virt: assert network is ready in each node before starting workloads

Otherwise, we risk facing a situation where the primary UDN will not be
plumbed into the worlkload.

Signed-off-by: Miguel Duarte Barroso <mdbarroso@redhat.com>

test/extended/networking/livemigration.go

@@ -1,10 +1,12 @@
 package networking
 
 import (
+	"bufio"
 	"context"
 	"encoding/json"
 	"fmt"
 	"net"
+	"regexp"
 	"strings"
 	"time"
 
@@ -79,6 +81,15 @@ var _ = Describe("[sig-network][OCPFeatureGate:PersistentIPsForVirtualization][F
 
 						createNetworkFn(netConfig)
 
+						for _, node := range workerNodes {
+							Eventually(func() bool {
+								isNetProvisioned, err := isNetworkProvisioned(oc, node.Name, netConfig.networkName)
+								return err == nil && isNetProvisioned
+							}).WithPolling(time.Second).WithTimeout(udnCrReadyTimeout).Should(
+								BeTrueBecause("the network must be ready before creating workloads"),
+							)
+						}
+
 						httpServerPods := prepareHTTPServerPods(f, netConfig, workerNodes)
 						vmCreationParams := kubevirt.CreationTemplateParams{
 							VMName:                    vmName,
@@ -462,3 +473,70 @@ func checkEastWestTraffic(virtClient *kubevirt.Client, vmiName string, podIPsByN
 		}
 	}
 }
+
+func isNetworkProvisioned(oc *exutil.CLI, nodeName string, networkName string) (bool, error) {
+	var podName string
+	var out string
+	var err error
+
+	out, err = runOcWithRetry(oc.AsAdmin(), "get",
+		"pods",
+		"-o", "name",
+		"-n", "openshift-ovn-kubernetes",
+		"--field-selector", fmt.Sprintf("spec.nodeName=%s", nodeName),
+		"-l", "app=ovnkube-node")
+	if err != nil {
+		return false, err
+	}
+	outReader := bufio.NewScanner(strings.NewReader(out))
+	re := regexp.MustCompile("^pod/(.*)")
+	for outReader.Scan() {
+		match := re.FindSubmatch([]byte(outReader.Text()))
+		if len(match) != 2 {
+			continue
+		}
+		podName = string(match[1])
+		break
+	}
+	if podName == "" {
+		return false, fmt.Errorf("could not find a valid ovnkube-node pod on node '%s'", nodeName)
+	}
+
+	ovnkubePod, err := oc.AdminKubeClient().CoreV1().Pods("openshift-ovn-kubernetes").Get(context.Background(),
+		podName, metav1.GetOptions{})
+	if err != nil {
+		return false, fmt.Errorf("couldn't get %s pod in openshift-ovn-kubernetes namespace: %v", podName, err)
+	}
+
+	ovnkubeContainerName := ""
+	for _, container := range ovnkubePod.Spec.Containers {
+		if container.Name == "ovnkube-node" {
+			ovnkubeContainerName = container.Name
+		} else if container.Name == "ovnkube-controller" {
+			ovnkubeContainerName = container.Name
+		}
+	}
+	if ovnkubeContainerName == "" {
+		return false, fmt.Errorf("didn't find ovnkube-node or ovnkube-controller container in %s pod", podName)
+	}
+
+	lsName := logicalSwitchName(networkName)
+	out, err = adminExecInPod(
+		oc,
+		"openshift-ovn-kubernetes",
+		podName,
+		ovnkubeContainerName,
+		fmt.Sprintf("ovn-nbctl list logical-switch %s", lsName),
+	)
+	if err != nil {
+		return false, fmt.Errorf("failed to find a logical switch for network %q: %w", networkName, err)
+	}
+
+	return strings.Contains(out, lsName), nil
+}
+
+func logicalSwitchName(networkName string) string {
+	netName := strings.ReplaceAll(networkName, "-", ".")
+	netName = strings.ReplaceAll(netName, "/", ".")
+	return fmt.Sprintf("%s_ovn_layer2_switch", netName)
+}