[backport/1.4] Fix Ping discovery KeyError on disappearing interfaces

core/services/ping/ping360_ethernet_prober.py

@@ -24,7 +24,7 @@ def list_ips() -> Set[str]:
     for interface in available_networks:
         ips.extend(
             phys.address
-            for phys in network_interface_addresses[interface]
+            for phys in network_interface_addresses.get(interface, [])
             if phys.family == socket.AF_INET and phys.address != "127.0.0.1"
         )
     return set(ips)  # make sure there are not duplicated entries

core/services/ping/setup.py

@@ -24,6 +24,7 @@
         "anyio == 3.7.1",
         "fastapi-versioning == 0.9.1",
         "loguru == 0.5.3",
+        "psutil == 5.7.2",
         "pyserial == 3.5",
         "starlette == 0.27.0",
         "uvicorn == 0.13.4",

core/services/ping/test_ping360_ethernet_prober.py

@@ -0,0 +1,47 @@
+import socket
+import sys
+from pathlib import Path
+from types import SimpleNamespace
+from unittest.mock import patch
+
+_PING_DIR = str(Path(__file__).resolve().parent)
+sys.path.insert(0, _PING_DIR)
+# Root pytest also finds other services' top-level modules (e.g. ardupilot_manager/exceptions.py).
+for _name in ("exceptions", "pingutils", "ping360_ethernet_prober", "portwatcher"):
+    _mod = sys.modules.get(_name)
+    if _mod is not None and not str(getattr(_mod, "__file__", "")).startswith(_PING_DIR):
+        del sys.modules[_name]
+
+import psutil
+
+import ping360_ethernet_prober
+
+
+def test_list_ips_ignores_interfaces_missing_from_address_snapshot() -> None:
+    stats = {
+        "eth0": SimpleNamespace(isup=True),
+        "lo": SimpleNamespace(isup=True),
+        "wlan0": SimpleNamespace(isup=False),
+        "noipv4": SimpleNamespace(isup=True),
+        "uap0": SimpleNamespace(isup=True),
+    }
+    addresses = {
+        "eth0": [SimpleNamespace(family=socket.AF_INET, address="192.168.2.2")],
+        "lo": [SimpleNamespace(family=socket.AF_INET, address="127.0.0.1")],
+        "wlan0": [SimpleNamespace(family=socket.AF_INET, address="192.168.10.2")],
+        "noipv4": [SimpleNamespace(family=socket.AF_INET6, address="::1")],
+    }
+
+    with (
+        patch.object(psutil, "net_if_stats", return_value=stats),
+        patch.object(psutil, "net_if_addrs", return_value=addresses),
+    ):
+        assert ping360_ethernet_prober.list_ips() == {"192.168.2.2"}
+
+
+def test_list_ips_returns_empty_set_for_empty_snapshots() -> None:
+    with (
+        patch.object(psutil, "net_if_stats", return_value={}),
+        patch.object(psutil, "net_if_addrs", return_value={}),
+    ):
+        assert ping360_ethernet_prober.list_ips() == set()

pyproject.toml

@@ -24,6 +24,7 @@ pytest = "7.4.2"
 coverage = "7.5.1"
 pytest-cov = "4.1.0"
 pydantic = "1.10.12"
+psutil = "5.7.2"
 docker = "6.1.3"
 aiodocker = "0.21.0"
 aiohttp = "3.9.5"