collectd: Configure the processes plugin

The *processes* plugin for collectd can be configured to monitor
additional information about specific processes.  By specifying one or
more `Process` or `ProcessMatch` directives in the plugin configuration,
collectd will start monitoring the listed processes in detail.

The `collectd_processes` Ansible variable can contain a list of
processes to monitor.  Each item must at least have a `name` property,
and may also have a `regex` property.  If the latter is present, a
`ProcessMatch` directive will be emitted instead of a `Process`
directive.

roles/collectd/tasks/main.yml

@@ -33,6 +33,16 @@
   tags:
   - collectd-config
   - collectd-network
+- name: ensure colelctd processes plugin is configured
+  template:
+    src: collectd-processes.conf.j2
+    dest: /etc/collectd.d/processes.conf
+    mode: '0644'
+  notify:
+  - restart collectd
+  tags:
+  - collectd-config
+  - collectd-processes
 
 - name: ensure collectd starts at boot
   service: