSERT OR UPDATE ON tailnet_coordinators FOR EACH ROW EXECUTE FUNCTION tailnet_notify_coordinator_heartbeat();
+
+CREATE TRIGGER tailnet_notify_peer_change AFTER INSERT OR DELETE OR UPDATE ON tailnet_peers FOR EACH ROW EXECUTE FUNCTION tailnet_notify_peer_change();
+
+CREATE TRIGGER tailnet_notify_tunnel_change AFTER INSERT OR DELETE OR UPDATE ON tailnet_tunnels FOR EACH ROW EXECUTE FUNCTION tailnet_notify_tunnel_change();

coderd/database/migrations/000483_drop_tailnet_notify_triggers.up.sql

@@ -0,0 +1,6 @@
+DROP TRIGGER IF EXISTS tailnet_notify_peer_change ON tailnet_peers;
+DROP TRIGGER IF EXISTS tailnet_notify_tunnel_change ON tailnet_tunnels;
+DROP TRIGGER IF EXISTS tailnet_notify_coordinator_heartbeat ON tailnet_coordinators;
+DROP FUNCTION IF EXISTS tailnet_notify_peer_change();
+DROP FUNCTION IF EXISTS tailnet_notify_tunnel_change();
+DROP FUNCTION IF EXISTS tailnet_notify_coordinator_heartbeat();