Make ceilometer sample interval configurable

This could already be configured via the ceilometer_pipeline_yaml_overrides
in theory, but in practice this is very unpractical as one would have to
override the whole sources configuration. Only overriding one key in a
list of dicts is not possible.

Change-Id: Ieb5569982f080446295cecc33fb70c6b5d1cb9d6

defaults/main.yml

@@ -122,6 +122,13 @@ sahara_ceilometer_enabled: false
 ceilometer_aodh_enabled: false
 ceilometer_gnocchi_enabled: false
 
+# Sampling interval for ceilometer-polling services
+ceilometer_sample_interval: 600
+ceilometer_meter_sample_interval: "{{ ceilometer_sample_interval }}"
+ceilometer_cpu_source_sample_interval: "{{ ceilometer_sample_interval }}"
+ceilometer_disk_source_sample_interval: "{{ ceilometer_sample_interval }}"
+ceilometer_network_source_sample_interval: "{{ ceilometer_sample_interval }}"
+
 ## Keystone authentication middleware
 ceilometer_keystone_auth_plugin: password
 

releasenotes/notes/configure-polling-sample-interval-54b2fb66140b4220.yaml

@@ -0,0 +1,6 @@
+---
+feature:
+  - |
+    Support has been added to configure the sampling intervall for
+    ceilometer-polling by setting ``ceilometer_sample_interval``.
+    See the Ceilometer role documentation for per source options.

templates/pipeline.yaml.j2

@@ -1,20 +1,20 @@
 ---
 sources:
     - name: meter_source
-      interval: 600
+      interval: {{ ceilometer_meter_sample_interval }}
       meters:
           - "*"
       sinks:
           - meter_sink
     - name: cpu_source
-      interval: 600
+      interval: {{ ceilometer_cpu_source_sample_interval }}
       meters:
           - "cpu"
       sinks:
           - cpu_sink
           - cpu_delta_sink
     - name: disk_source
-      interval: 600
+      interval: {{ ceilometer_disk_source_sample_interval }}
       meters:
           - "disk.read.bytes"
           - "disk.read.requests"
@@ -27,7 +27,7 @@ sources:
       sinks:
           - disk_sink
     - name: network_source
-      interval: 600
+      interval: {{ ceilometer_network_source_sample_interval }}
       meters:
           - "network.incoming.bytes"
           - "network.incoming.packets"