Monitor only pillar-defined interfaces.

Fixes PROD-34929

Change-Id: I087102f8017af927d853da65a33d0a0e8a092f67
diff --git a/linux/meta/telegraf.yml b/linux/meta/telegraf.yml
index 9a25b69..1aee1d5 100644
--- a/linux/meta/telegraf.yml
+++ b/linux/meta/telegraf.yml
@@ -24,7 +24,12 @@
         - overlay
     diskio:
     kernel:
+{%- set net_ifaces = [] %}
+{%- for iface_name, iface_data in network.interface.items() %}
+  {%- do net_ifaces.append(iface_data.get('name', iface_name)) %}
+{%- endfor %}
     net:
+      interfaces: {{ net_ifaces|json }}
     mem:
     nstat:
       fieldpass:
diff --git a/tests/test-requirements.txt b/tests/test-requirements.txt
index 0480052..bc7dc7f 100644
--- a/tests/test-requirements.txt
+++ b/tests/test-requirements.txt
@@ -1,3 +1,4 @@
 jsonschema
 reno
-setuptools<45.0.0
\ No newline at end of file
+setuptools<45.0.0
+msgpack<1.0.0