ceilometer: add reference to event_pipeline

event_pipeline.yaml file was added to ceilometer in Kilo to control
processing of events. this patch adds reference to it and explains
how it works.

Change-Id: Ic58aa7cda907672dca66752f6bb2ba72804cc8d1
Closes-Bug: #1436484

doc/admin-guide-cloud/telemetry/section_telemetry-data-collection.xml

@@ -490,16 +490,17 @@
       <xref linkend="section_telemetry-publishers"/>.</para>
     <section xml:id="section_telemetry-pipeline-configuration">
       <title>Pipeline configuration</title>
-      <para>Pipeline configuration by default, is stored in a separate configuration
+      <para>Pipeline configuration by default, is stored in separate configuration
-        file, called <filename>pipeline.yaml</filename>, next to the
+        files, called <filename>pipeline.yaml</filename> and
-        <filename>ceilometer.conf</filename> file. The pipeline
+        <filename>event_pipeline.yaml</filename>, next to the
-        configuration file can be set in the <option>pipeline_cfg_file</option>
+        <filename>ceilometer.conf</filename> file. The meter pipeline and event pipeline
-        parameter listed in the <link xlink:href=
+        configuration files can be set by the <option>pipeline_cfg_file</option>
+        and <option>event_pipeline_cfg_file</option> parameters listed in the <link xlink:href=
         "http://docs.openstack.org/juno/config-reference/content/ch_configuring-openstack-telemetry.html"
         >Description of configuration options for api table</link> section in the
-        <citetitle>OpenStack Configuration Reference</citetitle>. Multiple chains
+        <citetitle>OpenStack Configuration Reference</citetitle> respectively. Multiple pipelines
         can be defined in one pipeline configuration file.</para>
-      <para>The chain definition looks like the following:</para>
+      <para>The meter pipeline definition looks like the following:</para>
       <programlisting>---
 sources:
   - name: 'source name'
@@ -613,6 +614,19 @@ sinks:
       </table>
       <para>The publishers section contains the list of publishers, where the samples data should
         be sent after the possible transformations.</para>
+      <para>Similarly, the event pipeline definition looks like the following:</para>
+      <programlisting>---
+sources:
+  - name: 'source name'
+    events:
+      - 'event filter'
+    sinks
+      - 'sink name'
+sinks:
+  - name: 'sink name'
+    publishers:
+      - 'list of publishers'</programlisting>
+      <para>The event filter uses the same filtering logic as the meter pipeline.</para>
       <section xml:id="section_telemetry-pipeline-transformers">
         <title>Transformers</title>
         <para>The definition of transformers can contain the following fields:</para>

doc/config-reference/telemetry/section_telemetry-sample-configuration-files.xml

@@ -36,7 +36,15 @@
           samples generated by the Telemetry module</para>
         <programlisting language="ini"><xi:include parse="text" href="http://git.openstack.org/cgit/openstack/ceilometer/plain/etc/ceilometer/pipeline.yaml?h=stable/juno"/></programlisting>
     </section>
-    <!-- TODO(gordc): add event_pipeline.yaml for kilo -->
+    <section xml:id="section_event_pipeline.yaml">
+        <title>event_pipeline.yaml</title>
+        <para>Event pipelines describe a coupling between notification event_types
+            and the corresponding sinks for publication of the event data. They are
+            defined in the <filename>event_pipeline.yaml</filename> file.</para>
+        <para>This file can be modified to adjust which notifications to capture and the
+          and where to publish the events.</para>
+        <programlisting language="ini"><xi:include parse="text" href="http://git.openstack.org/cgit/openstack/ceilometer/plain/etc/ceilometer/event_pipeline.yaml"/></programlisting>
+    </section>
     <section xml:id="section_ceilometer-policy.json">
         <title>policy.json</title>
         <para>The <filename>policy.json</filename> file defines additional