Add host label to influxdb_relay targets

Change-Id: Ic6522dd24b957cc486a84f6e816012e761ddac77
PROD-related: PROD-18671
diff --git a/influxdb/meta/prometheus.yml b/influxdb/meta/prometheus.yml
index affbd77..d86de7a 100644
--- a/influxdb/meta/prometheus.yml
+++ b/influxdb/meta/prometheus.yml
@@ -152,6 +152,11 @@
         endpoint:
         - address: {{ addresses[0] }}
           port: {{ relay.telemetry.bind.port }}
+        relabel_configs:
+          - regex: {{ addresses[0] }}:{{ relay.telemetry.bind.port }}
+            replacement: {{ grains['host'] }}
+            source_labels: "__address__"
+            target_label: "host"
 
 {%- endif %}