[plugins/k8s][feat] Make KubernetesService a load balancer (#1638)

plugins/k8s/resoto_plugin_k8s/resources.py

@@ -1044,11 +1044,12 @@ class KubernetesServiceSpec:
 
 
 @define(eq=False, slots=False)
-class KubernetesService(KubernetesResource):
+class KubernetesService(KubernetesResource, BaseLoadBalancer):
     kind: ClassVar[str] = "kubernetes_service"
     mapping: ClassVar[Dict[str, Bender]] = KubernetesResource.mapping | {
         "service_status": S("status") >> Bend(KubernetesServiceStatus.mapping),
         "service_spec": S("spec") >> Bend(KubernetesServiceSpec.mapping),
+        "public_ip_address": S("spec", "externalIPs", 0),
     }
     reference_kinds: ClassVar[ModelReference] = {
         "successors": {
@@ -1061,10 +1062,28 @@ class KubernetesService(KubernetesResource):
 
     def connect_in_graph(self, builder: GraphBuilder, source: Json) -> None:
         super().connect_in_graph(builder, source)
+        resolved_backends = set()
+
+        pods = [
+            ((key, val), pod)
+            for pod in builder.graph.nodes
+            if isinstance(pod, KubernetesPod)
+            for key, val in pod.labels.items()
+        ]
+        pods_by_labels = defaultdict(list)
+        for (key, val), pod in pods:
+            pods_by_labels[(key, val)].append(pod)
+
         selector = bend(S("spec", "selector"), source)
         if selector:
             builder.add_edges_from_selector(self, EdgeType.default, selector, KubernetesPod)
 
+            for key, value in selector.items():
+                for pod in pods_by_labels.get((key, value), []):
+                    resolved_backends.add(pod.name or pod.id)
+
+        self.backends = list(resolved_backends)
+
 
 # endregion
 

plugins/k8s/test/resources_test.py

@@ -105,7 +105,10 @@ def test_Ingress(json_file: Json) -> None:
 
 @pytest.mark.json_file("api_v1_services.json")
 def test_service(json_file: Json) -> None:
-    round_trip(KubernetesService, json_file)
+    services, _ = round_trip(KubernetesService, json_file)
+    service = services[0][0]
+    assert service.backends == []
+    assert service.public_ip_address == "198.51.100.32"
 
 
 @pytest.mark.json_file("apis_storage.k8s.io_v1_csidrivers.json")

resotolib/resotolib/json_bender.py

@@ -93,7 +93,7 @@ class S(Bender):
     Retrieve a value from a JSON object under given path.
     """
 
-    def __init__(self, *path: str, default: Optional[Any] = None):
+    def __init__(self, *path: Union[str, int], default: Optional[Any] = None):
         if not path:
             raise ValueError("No path given")
         self._path = path
@@ -104,7 +104,7 @@ def execute(self, source: Any) -> Any:
             for key in self._path:
                 source = source[key]
             return source
-        except (KeyError, TypeError):
+        except (KeyError, TypeError, IndexError):
             return self._default
 
 

resotolib/test/json_bender_test.py

@@ -80,3 +80,10 @@ def test_map_dict() -> None:
     assert bend(MapDict(value_bender=F(lambda x: x + 1)), src) == {"a": 2, "b": 3}
     assert bend(MapDict(key_bender=F(lambda x: x + "b")), src) == {"ab": 1, "bb": 2}
     assert bend(MapDict(key_bender=F(lambda x: x + "b"), value_bender=F(lambda x: x + 1)), src) == {"ab": 2, "bb": 3}
+
+
+def test_array_traversal() -> None:
+    src = [{"a": 1}]
+
+    assert bend(S(0, "a"), src) == 1
+    assert bend(S(42, "a"), src) is None