Remove systemd service result file after configuration update

This is required to ensure that we will not read outdated result in
edge case scenarios, e.g. when systemd service exist but for some
reason was disabled by the user.

Signed-off-by: Yury Kulazhenkov <ykulazhenkov@nvidia.com>

pkg/daemon/daemon.go

@@ -583,13 +583,22 @@ func (dn *Daemon) nodeStateSyncHandler() error {
 	// or there is a new config we need to apply
 	// When using systemd configuration we write the file
 	if dn.useSystemdService {
-		r, err := systemd.WriteConfFile(latestState, dn.devMode, dn.platform)
+		systemdConfModified, err := systemd.WriteConfFile(latestState, dn.devMode, dn.platform)
 		if err != nil {
 			log.Log.Error(err, "nodeStateSyncHandler(): failed to write configuration file for systemd mode")
 			return err
 		}
-		reqDrain = reqDrain || r
-		reqReboot = reqReboot || r
+		if systemdConfModified {
+			// remove existing result file to make sure that we will not use outdated result, e.g. in case if
+			// systemd service was not triggered for some reason
+			err = systemd.RemoveSriovResult()
+			if err != nil {
+				log.Log.Error(err, "nodeStateSyncHandler(): failed to remove result file for systemd mode")
+				return err
+			}
+		}
+		reqDrain = reqDrain || systemdConfModified
+		reqReboot = reqReboot || systemdConfModified
 		log.Log.V(0).Info("nodeStateSyncHandler(): systemd mode WriteConfFile results",
 			"drain-required", reqDrain, "reboot-required", reqReboot, "disable-drain", dn.disableDrain)
 

pkg/systemd/systemd.go

@@ -209,6 +209,20 @@ func ReadSriovResult() (*SriovResult, error) {
 	return result, err
 }
 
+func RemoveSriovResult() error {
+	err := os.Remove(SriovHostSystemdResultPath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			log.Log.V(2).Info("RemoveSriovResult(): result file not found")
+			return nil
+		}
+		log.Log.Error(err, "RemoveSriovResult(): failed to remove sriov result file", "path", SriovHostSystemdResultPath)
+		return err
+	}
+	log.Log.V(2).Info("RemoveSriovResult(): result file removed")
+	return nil
+}
+
 func WriteSriovSupportedNics() error {
 	_, err := os.Stat(sriovHostSystemdSupportedNicPath)
 	if err != nil {