Add check DNS operator

Author: weliang1

pkg/monitortests/network/legacynetworkmonitortests/networking.go

@@ -51,7 +51,6 @@ func getPlatformType(clientConfig *rest.Config) (configv1.PlatformType, error) {
 }
 
 func testPodSandboxCreation(events monitorapi.Intervals, clientConfig *rest.Config) []*junitapi.JUnitTestCase {
-	// This test is looking for the "FailedCreatePodSandBox" event which is generated by the kubelet when a pod cannot be started.
 	const testName = "[sig-network] pods should successfully create sandboxes"
 	// we can further refine this signal by subdividing different failure modes if it is pertinent.  Right now I'm seeing
 	// 1. error reading container (probably exited) json message: EOF
@@ -81,7 +80,8 @@ func testPodSandboxCreation(events monitorapi.Intervals, clientConfig *rest.Conf
 		}
 		isNetwork := ev.Locator.Keys[monitorapi.LocatorClusterOperatorKey] == "network"
 		isMCO := ev.Locator.Keys[monitorapi.LocatorClusterOperatorKey] == "machine-config"
-		if isNetwork || isMCO {
+		isDNS := ev.Locator.Keys[monitorapi.LocatorClusterOperatorKey] == "dns"
+		if isNetwork || isMCO || isDNS {
 			return true
 		}
 		return false