Fix named ports of restartable init containers don't propagate to EndpointSlice

Author: toVersus

staging/src/k8s.io/endpointslice/utils.go

@@ -392,6 +392,17 @@ func findPort(pod *v1.Pod, svcPort *v1.ServicePort) (int, error) {
 				}
 			}
 		}
+		// also support sidecar container (initContainer with restartPolicy=Always)
+		for _, container := range pod.Spec.InitContainers {
+			if container.RestartPolicy == nil || *container.RestartPolicy != v1.ContainerRestartPolicyAlways {
+				continue
+			}
+			for _, port := range container.Ports {
+				if port.Name == name && port.Protocol == svcPort.Protocol {
+					return int(port.ContainerPort), nil
+				}
+			}
+		}
 	case intstr.Int:
 		return portName.IntValue(), nil
 	}

staging/src/k8s.io/endpointslice/utils_test.go

@@ -515,6 +515,7 @@ func TestServiceControllerKey(t *testing.T) {
 
 func TestGetEndpointPorts(t *testing.T) {
 	protoTCP := v1.ProtocolTCP
+	restartPolicyAlways := v1.ContainerRestartPolicyAlways
 
 	testCases := map[string]struct {
 		service       *v1.Service
@@ -585,6 +586,51 @@ func TestGetEndpointPorts(t *testing.T) {
 				AppProtocol: pointer.String("https"),
 			}},
 		},
+		"service with named port for restartable init container": {
+			service: &v1.Service{
+				Spec: v1.ServiceSpec{
+					Ports: []v1.ServicePort{{
+						Name:       "http-sidecar",
+						Port:       8080,
+						TargetPort: intstr.FromInt32(8080),
+						Protocol:   protoTCP,
+					}, {
+						Name:       "http",
+						Port:       8090,
+						TargetPort: intstr.FromString("http"),
+						Protocol:   protoTCP,
+					}},
+				},
+			},
+			pod: &v1.Pod{
+				Spec: v1.PodSpec{
+					InitContainers: []v1.Container{{
+						Ports: []v1.ContainerPort{{
+							Name:          "http-sidecar",
+							ContainerPort: int32(8080),
+							Protocol:      protoTCP,
+						}},
+						RestartPolicy: &restartPolicyAlways,
+					}},
+					Containers: []v1.Container{{
+						Ports: []v1.ContainerPort{{
+							Name:          "http",
+							ContainerPort: int32(8090),
+							Protocol:      protoTCP,
+						}},
+					}},
+				},
+			},
+			expectedPorts: []*discovery.EndpointPort{{
+				Name:     pointer.String("http-sidecar"),
+				Port:     pointer.Int32(8080),
+				Protocol: &protoTCP,
+			}, {
+				Name:     pointer.String("http"),
+				Port:     pointer.Int32(8090),
+				Protocol: &protoTCP,
+			}},
+		},
 	}
 
 	for name, tc := range testCases {