Add libvirt-exporter relabel rule

Change-Id: I7236682d40e1f0989cdf1b873a87b95df639844d
Related-bug: PROD-26897 (PROD:26897)
diff --git a/linux/meta/fluentd.yml b/linux/meta/fluentd.yml
index 60d2ef5..a4b111f 100644
--- a/linux/meta/fluentd.yml
+++ b/linux/meta/fluentd.yml
@@ -98,12 +98,20 @@
                 result: $1.systemd
   {%- if pillar.get('telegraf', {}).get('agent', {}).get('enabled', False) %}
           push_to_telegraf:
-            require_in:
-              - push_to_default
+            require:
+              - rewrite_tag
             tag: 'telegraf.systemd'
             type: relabel
             label: telegraf
   {%- endif %}
+  {%- if pillar.get('prometheus', {}).get('exporters', {}).libvirt is defined %}
+          push_to_libvirt:
+            require:
+              - rewrite_tag
+            tag: 'libvirt-exporter.systemd'
+            type: relabel
+            label: libvirt_exporter
+  {%- endif %}
           push_to_default:
             tag: '*.systemd'
             type: copy