Controller: handle add/remove in the same reconciliation

pkg/annotations/dynamic-network-status.go

@@ -3,10 +3,12 @@ package annotations
 import (
 	"encoding/json"
 	"fmt"
+	"strings"
 
 	corev1 "k8s.io/api/core/v1"
 
 	nettypes "github.com/k8snetworkplumbingwg/network-attachment-definition-client/pkg/apis/k8s.cni.cncf.io/v1"
+	v1 "github.com/k8snetworkplumbingwg/network-attachment-definition-client/pkg/apis/k8s.cni.cncf.io/v1"
 	nadutils "github.com/k8snetworkplumbingwg/network-attachment-definition-client/pkg/utils"
 )
 
@@ -64,6 +66,31 @@ func PodDynamicNetworkStatus(currentPod *corev1.Pod) ([]nettypes.NetworkStatus,
 	return currentIfaceStatus, nil
 }
 
+// SetNetworkStatus updates the Pod status
+func SetNetworkStatus(pod *corev1.Pod, statuses []v1.NetworkStatus) error {
+	if pod == nil {
+		return fmt.Errorf("no pod set")
+	}
+
+	var networkStatus []string
+
+	for _, status := range statuses {
+		data, err := json.MarshalIndent(status, "", "    ")
+		if err != nil {
+			return fmt.Errorf("SetNetworkStatus: error with Marshal Indent: %v", err)
+		}
+		networkStatus = append(networkStatus, string(data))
+	}
+
+	if len(pod.Annotations) == 0 {
+		pod.Annotations = make(map[string]string)
+	}
+
+	pod.Annotations[v1.NetworkStatusAnnot] = fmt.Sprintf("[%s]", strings.Join(networkStatus, ","))
+
+	return nil
+}
+
 func podNameAndNs(currentPod *corev1.Pod) string {
 	return fmt.Sprintf("%s/%s", currentPod.GetNamespace(), currentPod.GetName())
 }

pkg/controller/pod.go

@@ -248,6 +248,20 @@ func (pnc *PodNetworksController) processNextWorkItem() bool {
 		}
 	}
 
+	// handleDynamicInterfaceRequest modifies the pod annotation with the latest status
+	// so the updated status annotation can be obtained from there.
+	newIfaceStatus, err := annotations.PodDynamicNetworkStatus(pod)
+	if err != nil {
+		klog.Errorf("failed while getting network status annotation: %v", err)
+		return true
+	}
+
+	// apply the network status using the Kubernetes API.
+	if err := nadutils.SetNetworkStatus(pnc.k8sClientSet, pod, newIfaceStatus); err != nil {
+		klog.Errorf("failed while setting network status annotation: %v", err)
+		return true
+	}
+
 	return true
 }
 
@@ -346,8 +360,9 @@ func (pnc *PodNetworksController) addNetworks(dynamicAttachmentRequest *DynamicA
 		return fmt.Errorf("failed to compute the updated network status: %v", err)
 	}
 
-	if err := nadutils.SetNetworkStatus(pnc.k8sClientSet, pod, newIfaceStatus); err != nil {
-		return err
+	err = annotations.SetNetworkStatus(pod, newIfaceStatus)
+	if err != nil {
+		return fmt.Errorf("failed to set the network status annotation: %v", err)
 	}
 
 	return nil
@@ -404,8 +419,10 @@ func (pnc *PodNetworksController) removeNetworks(dynamicAttachmentRequest *Dynam
 			err,
 		)
 	}
-	if err := nadutils.SetNetworkStatus(pnc.k8sClientSet, pod, newIfaceStatus); err != nil {
-		return err
+
+	err = annotations.SetNetworkStatus(pod, newIfaceStatus)
+	if err != nil {
+		return fmt.Errorf("failed to set the network status annotation: %v", err)
 	}
 
 	return nil

pkg/controller/pod_test.go

@@ -301,6 +301,58 @@ var _ = Describe("Dynamic Attachment controller", func() {
 				})
 			})
 
+			When("an attachment is removed and another is added from the pod's network annotations", func() {
+				JustBeforeEach(func() {
+					pod = updatePodSpec(pod)
+					netSelectionElements := []nad.NetworkSelectionElement{
+						{
+							Name:             networkToAdd,
+							Namespace:        namespace,
+							InterfaceRequest: "net1",
+						},
+					}
+					serelizedNetSelectionElements, _ := json.Marshal(netSelectionElements)
+					pod.Annotations[nad.NetworkAttachmentAnnot] = string(serelizedNetSelectionElements)
+					var err error
+					_, err = k8sClient.CoreV1().Pods(namespace).UpdateStatus(
+						context.TODO(),
+						pod,
+						metav1.UpdateOptions{})
+					Expect(err).NotTo(HaveOccurred())
+				})
+
+				It("an `AddedInterface` event and then and `RemovedInterface` event are seen in the event recorded", func() {
+					expectedEventPayload := fmt.Sprintf(
+						"Normal AddedInterface pod [%s]: added interface %s to network: %s",
+						annotations.NamespacedName(namespace, podName),
+						"net1",
+						networkToAdd,
+					)
+					Eventually(<-eventRecorder.Events).Should(Equal(expectedEventPayload))
+					expectedEventPayload = fmt.Sprintf(
+						"Normal RemovedInterface pod [%s]: removed interface %s from network: %s",
+						annotations.NamespacedName(namespace, podName),
+						"net0",
+						networkName,
+					)
+					Eventually(<-eventRecorder.Events).Should(Equal(expectedEventPayload))
+				})
+
+				It("the pod network-status is updated with the new network attachment and without the other one", func() {
+					Eventually(func() ([]nad.NetworkStatus, error) {
+						updatedPod, err := k8sClient.CoreV1().Pods(namespace).Get(context.TODO(), podName, metav1.GetOptions{})
+						if err != nil {
+							return nil, err
+						}
+						status, err := annotations.PodDynamicNetworkStatus(updatedPod)
+						if err != nil {
+							return nil, err
+						}
+						return status, nil
+					}).Should(ConsistOf(ifaceStatusForDefaultNamespace(networkToAdd, "net1", macAddr)))
+				})
+			})
+
 		})
 	})
 })