fix: log OBP RELAX_CHECKS target sync at debug, once per stream

src/adn_server/infrastructure/twisted_adapters/udp_hbp.py

@@ -247,6 +247,7 @@ class HBPProtocol(DatagramProtocol):
             # cleaned uniformly. No pre-seed of slot keys here.
             self.STATUS: dict[Any, Any] = {}
             self._bcsq_log_once: deque = deque(maxlen=1024)
+            self._obp_target_sync_log_once: deque = deque(maxlen=1024)
         else:
             self._laststrid = {1: b"", 2: b""}
             self.STATUS = {1: _make_slot_status(), 2: _make_slot_status()}
@@ -2109,9 +2110,14 @@ class HBPProtocol(DatagramProtocol):
         else:
             logger.debug("(%s) *BridgeControl* not sending BCVE, TARGET not currently known", self._system)
 
-    def _obp_sync_target_sock_from_peer(self, _sockaddr: tuple[str, int]) -> None:
+    def _obp_sync_target_sock_from_peer(self, _sockaddr: tuple[str, int], _stream_id: bytes | None = None) -> None:
         """If RELAX_CHECKS accepted traffic from a different IP:port than TARGET_SOCK, sync (same idea as BCKA).
-        Ensures BCSQ and outbound DMR go to the peer address we actually receive from."""
+        Ensures BCSQ and outbound DMR go to the peer address we actually receive from.
+
+        A peer behind per-packet load-balanced NAT can flip source address on every frame of the
+        same call, so the sync itself still runs every packet but the log is debug and capped to
+        once per stream_id (same _log_once deque idiom as _bcsq_log_once above).
+        """
         if self._config.get("MODE") != "OPENBRIDGE" or not self._config.get("RELAX_CHECKS"):
             return
         if not _sockaddr or not _sockaddr[0]:
@@ -2120,14 +2126,18 @@ class HBPProtocol(DatagramProtocol):
         if cur == _sockaddr:
             return
         h, p = _sockaddr[0], int(_sockaddr[1])
-        logger.info(
-            "(%s) *BridgeControl* OBP peer address sync to %s:%s (RELAX_CHECKS; was %s:%s)",
-            self._system,
-            h,
-            p,
-            (cur[0] if cur and cur[0] else "?"),
-            (cur[1] if cur and len(cur) > 1 else "?"),
-        )
+        _once = getattr(self, "_obp_target_sync_log_once", None)
+        if _stream_id is None or not isinstance(_once, deque) or _stream_id not in _once:
+            logger.debug(
+                "(%s) *BridgeControl* OBP peer address sync to %s:%s (RELAX_CHECKS; was %s:%s)",
+                self._system,
+                h,
+                p,
+                (cur[0] if cur and cur[0] else "?"),
+                (cur[1] if cur and len(cur) > 1 else "?"),
+            )
+            if _stream_id is not None and isinstance(_once, deque):
+                _once.append(_stream_id)
         self._config["TARGET_IP"] = h
         self._config["TARGET_PORT"] = p
         self._config["TARGET_SOCK"] = (h, p)
@@ -2166,7 +2176,7 @@ class HBPProtocol(DatagramProtocol):
             _ingress = self._try_decode_mesh_ingress(_packet)
             if _ingress is not None and _ingress.codec == "obp_v1" and (_sockaddr == self._config.get("TARGET_SOCK") or self._config.get("RELAX_CHECKS")):
                 _data = _ingress.voice_frame
-                self._obp_sync_target_sock_from_peer(_sockaddr)
+                self._obp_sync_target_sock_from_peer(_sockaddr, _stream_id)
                 _peer_id = _data[11:15]
                 if self._config.get("NETWORK_ID") != _peer_id:
                     if _stream_id not in self._laststrid:
@@ -2294,7 +2304,7 @@ class HBPProtocol(DatagramProtocol):
             _trailer = parse_dmre_trailer(_packet)
             _timestamp = _trailer.timestamp if _trailer is not None else b"\x00" * 8
             _stream_id = _data[16:20]
-            self._obp_sync_target_sock_from_peer(_sockaddr)
+            self._obp_sync_target_sock_from_peer(_sockaddr, _stream_id)
             _peer_id = _data[11:15]
             if self._config.get("NETWORK_ID") != _peer_id:
                 if _stream_id not in self._laststrid:

tests/infrastructure/test_obp_relax_checks_sync_log.py

@@ -0,0 +1,57 @@
+# ADN DMR Peer Server - OBP RELAX_CHECKS target-address sync log is debug, once per stream
+
+from __future__ import annotations
+
+import logging
+from collections import deque
+from types import SimpleNamespace
+
+from adn_server.infrastructure.twisted_adapters.udp_hbp import HBPProtocol
+
+_SYNC = HBPProtocol._obp_sync_target_sock_from_peer
+
+
+def _fake_obp(target_sock=None) -> SimpleNamespace:
+    return SimpleNamespace(
+        _system="OBP-USA",
+        _config={"MODE": "OPENBRIDGE", "RELAX_CHECKS": True, "TARGET_SOCK": target_sock},
+        _obp_target_sync_log_once=deque(maxlen=1024),
+    )
+
+
+def test_sync_updates_target_sock_every_packet() -> None:
+    fake = _fake_obp(target_sock=("1.1.1.1", 62044))
+    _SYNC(fake, ("2.2.2.2", 62044), b"strm")
+    assert fake._config["TARGET_SOCK"] == ("2.2.2.2", 62044)
+    _SYNC(fake, ("1.1.1.1", 62044), b"strm")
+    assert fake._config["TARGET_SOCK"] == ("1.1.1.1", 62044)
+
+
+def test_sync_logs_debug_once_per_stream_even_when_flapping(caplog) -> None:
+    fake = _fake_obp(target_sock=("1.1.1.1", 62044))
+    with caplog.at_level(logging.DEBUG, logger="adn_server.infrastructure.twisted_adapters.udp_hbp"):
+        for _ in range(20):
+            _SYNC(fake, ("2.2.2.2", 62044), b"strm-1")
+            _SYNC(fake, ("1.1.1.1", 62044), b"strm-1")
+    sync_records = [r for r in caplog.records if "OBP peer address sync" in r.message]
+    assert len(sync_records) == 1
+    assert sync_records[0].levelno == logging.DEBUG
+    # still tracked the address on every flap despite logging once
+    assert fake._config["TARGET_SOCK"] == ("1.1.1.1", 62044)
+
+
+def test_sync_logs_again_for_a_new_stream(caplog) -> None:
+    fake = _fake_obp(target_sock=("1.1.1.1", 62044))
+    with caplog.at_level(logging.DEBUG, logger="adn_server.infrastructure.twisted_adapters.udp_hbp"):
+        _SYNC(fake, ("2.2.2.2", 62044), b"strm-1")
+        _SYNC(fake, ("1.1.1.1", 62044), b"strm-1")
+        _SYNC(fake, ("2.2.2.2", 62044), b"strm-2")
+    sync_records = [r for r in caplog.records if "OBP peer address sync" in r.message]
+    assert len(sync_records) == 2
+
+
+def test_no_relax_checks_no_sync() -> None:
+    fake = _fake_obp(target_sock=("1.1.1.1", 62044))
+    fake._config["RELAX_CHECKS"] = False
+    _SYNC(fake, ("2.2.2.2", 62044), b"strm")
+    assert fake._config["TARGET_SOCK"] == ("1.1.1.1", 62044)